lab 1
Which 2 main genres form endospores?
Bacillus & Clostridium
Gamma-hemolytic
Bacteria that cause no change in blood agar
What is the reagent in the VP test?
Barretts Reagent A Barretts Reagent B
Schistosoma
Blood Fluke
Proglottids
Body segments of a worm
Clostridium Botulinum
Botulism
Nostoc
Bright Blue Curly "q's"
which endospore forming bacteria causes deadly diseases?
C. perfringens , B. cereus
Iodine
Chemical that causes starch to turn brown-black if present in Amylase test
Spore-forming species
Clostridium & Bacillus
Endo Agar
Coliforms produce a gold metallic sheen in which test medium?
Yellow
Color Mannitol/Salt agar turns when mannitol is fermented by the bacteria on it
What is the best way to visualize capsules?
Combine a negative stain and a simple stain
What occurs in β-hemolysis?
Complete destruction of RBCs and hemoglobin
Diatoms
Cool Shapes
Primary stain
Crystal Violet/Gram +/1 min
a key for the identification of organisms based on a series of choices between alternative characteristics
Define Dichotomous key
DNase agar - enzyme?
Deoxyribonuclease
Citrate Utilization Test
Differentiates the ability to ferment citrate as a sole carbon source (+) blue -- E. aerogenes (-) green -- E. coli
No
Does staphylococcus epidermidis cause hemolysis?
Casein Hydrolysis
Does this organism produce the enzyme casease?
Gas tubes in some phenol red tests that collect a bubble of gas if bacteria in them produce gas upon fermentation of carbohydrates
Durham gas tubes
What organism tends to produce a green metallic sheen on EMB?
E. coli
EMB plate select for what group of bacteria
E.coli antibacterial
**Selects for gram - ***Differential for lactose, lactose + = red colonies and surrounding medium **Coliforms produce a gold metallic sheen
Endo Agar test
True/False: Aspergillus flavus causes ergot poisoning.
False
Station 16 Malaria Vector
Female Anopheles mosquito
What is the hydrogen sulfide indicator in TSIA?
Ferrous sulfate
Contaminated inanimate object
Fomite
"Microscopic Inversion"
From what is seen with the naked eye, whatever is being viewed under Brightfield Microscope is rotated 180 degrees and moves left when shifting right.
Neisseria
GN diplococcus
Hemophilus
GN pleomorphic rod
Enterobacter
GNR
Escherichia coli
GNR
Klebsiella pneumonia
GNR
what does a mordant do?
Helps lock in the dye to the cell wall
Ancylostoma
Hookworm
10 years with no symptoms
How long does the incubation period of HIV last sometimes?
Ascaris
Human Roundworm
What reagent is used for a catalase test?
Hydrogen peroxide
what does heat-fixing do?
"fixes" the bacteria to the slide so they do not move and can retain their original shape
In lab 9, what was the name of the person who originally had the disease?
"patient zero"
Triple Sugar Iron (TSI) test, Hydrogen sulfide, yellow = +
(agar inside tubes) What test? What causes one tube to turn black? What color is positive?
(Antimicrobial agent) Inhibition of nucleic acid synthesis EXAMPLE
**Cipro [Ciprofloxacin]
Result of Gram Stain
-Staph epid (gram+ cocci) are stained purple from the Crystal Violet (due to thick cell walls) -E. coli (gram- rods) are stained red from the Safranin
BA - gamma hemolysis
-no hemolysis - turn into white colonies
Mycotoxicoses
-occur following consumption of food that has been poisoned by fungal toxins (mycotoxins) -examples: Aspergillus flavus & Claviceps purpurea
Motility Test - motile negative?
-organism will only grow along the streak line -medium will NOT be cloudy
Darkfield Microscope
-specimens appear bright against a dark background -observes LIVE specimens -doesn't require staining
What two items did we use in lab to make E.coli competent?
-transforming solution (CaCl2) -heat shock
Microsporum (Tinea capitis)
-type of mycoses = cutaneous -phylum = Deuteromycota -entry route = direct contact (skin) -treatment - Nystatin -disease = Ringworm; Athlete's foot
Sporothrix schenckii (Fungus) disease = Sporotrichosis
-type of mycoses = subcutaneous -phylum = Deuteromycota -entry route = direct contact (skin) -occupational hazard for gardeners -treatment = Amphotericin B and/or potassium iodide
Motility Test - procedure?
-use a needle to inoculate by making a single stab 2/3 down -incubate at optimum temp for 24-48 hrs
Amount plated will always be how many milliliters?
.1 or 10^-1
Factors that determine the efficiency of disinfectants and antiseptics
1. Concentration 2. Length of Exposure 3. Resistance 4. Temperature, pH, type of material
Name the steps of a Gram stain
1. Crystal violet (primary stain) 2. Gram's iodine (mordant) 3. ethanol (decolorizing agent) 4. safranin (counter stain)
What 3 bacterial activities does a SIM medium detect?
1. Sulfur reduction 2. Indole production from tryptophan 3. Motility
Making a Standard Smear
1. Tiny loop full of water on slide 2. Use sterile (heat) inoculation loop to transfer TINY amount of microorganism into water and spread into bigger circle. 3. Air dry slide COMPLETELY 4. Heat fix
How many WBCs are counted and tallied in a differential white cell count?
100
What total magnification is the Oil Immersion objective? What color is the ring?
1000X/Black
What total magnification is the low power objective? What is the color of the ring?
100X/Yellow
What is the diameter of all the granulocytes?
12-15 micrometers
What is the diameter of monocytes?
12-20 micrometers
What reagent is used for DNAse test?
1N HCl
How many lobes does the eosinophils have?
2
Binocular
2 occulars for depth perception
Acetoin & 2,3 butandiol
2 products detected in the Voges-Proskaeur Test
Normal % of lymphocytes?
25-33%
Dextrose (glucose), lactose, sucrose
3 carboydrates that produce enzymes during fermentation and can be tested in the lab
Pseudomonas aeruginosa, Escherichia coli, Staph. (aureus & epidermidis)
3 catalase positive bacteria
objective lenses
40x, 10x, 40x, 100x
URINE figure a colonie count?
50 colonies = 50,000 greater than 100,000 to be treated (colonies x 100,000)
Normal % of neutrophils?
55-65%
Phenol Red is pink above what pH?
7.4
Phenol red is red at what pH range?
7.4 - 8.4
E TV SLUMS 1. EMB (Eosin Methylene Blue) 2. TSI 3. VP 4. Sucrose 5. Lactose 6. Urease 7. Methyl Red 8. Simmons Citrate
8 Tests commonly run on Gram negative bacteria
Phenol red is pink above what pH?
8.5
What's the Rh factor?
A clumping factor in the blood.
Mycolic wax
Acid-fast microorganisms have a high ___________content in their cell walls, which resists staining.
Reason for extended heat in Acid-Fast Stain
Acid-fast species have a waxy cell wall, therefore color must be melted into the cell wall.
What are the color changes for neutral red?
Acid=hot pink Neutral=dusty rose Alkaline=tan
Bacillus Anthracis
Anthrax
Indirect ELISA test for...
Antibodies
The Kirby-Bauer test measures:
The effectiveness of antimicrobics against pathogenic microorganisms
In a Kirby-Bauer test, the zone of inhibition depends on:
The sensitivity of the bacteria to the specific antimicrobial agent
Epidemiology
The study of causes, occurrence, transmission, distribution, and prevention of disease.
What do ureases do?
They cleave urea into ammonia and carbon dioxide, causing an increase in pH
Hydrogen sulfide
This chemical is present if TSI agar turns black
??
This parasite only occurs in the United States and is the chief cause of morbid obesity.
E. coli and Proteus
This person has a UTI. What bacteria is causing it?
A+
This person has what type of blood?
True/False: Infected Anopheles mosquitoes can transmit malaria.
True
False
True/False: The "scotch tape test" is used to detect the presence of hookworms.
Station 5 Urease test Substrate
Urea
Station 5 Urease test Enzyme
Urease
Why did we use an index card or leave the lid on during the experiment?
We wanted to see growth of bacteria without UV light interaction
ELISA, Western blot as a confirmatory test
What are the 2 methods used to diagnose HIV?
BLUE= O2 present WHITE= No O2 present
What do the colors in the anaerobic jar indicate?
Facultative anaerobe Growth with or without O2 Growth throughout test tube.
What organism does the broth show?
Detect the antibodies produced by our body to fight HIV.
What part of the virus does the Elisa test detect?
Positive: Staph Aureus Negative: Staph epidermis
What will the results of the Catalase test indicate?
Mutualism
When an organism benefits from us while giving us something in return
Parasitism
When an organism benefits from us while harming us
Commensalism
When an organism benefits from us without giving us anything in return
What is transformation?
When bacteria can pick up DNA from the environment and make use of the genes it carries
Streptococcus pneumoniae
Which bacteria is sensitive to Optichin or P disc antibiotic?
E. coli & Enterobacter
Which bacteria will grow on EMB?
Shigella Blue green color with no black precipitate due to NO H2S production.
Which enteric microorganism could be on this Hektoen media and why?
reproductive spores can become airborne leading to laboratory acquired respiratory infections
Why is it dangerous to work with pathogenic fungi in the laboratory?
How fast should a positive result appear for an oxidase test?
Within 20 seconds
Pandemics
Worldwide epidemics
Mannitol fermenter results in what color?
YELLOW
Station 2 Phenol Red media Negative result:
Yellow - has used carbohydrate, produced acid
What method do we use for the acid fast stain?
Ziehl-Neelsen
Where growth is inhibited
Zone of inhibition
What do Gram +'s have that Gram -'s don't
a thick cell wall that contains peptidoglycan and teichoic acid that holds in the crystal violet
A disease such as AIDS will make a patient susceptible to a respiratory disease called: a. PCP b. jock itch c. ringworm d. ergot
a. *PCP* b. jock itch c. ringworm d. ergot
Voges-Proskauer "MR-VP Broth" - purpose?
ability of an organism to produce acetoin, 2,3 butanediol
Methyl Red Test "MR-VP Broth" - purpose?
ability of an organism to produce mixed acid fermentation
Urea Hydrolysis "Urea Broth" - purpose?
ability of an organism to split urea to form ammonia "alkaline" by the action of urease -medium contains phenol red - turn pink in alkaline conditions
Resolution
ability of lens to distinguish between objects close together expressed as a distance
Nitrate Reductase Test (Nitrate Broth) - purpose?
ability of organism to reduce nitrate (NO3) to nitrite (NO2) or N2 by production of nitratase
define competency
ability to take and express recombinant DNA
Citrate Utilization - positive result?
alkaline pH makes it change from green to Prussian blue
What are obligate aerobes?
bacteria that require oxygen to grow, so they grow at the top of the tube and often the methylene blue is gone.
Hemophilis influenza
bacterial meningitis
Crystal Violet - primary dye
basic and carries positive charge. interacts with negatively charged cell wall
H2S+ =
black precipatiate
Microscope eyepiece
contains a 10x lens
URINE if plate contains multiple organisms you would report?
contamination
Rheostat?
controls light density, less light intensity will be needed with low power objectives
What does Hemolysin do?
destroys rbc's
Fluid Thioglycollate Medium "Oxygen Requirements" What does this medium used for?
determiine oxygen requirement of medium
Motility Test - purpose?
determine whether or not an organism is motile
red blood cell
disc shaped
Gelatinases hydrolyze
gelatin
Neisseria gonorrhea
gonorrhea
how long can endospores last?
indefinitely
antibodies used the diagnostic kits are made how
injecting rabbits with the antigen
EMB agar - differential agents
lactose and sucrose
Agranulocytes
lymphocytes monocytes
BA - complete hemolysis "beta"
lyses cell membranes of all RBC's
colony forming units (CFU) =
number of colonies counted divided by the amount plated in ml times the dilution (# colonies counted/(amt plated x dilution))
What makes DNA negative?
phosphate group (PO4-)
What does catalase do?
protects a cell against hydrogen peroxide by breaking it down into water and oxygen
gram positive rod
purple
What color do eosinophils stain?
red
gram negative cocci
red round shaped
What is Counterstain
safranin/1 min
HE agar selects of bacteria
seracisous marcesci
define inoculum
small number of cells added to a sterile medium to create a pure culture
what does the media in citrate utilization contain
sodium citrate- carbon source. ammonium dihydrogen phosphate- nitrogen source. bromothymol blue- pH indicator.
if an organism is a non-ferreter what would you see in a macconkey agar part
tan
Direct ELISA - what are we testing for?
test for antigens "pathogen"
On what basis are the protozoa classified?
the 4 classes of protozoans are based on their type of motility
What is minimum inhibatory concentration (MIC)?
the exact value of the smallest amount of antibiotic that kills/inhibits the microorganisms
What does the EMB medium have?
the medium has two indicators dyes eosin and methylene blue.
Oxidase Test - purpose?
to see if an organism is an aerobe -it checks for the ETC
What is the total dilution of the following dilutions: 1/100 X 1/10 X 1/10 X 1/10 X 1/10 X 1/10 X 1/10
total dilution = 1/100,000,000
What is a positive test in the ELISA test look like?
turn a blue color
Salmonella typhi
typhoid fever
proteus mirabilis changes broth to bright pink, this is a positive result.
urea broth
Most effective antibiotic:
varies... see results chart
Least effective antibiotic:
varies...see results chart
Aerial hyphae goes
vertically
Results of LB/AMP/ARA with + pGLO?
very active growth and will glow
Do bacteria have the ability to produce endospores?
yes long gram positive rods produce endospores
Since agar is not degraded by most bacteria, can it be liquified
yes, at 100 degree Celsius. it will remain a liquid at temperatures above 40 degree Celsius, allowing growth media to be poured into petri plates or tubes.
Test #2-Indole Test
•AKA tryptone •indicates the ability of bacteria to conver tryptophane → indole •KOVACS REAGENT is addded to detect indole → red lining •All ESCHERICHIA COLI , by definition, are indole positive.
What shape is spirillum/Spirilla (pleural)
"S" shaped
(Antimicrobial agent) Disruption of cell membrane function EXAMPLE
**Anti-fungal Drugs (such as ClotrimAZOLE, MiconAZOLE, KetaconAZOLE)
(Antimicrobial agent) Inhibition of cell wall synthesis EXAMPLE
**Penicillin (or Cephalosporins, Vancomycin, INH)
(Antimicrobial agent) Interference with enzyme function EXAMPLE
**Sulfa Drugs [Sulfonamides]
(Antimicrobial agent) Inhibition of protein synthesis EXAMPLE
**Tetracyclines (such as Minocycline & Doxycycline)
Staphyloslide Latex Agglutination Test
**wear gloves -when Staph aureus' surface proteins bind with human IgG antibodies, results in agglutination -Staph aureus is the ONLY positive reaction -Positive: speckled, agglutinated dots -Negative: no/almost no speckled dots
ELISA test in lab - 5 steps.
*3 drops of antigen *3 drops of patient's serum and also a +/- control *3 drops of antibodies linked with enzyme *3 drops of chromagen *wait 5 minutes for results
3 differential stains
*Acid Fast *Spore Stain *Gram Stain
A red color after reagents in a nitrate test indicates:
+ Nitrate reduction to nitrite
No color change after reagents and zinc in a nitrate test indicates:
+ Nitrate reduction to nongaseous nitrogenous compounds
Tapeworm Scolex
-"head end" of tapeworm -note hooks and suckers -member of Platyhelminthes -used to attach to intestinal wall
Cestodes (tapeworms)
-20-30 feet in length -most are hermaphroditic (this allows for self-fertilization) -characterized by having a head end (scolex) which contains hooks and suckers used for attachment to intestinal wall and a body that's divided into segments (proglottids) -these units contain the reproductive and digestive systems of the worm -the scolex MUST be removed to ensure elimination of worms since as long as it remains attached, proglittids will continually be formed and released
Aspergillus Species (mold)
-A. niger a common black mold (causes "moldy" bread) -A. fumigates can cause respiratory problems (aspergillosis) -A. flavis can produce a poisonous aflatoxin -Aflatoxin may contaminate peanut butter, peanuts, rice, grains -toxin in grains responsible for large wild bird kills -supportive treatment -inhalation of spores or consumption of toxin if food *note the "starburst" conidiophore*
Kirby-Bauer/"Disk Diffusion Method"
-Accounts for many variables that may impact test results -Mueller-Hinton agar -4mm thick -pre-soaked absorbent paper disks -agar thoroughly covered in microorganism with cotton swab -16 to 18 hours incubation -measure zones of inhibition in millimeters and compare to specific diameters in standardized table
What allows the test for ELISA to be (+)?
-Antigen is in the well...when patient has the antibody it will bind with the antigen. -once the antibody linked with enzyme enters, this will attach to the patients antibody. -when chromagen enters it will react with the enzyme that is attached the the complex and show a blue color
Oxygen Requirements "Fluid Thioglycollate Medium"
-Areobes -growth on top-pseudomonas aerigenosa -Facultative-growth throught the medium-Staphylococcus aureus & E. coli -Anaerobes-growth on bottom-Clostridium
ONPG Test
-B-galactosidase breaks down lactose.
Results of Blood Agar Hemolytic Types
-Beta: RBC completely destroyed -Alpha: RBC partially destroyed -Gamma: no RBC destruction
Types of Hemolysis (Results of Blood Agar)
-Beta: clear (maybe yellow) zone around colonies... b/c RBCs completely destroyed -Alpha: greenish-gray zones... b/c RBCs partially destroyed -Gamma: really no change... b/c no RBC destruction
Sterile Specimen Collections
-Blood & other [internal] body fluids (CSF, synovial, pleural, ect.) -Urine: before voiding and if clean catch, midstream -[Deep] Wound specimen: not always sterile but normal flora are not expected
Results of Citrate Test
-Blue: Citrate positive -Green: Citrate negative **if there is any blue on a Citrate agar plate = Citrate positive
Oxygen Requirements "Fluid Thioglycollate Medium"
-Boil 5 min -loose cap -tighten cap -Allow to cool -donot shake incubate 24hrs
Match the items listed in the "KEY" below to answer questions KEY: a. Candida b. Balantidium c. Cryptococcus d. Schistosoma e. Wucheria -Can be acquired from breathing contaminated bird feces -Can affect little children and cause diaper rash -Can cause swelling of body parts
-Can be acquired from breathing contaminated bird feces = C -Can affect little children and cause diaper rash = A -Can cause swelling of body parts = E
Match the items listed in the "KEY" below to answer questions KEY: a. Sporotrichosis b. Bilharzia c. Schistosomiasis d. Pinworms e. Trichinosis -Causes intense anal itching. -Is caused by a fungus which is an occupational hazard for gardeners. -The larvae burrow through your skin when you wade in contaminated water. -May cause "swimmers itch". -Acquired from eating contaminated pork and other meats.
-Causes intense anal itching = D -Is caused by a fungus which is an occupational hazard for gardeners = A -The larvae burrow through your skin when you wade in contaminated water = B -May cause "swimmers itch" = C -Acquired from eating contaminated pork and other meats = E
Ways to improve resolution on Brightfield Microscope
-Condenser lens as high as possible -Diaphragm opened to shine as much light as possible -Use immersion oil to reduce scattering of light
Trypanosoma brucei, gambiense, and rhodesiense (Mastigophora-Flagellate)
-DISEASE = African sleeping sickness -GENERAL SYMPTOMS = severe anemia leading to fatigue, weakness, coma, and death; neural; circulatory -TRANSMISSION = Tsetse fly bite; cattle and wild animals represent nartural reservoirs -TREATMENT/PREVENTION = avoid fly bites; Suramin and melarsoprol
Food Microbiology - Serial Dilution and Plate Counting
-Dilution Tubes - 9 ml saline tubes -Dilutions made with 1 ml pipettes -Plate Counting: 30-300 colonies -Quebec Colony Counters used -formula: Milk: TVB/ml = PC X DF Meat: TVB/gm = PC X DF
Which of the parasites studied commonly occur in the United States?
-E. histolyticum -B. coli -Giardia -Trichomonas -Trypanosoma cruzi -Toxoplasma gondii -Cryptosporidium; Plasmodia
Balantidium coli (Ciliate) DISEASE = Balantidasis or balantidial dysentery
-GENERAL SYMPTOMS = intestinal infection; may cause ulceration of GI tract -TRANSMISSION = contaminated food/water; poor hygiene -TREATMENT/PREVENTION = Metronidazole; Chlortetracycline -forms both trophozoites and cysts -normal intestinal inhabitant in swine and frogs -the only ciliate to cause disease *very large, round to oval parasites w/macronuclei*
Trichomonas vaginalis (Mastigophora-Flagellate) DISEASE = Vaginitis; UTI
-GENERAL SYMPTOMS = itching; pain; foul discharge -TRANSMISSION = sexual contact -TREATMENT/PREVENTION = abstinence; Metronidazole -opportunistic parasite that can invade when acidity of urinary tract changes *look for large oval flagellated cells*
Endamoeba histolyticum (Amoeba) DISEASE = Amebiasis or amoebic dysentery
-GENERAL SYMPTOMS = severe intestinal disease; ulceration and perforation of GI tract -TRANSMISSION = contaminated food/water; poor sanitation; filth -TREATMENT/PREVENTION = Metronidazole *look for oval cells with nuclei* *see both cysts and trophozoites*
Leishmania donovani & tropica (Mastigophora-Flagellate) -DISEASE = Leishmaniasis -visceral disorder called Kala-azar (caused by donovani); skin sores (tropica causes Oriental sores)
-GENERAL SYMPTOMS = systemic -TRANSMISSION = Phlebotomus sand flies -TREATMENT/PREVENTION = avoid sand fly bites; chemo; surgery -common in Asia, Africa, & Middle East -tissue section; amastigote form *look for very tiny Donovan's bodies*
Psuedomonas aeroginosa
-Gram (-) rod -Green pigment -Fruity odor -Resistant to many antibiotic; only sensitive to Cipro -Common in ICU, trauma, and burn units
Match the items listed in the "KEY" below to answer questions KEY: a. Protozoan b. Tapeworm c. Fungus d. Fluke -Histoplasma capsulatum -Fasciola hepatica -Giardia intestinalis -Taenia solium
-Histoplasma capsulatum = C -Fasciola hepatica = D -Giardia intestinalis = A -Taenia solium = B
Result of Capsule Stain
-India Ink (- charge) stains the background a dark [black-ish] color -Crystal Violet (+ charge) stains Bacillus Megaterium blue
Antimicrobial Agents: Mechanisms of Action
-Inhibition of cell wall synthesis -Inhibition of protein synthesis -Disruption of cell membrane function -Inhibition of nucleic acid synthesis -Interference with enzyme function
Slide agglutination test
-Known antibodies are mixed with the organism in question -Positive: speckled, agglutinated dots -Negative: no/almost no speckled dots
Positive bacteria for Snyder test
-Lactobacilli -Oral Streptococcus mutans
Result of Endospore Stain
-Malachite Green stains Bacillus Megaterium and its endospore green then water decolorizes this water soluble stain out of the bacteria but leaves the spore green -Safranin stains the bacteria red
Nucleic Acid Test
-Patient DNA/RNA compared to known DNA/RNA of organism in question -Ex: Gonorrhea, Syphilis, etc.
Results of MacConkey Agar
-Pink: positive; ferments lactose -Flesh-like/no color: negative; does not ferment lactose
Classification of Helminthes
-Platyhelminthes (flatworms) -Nemathelminthes (roundworms) -each is further divided into classes: 1. tapeworms = Cestoda 2. flukes = Trematoda 3. roundworms = Nematoda
Match the disease to the appropriate method of treatment/prevention/diagnosis: a. wind up on a stick b. control "no see um" sand flies c. use antifungal ointment d. use scotch tape e. hope for the best -Ringworm infections -Pinworm infections -Oriental sores -Guinea worm infections -Naegleria infections
-Ringworm infections = C -Pinworm infections = D -Oriental sores = B -Guinea worm infections = A -Naegleria infections = E
Result of Acid-Fast Stain
-Staph epid (non acid-fast, gram+ cocci) are stained blue from the Methylene Blue (first stained red by Carbofuchin then decolorized by the acid alcohol and stained with Meth Blue) -Mybacterium (acid-fast rods) are stained red from the Carbofuchsin
MSA - example bacteria
-Staphylococcus aureus - yellow "low pH" - positive for fermentation - Staphylococcus epidermis - pink "high pH" -negative for fermentation
Normal Flora Present Specimen Collections
-Throat swab -Sputum -Fecal (stool) -Vaginal
Antibody-Based Quick Strep Test
-Top line will always show, meaning test worked -2nd line shows, meaning Positive reaction
Catalase Test
-Used along w/other Gram (+) tests -Used to tell between Staph (catalase +) and Strep (catalase -) -Converts Hydrogen Peroxide to water and oxygen
Coagulase Test
-Used to specify types of Staph -Staph aureus is the ONLY positive reaction; all other Staph are negative -Positive: clumps up (clots) -Negative: doesn't clump (clot) -Uses Rabbit Plasma (contains fibrin: clotting factor)
Results of Mannitol Salt Agar Test
-Yellow: positive; ferments mannitol -Pink: negative; does not ferment mannitol -Growth: salt tolerant -No growth: not salt tolerant
ELISA direct test
-add patient serum (if + it will have Ag) -add antibody with linked enzyme -add chromagen -wait for color change
Helminth Reproduction/Life Cycles
-adult parasites may exhibit separate sexes or have both combined w/in one animal (hermaphroditism) -production of thousands of eggs (ova) which may be released in stool of host -man may harbor adult parasites or some other form including the larvae -some utilize intermediate hosts such as snails or fish to maintain life cycle
Toxoplasma gondii (Apicomplexa) DISEASE = Toxoplasmosis
-affects any organ of body especially brain, heart, and lymphatics; congenital defects -TRANSMISSION = infected cats; cat feces; under-cooked meat -Sulfonimides -affects immune compromised, fetus of pregnant women *look for crescent-shaped parasites*
Protozoan Structure
-all protozoa possess a cell membrane or a pellicle and one or more nuclei w/in cytoplasm -obtain food by ingestion, diffusion thru cell membrane, pinocytosis, or phagocytosis (amoebas)
What is the primary difference between arachnids and the insects?
-arachnids possess 4 pairs of legs, 2 mouth parts, no antennae -insects possess 3 body parts, 6 legs, antennae, and mandibles or jaws
Treatment/Prevention of Mycoses
-avoiding inhalation of asexual spores found in dust -treatment depends on the body area or tissue involved -topical ointments: tinactin and griseofulvin used for CUTANEOUS -amphotericin B, nystatin, and the azoles (ketoconazole) for SYSTEMIC
Nitrate Reductase Test - procedure?
-boil 5 minutes -tighten cap and let cool -inoculate broth -incubate at optimum temp -add 5 drops each of Nitrate Reagent A and B
Citrate Utilization - contents?
-carbon source -sodium citrate -nitrogen source -ammonium salts -pH indicator -brom thymol blue
Disease: Cysticercosis
-causative agent = Taenia solium -mode of transmission = ingestion of pork containing tapeworm eggs - treatment = none
Naegleria fowleri (Amoeba)
-causes amoebic meningo-encephalitis -naturally in brackish, muddy water of ponds and lakes and invade sinuses of normal healthy children
Trypanosoma cruzi (Mastigophora-flagellate) DISEASE = Chagas disease
-causes ulcers; cardiovascular; bite and then fecal deposit of Triatomid/Conenose bug -treatment/prevention = avoid bug bites; reservoirs seem to be small rodents, opossums, & armadillos; endemic in Mexico and S and Central America (myocarditis) *look for flagellated crescent-shaped parasites in blood smear*
Why are stool samples concentrated to demonstrate intestinal parasites?
-concentration increases the chances of finding the parasites -some stool samples may only contain a few making it difficult to identify
Cultivation and Dx of Mycoses
-cutaneous agents = wet mounts w/KOH or lactophenol cotton blue; fluorescent stains; tissue stains -systemic infections = lung aspirates; tissue biopsies; stains and X-rays -cultivation = Sabourauds dextrose agar and mycosel agar
Protozoan Cultivation and Dx
-depends on type of disease but variety of clinical samples (stool, blood, spinal, vaginal secretions) may be needed -various staining techniques used to observe them (hematoxylin or trichrome) -diagnosis following O & P (ova and parasite) check usually confirmed by observation of cysts or trophozoites in concentrated sample
Scanning Electron Microscope
-detailed 3D view of specimen's surface
EMB agar - purpose of differential agents?
-differentiate coliform -color change for fermentation
Tsetse Fly (Vector = Glossina Fly)
-disease association = African sleeping sickness (protozoa) -mechanical (M) or biological (B) = B -initial source of parasite = wild animals; cattle -arachnid or insecta = insecta -Suramin = treatment -transmits trypanosomes through bite -only occurs in Africa -causative agent = Trypansoma brucei gambiense & T. brucei rhodesiense *look for flagellated crescent-shaped parasites in blood*
Common House Fly (Vector = Musca & Sarcophaga)
-disease association = Amoebic dysentery (protozian cysts) and pinkeye (bacteria) -mechanical (M) or biological (B) = M (mechanically transmit anything -initial source of parasite = anywhere -arachnid or insecta = insecta *PEST*
Rat Fleas (Vector = Xenopsylla cheopis)
-disease association = Bubonic or Black Plague (bacteria); murine typhus (rickettsia) -mechanical (M) or biological (B) = B (may mechanicaly transmit tapeworms) -initial source of parasite = rats; rodents -arachnid or insecta = insecta (bloodsucking ectoparasites) -causes fever; rash -possess incredible jumping ability
Conenose bug or kissing bug (Vector = Triatomine bug)
-disease association = Chagas disease -mechanical (M) or biological (B) = B -initial source of parasite = rodents; unsanitary conditions -arachnid or insecta = insecta -transmits trypanosomes through bite and fecal deposit of parasites -found in Mexico, Central & South America & in TX -active @ night and inflicts painful bite
"Crab" or Pubic Lice (Vector = Phthirus Lice)
-disease association = Crabs -mechanical (M) or biological (B) = M -initial source of parasite = humans -arachnid or insecta = insecta -causes itchy infestation of skin, transmitted by close personal and sexual contact -eggs called nits and stick tightly to hairs of vicitm; treat w/Kwell
Mosquito (Vector = Aedes Mosquito)
-disease association = Dengue fever, Yellow Fever, & West Nile fever (transmits viruses) -mechanical (M) or biological (B) = B -initial source of parasite = animals; humans -arachnid or insecta = insecta -causes high fever; chills; pain
Body Lice (Vector = Pediculus Lice)
-disease association = Epidemic typhus (rickettsial); Relapsing fever (bacterial) -mechanical (M) or biological (B) = B -initial source of parasite = humans -arachnid or insecta = insecta -causes severe rash/fever -hide in clothing and have mouth parts adapted for sucking blood/tissue
Mosquito (Vector = Anopheles Mosquito)
-disease association = Malaria & elephantiasis (protozoa) -mechanical (M) or biological (B) = B -initial source of parasite = animals; humans -arachnid or insecta = insecta -causes high fever; chills
Hard Ticks (Vector = Dermacentor & Amblyomma ticks)
-disease association = Rocky Mountain Spotted Fever (rickettsia), Lyme Disease & Tularemia (bacteria); or viruses (encephalitis) -mechanical (M) or biological (B) = B -initial source of parasite = wild animals (small animals deer) -arachnid or insecta = arachnida -causes rash; fever; pain (infect man while feeding on blood) -transovarian transmission may occur
Scabies (vector = Sarcoptes mite)
-disease association = Scabies -mechanical (M) or biological (B) = M -initial source of parasite = rodents; animals -arachnid or insecta = arachnida -infests by burrowing into skin; highly contagious and cause intense itching -scratching aggravates condition -treat w/gamma benzene hexachloride (Kwell)
Cockroaches (Vectors = Blaberus & Blatta)
-disease association = none -mechanical (M) or biological (B) = M -initial source of parasite = unsanitary conditions -arachnid or insecta = insecta -Blatta acts as M vector for bacteria (salmonellois) and protozoa (amoebic dysentery); Blaberus acts as M vector for bacteria -primitive mouth parts and can ONLY be M vectors *PEST*
Sand Flies (Vector = Phlebotomus Flies)
-disease transmitted = Leishmaniasis (protozoa) -mechanical vector -causes oriental sores; systemic
Deer Flies (Vector = Chrysops)
-disease transmitted = Tularemia (bacteria), Loa Loa (filarial worms) -biological vector -causes Bobos; eye worm
Screwworm Flies (Vector = Cochliomyia Flies)
-disease transmitted = larvae cause worm myiasis -mechanical vector -causes flesh eating maggots (freely moving larvae)
Sand Fleas (Vector = Tunga Fleas)
-disease transmitted = none -mechanical vector -pest; produce intense itching leading to ulceration
Bedbugs (Vector = Cimex bugs)
-disease transmitted = none -mechanical vector carrying bacteria -pest
Soft Ticks (Vector = Ornithodorus tick)
-disease transmitted = rickettsia (tick paralysis) or bacteria (relapsing fever) -biological vector -infect man while feeding on blood
Trichomonas tenax (Mastigophora-Flagellate)
-disease= Gingivitis -symptoms= oral discomfort -transmission= kissing? -prevention= Good oral hygiene
Life Cycle of a Cestode
-distal, mature proglottids, which are filled w/eggs, may be shed in feces of host and if not properly disposed, could contaminate the soil or vegetation -the egg filled proglottids may be picked up by another unsuspecting host and cycle is complete
Why do we use bacteriostatic dyes in culture media? List two examples of media containing dyes.
-dyes provide a means of selection -dyes such as methylene blue and crystal violet inhibit G+ bacteria -examples: EMB, MAC
Life Cycle of a Trematode
-eggs produced by adult worms are eliminated in feces of infected animal -water access = eggs hatch into larvae called miracidia (infect aquatic intermediates -snails; crayfish) -change into infective larvae called cercaria; reenter new host by burrowing thru skin/ingestion of contaminated vegetation -larvae mature in blood stream into adults in host organs (liver, lungs, bladder) -after fertilization, female migrates to intestinal tract-releases eggs
Why are bacterial endospore monitoring devices more effective in evaluating sterility than heat sensitive tape?
-endospore devices react to pressure, temperature, and time -heat sensitive tape only reacts to temperature not pressure or time -therefore, the tape does not indicate sterility
Pneumocystis carinii (Opportunistic Fungus) disease = PCP; Pneumocystic pneumonia
-entry route = nasal -aerosols; compromised defense systems -common cause of death for patients with AIDS -Pentamidine and trimethoprim w/sulfa-methoxazole *lung smear of patient with PCP* *look for oval cysts in lung tissue*
Aspergillus Flavis (Mold)
-food poisoning (infected food entry) -Mycotoxicosis (produces carcinogenic mycotoxin called aflatoxin) -phylum =Ascomycota -elevated levels of aflatoxin in peanut butter, peanuts, rice, and cereal grains result in recalls *notice "starburst" conidiophore*
Cutaneous Mycoses (Dermatophytoses)
-fungi capable of degrading keratin and affecting skin, hair, or nails -infections commonly called tinea or ringworm since lesions tend to be circular -most infections respond to topical treatment, however oral griseofulvin may be used -transmitted directly via animal/human carriers thru infected hair or skin -example: Tinea capitis
Plasmodium malariae, falciparum, & vivax (Apicomplexa) DISEASE = Malaria
-general symptoms = fever; chills; weakness; vomiting -transmission= female Anopheles mosquito; treatment = Quinine derivatives -falciparum species highly resistant and often fatal species *look for rings/half moons in blood cells*
Endamoeba gingivalis (Amoeba) DISEASE = Oral Gingivitis
-general symptoms= oral discomfort -transmission = kissing -treatment/prevention = good oral hygiene
Systemic Mycoses
-generally begin as respiratory infections; but capable of dissemination to skin or other organs -inhalation of spores probable route of transmission -spores DO NOT seem to be contagious either from infected animals or humans -treatment = Amphotericin B -Cryptococcus (Filobasidiella) neoformans; Histoplasma capsulatum; & Coccidioides immitis
BA - incomplete hemolysis (alpha)
-greenish tinge -RBC's lyse midway -hemoglobin is reduced to methhemoglobin which is release through bilirubin
*Intestinal Nematodes*: Necator americanus & Ancylostoma duodenale (adult hookworms) *intestinal nematodes - note mouth parts and hooks*
-humans; dogs (penetration of infectious larvae while walking barefoot thru fecal contaminated soil) larvae migrate around tissue (cause cutaneous larva migrans); gain access to blood stream-to heart, lungs; coughed up, swallowed, & into intestines -abdominal pain; bloody diarrhea, anemia; Mebendazole & Ivermectin
Gelatinase - what can it do?
-hydrolyze gelatin into polypeptides -hydrolyze gelatin polypeptides into amino acids
Phase Contrast Microscope
-improved visual of internal details -observes LIVE specimens -doesn't require staining
Carbohydrate Fermentation Test - procedure?
-inoculate each medium with a wire loop -incubate at opt temp fro 24-48 hrs
Carbohydrate Fermentation Test - gas production?
-insert Durham tube which will capture some of the gas the organism produces
*Cestode*: Taenia saginata (beef tapeworm)
-intermediate host = cattle -mode of transmission = acquired by animals grazing on soil/vegetation contaminated by fecal wastes containing egg filled proglottids--these develop into larvae in animal intestines which migrate to muscle tissue and form cysticerci---man acquires by eating infected raw beef -symptoms/diagnosis = weight loss, abdominal cramps and gas -treatment/prevention = Niclosamide -may reach 36 feet *observe the scolex and proglottids*
*Cestode*: Echinococcus granulosis (Echinococcosis)
-intermediate host = dogs and cats -eggs of the worms released in stool & consumed by from direct contact w/animal or contaminated food; contact w/eggs on animal (infested dog) -hydatid cysts may form anywhere (brain, spleen, lungs) -surgery; Niclosamide *very short; look for scolex and proglottids*
*Trematode*: Fasciola hepatica (sheep liver fluke)
-intermediate host = fish; cercaria enter skin; causes severe liver damage -Bithional; avoid cercaria; Dehydroemetine (occurs in Asia, Australia) -adults release eggs in stool-contaminate water; eggs develop in snails; contaminate aquatic vegetation (sheep affected by consuming contaminated vegetation)
*Blood or Tissue Nematode*: Wucheria bancrofti (Elephantiasis)
-intermediate host = humans -mode of transmission = larvae of parasite are transmitted to new host by infected mosquitoes when feeds on bloody meal-travel to lymphatic vessels and into nodes where later develop into adults -swelling of extremities (edema); control mosquitoes; Diethylcarbamazine
*Cestode*: Taenia solium (pig tapeworm)
-intermediate host = pigs; man eats infected raw pork -first acquired by pigs consuming garbage or produce contaminated w/fecal waste w/egg filled proglottids-eggs hatch into larvae & migrate to tissue (now cysts) -muscle cysts; pain; cramps, and gas; Niclosamide *observe the scolex and proglottids*
*Trematode*: Schistosoma japonicum & mansoni (Adult Flukes) (Schistosomiasis & Bilharzia)
-intermediate host = snails -eggs hatch into miracidia & infect snails-reemerge as infective cercaria-man contacts cercariae by infected waters *a bird schistosome can cause "swimmers itch"* -intestines & liver; severe jaundice, abdominal pain, & anemia-Bithional; praziquantel
*Blood/Tissue Nematode*: Trichinella spiralis (Trichinosis)
-intermediate host-animals: pigs, bears, wolves -eating the encysted larvae in raw meat-cysts change to larvae in intestines, mature into adults and reproduce-eggs develop into larvae-enter lymph/blood/tissues -muscle pain, eye aches & fever; Mebendazole *note spiral worms in tissue section*
*Intestinal Nematode*: Trichuris trichiuria (whipworm or trichuriasis)
-intermediate host-humans; dogs; mode of transmission = larvae emerge from eggs, migrate to large intestine, & mature into adults--contact w/eggs on animals -diarrhea; abdominal pain; eggs or adult worms attached to mucosa -Mebendazole; good hygiene & sanitation; children at great risk (hand to mouth)
*Intestinal Nematode*: Enterobius vermicularis (enterobiasis or pinworms)
-intermediate host= humans (affects children) -poor hygiene; hand contact w/eggs-once consumed eggs hatch into adults in intestines; females migrate to anal region & deposit new eggs -anal itching; scotch tape test; Pyrvinium; Mebendazole; entire family needs tx *look for transparent oval sticky eggs*
*Intestinal Nematode*: Ascaris lumbricoides (Ascariasis or human roundworm disease)
-intermediate host= humans, dogs -consuming eggs that hatch into larva; later transform into adults; contact w/eggs on animals-complex life cycle - intestines to lungs back to intestines -abdominal pain-may become very active (crawl out); form obstruction -Mebendazole; Peperazine; citrate
Cryptosporidium parvum (Apicomplexa) DISEASE = Cryptosporidiosis
-intestinal infections especially in immune-compromised; diarrhea -contaminated water; community swimming pools -Nitazoxanide -opportunistic infections *trophozoite*
Why is it difficult to relate the effectiveness of a disinfectant tested in the laboratory to its effectiveness in actual use?
-it's difficult to simulate actual working conditions (too many variables) -need to control testing procedures to provide accurate comparative information
Protozoan Treatment & Prevention
-malaria prevented by quinine derivatives -amoebic dysentery, giardiasis, and trichomoniasis treated w/applications of metronidazole
In 21st Century America, why are we still concerned about tapeworm and roundworms infestations?
-many parasites utilize animal hosts -consequently, consumption of under-cooked, infected meat could result in infection -some parasites may also be found in fecal contaminated soil and water
Why do you suppose that meat samples can support a larger bacterial population than milk samples?
-meat provides all the available nutrients to bacteria -hamburger possesses more microbes because of the grinding process and the addition of air
Chiggers (vector = Trombicula mites)
-mechanical vector -their larva produce intense itching/inflammatory lesions
Head Lice (Vector = Pediculus Lice)
-mechanical vector spreading diseases such as impetigo and trachoma (treat w/insecticides) -itchy pest
Why are some arthropods mechanical vectors and others biological vectors?
-mechanical vectors have chewing mouth parts only and cannot transmit agents into the blood stream of their victims -biological vectors have piercing or sucking mouth parts which allow the agents access to the blood stream and/or access to the agents already in the blood stream (the agents can then use one victim for part of their life cycle and another victim for the remainder of their cycle)
The many variables accounted for in the Kirby-Bouer test [to prevent inaccurate results]
-medium used -diffusibility of antimicrobial agents through the medium -amount of antimicrobial agents used -number of microorganisms -time of incubation -measurement of zones of inhibition -interpretation of results
Nemathelminthes (roundworms or Nematodes)
-most numerous of multicellular parasites -characterized by having nervous and complete digestive system w/a true head, mouth parts, and anus -separate sexes and tough outer cuticle which resists intestinal enzyme degradation -ascarid roundworms produce large quantities of eggs that are released in stool of infected host
Are any parasitic diseases communicable from person to person?
-most parasitic diseases are not communicable -proper hand washing to avoid hand transmission is strongly advisable
Platyhelminthes (flatworms)
-most primitive of helminths -have a rudimentary digestive system w/only one opening and absorb food directly thru body wall -flattened dorsal-ventrally and shaped like a leaf (fluke) or tape measure (tapeworms) -have head region equipped with hooks and/or suckers
Transmission Electron Microscope
-most view in black & white -internal details are clearly visible -used to view viruses (b/c their very small)
Nitrate Reductase Test - positive confirmation test?
-no color change - organism reduced nitrate completely to ammonia and nitrogen gas
DNase agar - contents?
-nutrients for bacteria -DNA -methyl green -pH indicator that is a cation and will bind to the neg charged DNA
What are the laboratory procedures used for diagnosis and identification of protozoans?
-observation of intestinal parasites in concentrated stool samples -observation of blood parasites in blood samples -special serological lab tests
Helminth Diagnosis
-observation of larvae, adult worms, and/or eggs is indicative of infestation -stool, blood, or tissue samples may be tested -elevated eosinophil count is highly suggestive of active infection
Higher Parasites
-ones that affect humans commonly known as helminthes -possess organ systems -they have special attachment mechanisms such as hooks and suckers that allow them to adhere to host tissue; locomotion is minimal and depend on transfer from host to host by different means -Niclosamide used for tapeworm infections and Mebendazole for roundworm infections
Candida albicans (Yeast) disease = Candidiasis (mild skin infection) and thrush (oral) *note tiny oval yeast in center of field*
-opportunistic dimorphic yeast; Ascomycota -any entry route (found in GI and genitourinary tracts) -bartenders, dishwashers; immune compromised; overuse of antibiotics=yeast growth -oral/cutaneous infections=nystatin & antifungal creams; systemic infections=Amphotericin/azoles
Carbohydrate Fermentation Test - Acid Production?
-phenol red (pH indicator) -neutral - red -acidic - yellow
Antibiotic Sensitivity Testing
-plates swabbed with microbe prior to adding antibiotic disks -measure zone diameters (in mm) -compare clearing to chart to identify as: -resistant (R) -moderately sensitive (MS) -sensitive (S)
Could any protozoans be found normally on or in the human body? Which ones?
-possibly yes -E. gingivalis and Trichomonas hominus or tenax could be found in the oral cavity -their role in infection is not determined
Gram Stain Procedure
-prepare slide -drop of water -aseptic technique to add bacteria -heat fix -cool -add primary stain (crystal violet) and sit for 1 min -rinse with water -add mordant (Grams iodine) and sit for 1 min -decolorize with alcohol and sit for 30 sec -rinse with water -add counterstain (Safranin) and sit for 1 min -rinse with water -blot with absorbing paper
Of what importance is a protozoan cyst?
-protozoan cysts are very resistant to freezing, drying, polluted water, etc. -cysts provide a means for their transmission
How do the protozoans differ from bacteria?
-protozoans are eukaryotic, have a true nucleus, organelles, etc. -protozoans are much larger and more complex
Protozoan Cyst Formation
-resistant, dormant structures -covered by thick cell wall-like material called chitin which resists adverse conditions (freezing and polluted water) -form w/in intestinal tract of host and released in stool -consumption of food/water contaminated w/these will allow parasites to gain access to intestinal tract -they can then transform into free-living forms known as trophozoites
Giardia intestinalis or "lamblia" (Flagellate) DISEASE = Giardiasis
-severe prolonged intestinal dysentery -contaminated food/water- treat w/Metronidazole -cause intestinal infection (Beaver Fever); backpackers, hikers; maintained in wild animals *look for pear-shaped parasites with "eyes"-nuclei; can see trophozoites & very resistant cysts*
Why are some molds more capable of causing systemic infections than others?
-some are able to grow at 37 degrees C -some have thick cell walls that protect them from degradation and help them resist phagocytosis -some also have damaging extracellular enzymes -just the presence of fungi will cause a significant inflammation resulting in further tissue destruction
Why do organisms vary in their sensitivity to antibiotics?
-some organisms may possess plasmids which contain resistant genes -some organisms possess cell wall chemistry that is unaffected by the drug
Gelatin Liquefaction test - procedure?
-stab gelatin with organism using a needle -incubate at optimum temp for 24-48 hours -place tube in fridge for at least 30 minutes
Phenylalanine Deamination "Phenylaline Agar" - procedure?
-streak agar slant -incubate -add 5 drops of 10% Ferric Chloride on slant -wait 5 minutes
Compare the advantages and disadvantages of heat sensitive tape, chemical test strips, and endospore vials.
-tape = quick, easy to use, immediate information but limited sensitivity -test strips = quick, easy to use immediate, good sensitivity -endospore vials = easy to use, delayed results, certified test of sterility
Why are colonies found in the clear zones around an antibiotic disk important in the determination of sensitivity?
-the colonies represent resistant bacteria that formed into colonies -the antibiotic should not be used and the test should be recorded as resistant
Of what importance is antibiotic sensitivity testing to a physician?
-the test provides specific information as to the type of antibiotic that can be used in therapy -the physician is able to select the most appropriate drug that will be the most effective against the organism
Describe the difference between total count and viable count.
-total count = all microbes present, living or dead -viable count = only live microbes capable of producing colonies
A 1 milliliter sample of milk was diluted six times using 9 ml saline tubes. Duplicate samples were plated from the last three tubes. The plates were incubated and examined. The plate counts were: Tube 4 Tube 5 Tube 6 Plate A 812 116 26 Plate B 656 87 13 Determine the total number of bacteria per ml of original sample. *note: Tube 5 is used because the plate counts are between 30 and 300*
-total dilution = 1/10 X 1/10 X 1/10 X 1/10 X 1/10 X 1/10 -dilution factor = 100,000 PC (ave) = (116 + 87)/2 = 102 -total #/ml = 102 X 100,000 = 10,200,000 or 10.2 X 10^6
A 1 gram sample of hamburger was tested for bacterial count. The sample was first emulsified and diluted with a 99 ml bottle and further diluted using 5, 9 ml saline tubes. Duplicate samples were plated from the last three saline tubes. The plates were incubated and examined. The following plate counts were: Tube 3 Tube 4 Tube 5 Plate A: 792 220 17 Plate B: 985 175 28 Determine the total number of bacteria per gram of original sample. *note: Tube 4 is used because the plate counts are between 30 and 300*
-total dilution = 1/100 X 1/10 X 1/10 X 1/10 X 1/10 X 1/10 -dilution factor = 1,000,000 PC (ave) = (220 + 175)/2 = 198 -total #/gm = 198 X 1,000,000 = 198,000,000 or 19.8 X 10^7
Life Cycle of a Nematode
-transmitted to others via poor hygiene, flies, or feces (food/water) -after consumed, travel thru stomach to small intestine (hatch into tiny larvae) -penetrate mucous lining--enter the circulation--pass thru heart--into lungs -larval forms change in structure--travel up bronchi & trachea-coughed up & swallowed -finally end in intestinal tract again (where develop into adults)
Motility Test - motile positive?
-tube will appear red and cloudy -organism will spread over top of the medium
Cryptococcus Filobasidiella or Neoformans (Yeast) disease = Cryptococcosis
-type of mycoses = systemic -phylum = Basidiomycota -entry route = nasal -treatment = Amphotericin B and fluconazole -true yeast w/capsule -often disseminates to brain; transmitted from bird droppings (especially pigeons)
Coccidioides Immitis (Dimorphic) disease = Coccidioidomycosis (Valley fever)
-type of mycoses = systemic -phylum = Deuteromycota -entry route = nasal -treatment = Amphotericin B -in nature the fungus forms small arthospores which become airborne *arthrospores shown*
Histoplasma capsulatum (Dimorphic) disease = Histoplasmosis (Mississippi River Valley fever)
-type of mycoses = systemic -phylum = Ascomycota -entry route = nasal -infectious spores released in dust and inhaled by victim -one of most common respiratory fungal agents -treatment = Amphotericin B
Trematodes (flukes)
-un-segmented, covered by tough resistant cuticle, shaped like a leaf, and possess suckers -usually absorb food directly thru body wall -most flukes have separate sexes
Protozoa
-unicellular, eukaryotic organisms -only a few are of medical importance -generally unable to live independently of host and develop protective structures (cysts) to ensure survival -transmitted to host by vector (mosquitoes, flies, and ticks) -typically transmitted by contact w/human fecal matter -ectoparasites = those infecting skin/mucous membranes -endoparasites = those infecting internal organs or blood
Oxidase Test - indicator?
-uses an artifical electron acceptor -changes color to a dark blue/purple when its taken the last electron from cytochrome oxidase
Electron Microscope
-uses electron beams instead of light source: very short wavelengths so resolution and magnification are very good -views only DEAD specimens
Flourescence Microscope
-uses ultraviolet light source and "flourochromes" (flourescent stains) -helps quickly identify microorganisms: flourochomes naturally attach to specific microorganisms making them different colors
Claviceps purpurea (wheat rust)
-wheat fungus - forms black nodules called ergots -causes ergot poisoning (mycotoxicosis) -contracted by eating contaminated wheat and grains -poison causes severe circulation problems -may also be hallucinogenic
Opportunistic Mycoses
-when body's defenses against microbial invasion are weakened by malnutrition, cancer, radiation, or immunosuppressive drugs, normal flora initiate severe infections -examples: Candida albicans & Pneumocytis carinii
CITRATE TEST
..This test is among a suite of tests * Indole * (MR) Methyl-Red * (VP) Vogues-Proskauer * (Citrate) that are used to differentiate among the Gram-Negative bacilli in the family Enterobacteriaceae.
Normal % of basophils?
0.5-1%
Color indicators for VP testing
1 Rose Pink indicates the production of neutral end-products 2 No color change in the medium indicates
How many lobes do basophils have?
1 or 2
Normal % of eosinphils?
1-3%
The susceptibility of an organism to a drug is assessed by the size of the zone of inhibition, which is affected by:
1. Ability and rate of diffusion of the antibiotic into the medium and its interaction with the test organism 2. The number of organisms inoculated 3. The growth rate of the organism
Advantages of viable plate counts
1. Detects viable cells from dead cells 2. Isolate discrete colonies → pure colonies (helps facilitate identification)
2 forms of coagulase:
1. Free 2. Bound
Disadvantages of viable plate counts
1. Overnight incubation is time consuming 2. A lot of glassware is used 3. Greater manipulation→ increased counting errors
2 forms of the Coagulase Test:
1. Slide test 2. Tube test
Making a Capsule Stain
1. Tiny drop of INDIA INK (-) near on end of slide 2. Transfer BACILLUS MEGATERIUM into drop (do not smear with loop) 3. Use another slide to spread stain 4. Let air dry, heat fix, let cool 5. With slide on staining rack, flood smear with CRYSTAL VIOLET (+) and let sit for 1 minute 6. Tilt one end and rinse with water bottle 7. Blot dry 8. View under microscope OIL IMMERSION
Making a Negative Stain
1. Tiny drop of NIGROSINE near one end of slide 2. Transfer BACILLUS MEGATERIUM into drop (do not smear with loop) 3. Use another slide to spread stain 4. Let air dry 5. View under microscope
Making an Endospore Stain
1. Tiny loop full of water 2. Transfer both BACILLUS MEGATERIUM into water and smear with loop 3. Air dry, heat fix, let cool 4. Place slide on hot plate (including weigh boat and paper towel square on smear) 5. For 3-5 minutes, continuously keep the paper towel square saturated with MALACHITE GREEN while the slide gently heats 6. Remove from heat and place on staining rack to cool 7. Tilt one end and rinse with water bottle (decolorizer) 8. With slide on staining rack, flood smear with SAFRANIN for 30 seconds (rinse with water bottle) 9. Gently blot dry and view under microscope OIL IMMERSION
Making Acid-Fast Stain
1. Tiny loop full of water 2. Transfer both STAPH EPIDERMIS and MYCOBACTERIUM CHROMOGENICUM into water and smear with loop 3. Air dry, heat fix, let cool 4. Place slide on hot plate (including weigh boat and paper towel square on smear) 5. For 5 minutes, continuously keep the paper towel square saturated a bright pink color with CARBOFUCHSIN (+) while the slide gently heats 6. Remove from heat and place on staining rack to cool 7. Tilt one end and rinse with water bottle 8. With slide on staining rack, flood smear with ACID ALCOHOL decolorizer for 3-5 minutes (rinse with water bottle) 9. Flood smear with METHYLENE BLUE (+) for 30 seconds (rinse with water bottle) 10. Gently blot dry and view under microscope OIL IMMERSION
Making a Simple Stain (+)
1. Tiny loop full of water on slide 2. Transfer BACILLUS MEGATERIUM into water and smear with loop 3. Air dry, HEAT FIX, let cool 4. Flood smear with METHYLENE BLUE and let sit for 1 minute 5. Tilt one end and rinse with water bottle 6. Blot dry and view under microscope
Making a Gram Stain
1. Tiny loop full of water on slide 2. Transfer both STAPH EPIDERMIS and E. COLI into water and smear with loop 3. Air dry, heat fix, let cool. 4. With slide on staining rack, flood smear with CRYSTAL VIOLET (+) and let sit for 20 seconds 5. Tilt one end and rinse with water bottle 6. Flood smear with mordant Gram's IODINE and let sit for 1 minute (rinse with water bottle) 8. Flood smear with 95% ALCOHOL decolorizer and let sit for 10 seconds (rinse with water bottle) 10. Flood smear with SAFRANIN (+) and let sit for 20 seconds (rinse with water bottle) 11. Blot dry 12. View under microscope OIL IMMERSION
What are the 2 problems that occur with increasing magnification?
1. need for greater resolving power 2. decreasing image brightness
Capsule Stain
1.) negative stain with congo red 2.) air dry- don't heat fix 3.) Hydrochloric acid 4.) Safranin counter stain
How would a total dilution of 1:10,000,000 be prepared?
1/10 X 1/10 X 1/10 X 1/10 X 1/10 X 1/10 X 1/10
How would a total dilution of 1:2 X 10^4 be prepared?
1/20 X 1/10 X 1/10 X 1/10
What are the two reagents for VP test?
10 drops of a-naphthol and 10 drops of KOH
How soon can a nitrate test be read after the addition of the reagents?
10 minutes
If IgM is present...what does this mean?
1st response - recent infection
1. Salmonella 2. Shigella
2 medically significant Enterobacteriae
If IgG is present...what does this mean?
2nd response - past infection
1. Mannitol (carb) 2. NaCl (Sodium chloride/salt) 3. Phenol red pH indicator
3 ingredients in Mannitol/Salt agar
What solution is used for the Catalase test?
3% H2O2 solution (hydrogen peroxide)
Normal % of monocytes?
3-7%
at what temperature are cultures incubated in he detection of fecal coliforms
35C
1. Divide plate into thirds 2. Obtain swab of bacteria 3. Streak bacteria in zig zag in section one. 3. Drag from section one and zig zag in section two at 90 degree angle 4. Drag from section two and zig zag in section three at 90 degree angle from section 2.
4 Steps of Streak plate
Protozoan Movement
4 common types of movement = 1. pseudopodia- false feet allows members of Sarcodina (Endamoeba) class to extend protoplasm 2. flagella- long whip-like appendages that all members of class Mastigophora possess (Trichomonas) 3. cilia- short stiff bristle-like structures; members of the class Ciliata (Balantidium) 4. undulating membranes- Apicomplexa (Sporozoa); thin and undulate back and forth along one side; several members of Mastigophora (Trypanosoma)
Mnemonic: C CUT 1. Carbohydrate fermentation tests 2. Cytochrome Oxidase 3. Urease 4. TSI tests
4 tests frequently used to differentiate Gram negative bacteria.
What range should the rheostat be between so that the background of the image is white?
4-6
What total magnification is the high dry objective? What is the color of the ring?
400X/Blue
What total magnification is the scanner objective? What is the color of the ring?
40X/red
1. Prepare smear/heat fix 2. Cover with crystal violet (1 minute), rinse (distilled water) 3. Iodine mordant for 1 minute, rinse 4. Gram decolorizer (aprox 5-10 seconds), rinse 5. Gram safranin (30 sec), rinse and dry.
5 Steps of a Gram stain
BA - enriched with?
5% sheep's blood
neutrophil
55-90% phagocytes & killers of bacteria suggest cuts infections
AMC BOB 1. Amylase 2. Mannitol Salt 3. Catalase 4. Bacitracin 5. Optochin 6. Blood hemolysis
6 Tests commonly run on Gram positive bacteria
Phenol Red is yellow below what pH?
6.8
Phenol red is yellow below what pH?
6.8
Bromthymol blue is green at what pH?
6.9
How soon can the VP test be read after adding reagent?
60 minutes
What is the diameter of the lymphocytes?
7-18 micrometers
How big is a red blood cell? what can be seen by the naked eye?
7.5 microns/100 microns
MSA agar selective agent
7.5% salt-Sodium Chloride
Bromthymol blue is blue at what pH?
7.6
oil refractive index _______ glass refractive index (<,>,=)
=
The organism on this plate is resistant to Erythromycin.
??
Facultative anaerobe, negative ***Escherichia coli and Enterobacter aerogenes fit the description
A coliform is defined as a ______ that ferments lactose to produce gas, and it is gram _____. Which 2 baterica fits this description?
Station 11 Parasitic worms Description of disease
A disease of carnivorous mammals that infect the muscle
What are the color changes for Methyl Red?
Acid=red Neutral=orange Alkaline=yellow
What is the color changes for Citrate test?
Acid=yellow Neutral=green Alkaline=Blue
What are the color changes for phenol red during Carbohydrate Fermentation?
Acid=yellow Neutral=red-orange alkaline=cherry red
What turns the MacConkey agar red?
Acids from lactose fermentation
Station 12 Starch test Reagents added after incubation
Add indole to plate, stain starch after growth
Catalase is an enzyme found in:
Aerobes, facultative aerobes, microaerobes
Triple Sugar Iron (TSI)
Agar that contains dextrose, lactose, sucrose, phenol red for pH, and an iron indicator change in an agar slant.
Purpose of the Condenser Lens on Brightfield Microscope
Aims light through the specimen.
transmission of contagious diseases
Air droplets, direct contact with respiratory secretions or body fluids, through contact with contaminated inanimate objects
In experimentation why is it impossible to have an obligate anaerobe?
Although a THIO tube can provide 0% oxygen at the bottom of the tube, there is no way to innoculate the bacteria into the tube without exposing it to oxygen. Oxygen is present everywhere in the lab and oxygen is toxic to obigate anaerobe
Urease positive organisms will hydrolyze urea into:
Ammonia
What is the nitrogen source in Simmons citrate medium?
Ammonium dihydrogen phosphate
a. does not occur in the United States b. causes river blindness c. is transmitted by a biological vector d. *none of the above*
Amoebiasis: a. does not occur in the United States b. causes river blindness c. is transmitted by a biological vector d. none of the above
Station 12 Starch test Enzyme
Amylase
Bacteria secretes________ (enzyme) which breaks down______.
Amylase; starch
What is an oxygen requirement test and what is it made of?
An oxygen requirement test tests a microorganism on their need for oxygen. This determines if a microorganism needs oxygen to live, if oxygen is toxic to them or if it doesn't matter. It is made up of thioglycolate and methyene blue.
Bacillus anthracis
Anthrax
Antimicrobial produced by some molds and bacteria are generally called.
Antibiotics
Why would it be important to know the identity of a pathogen before prescribing an antibiotic?
Antibiotics are specific to certain bacterias; some organisms may be resistant to a certain antibiotic but others may be sensitive. Also, knowing the identity can allow the doctor to find the MIC and prescribe the right dosage to the patient so resistance doesn't occur.
Direct ELISA test for ....
Antigen
Station 10 Parasitic worms Location in humans
Any tissue in the body
Non-coliforms
Are Salmonella and Shigella coliforms or non-coliforms?
No
Are coliform bacteria usually pathogenic?
Yes
Are non-coliform bacteria usually pathogenic?
Station 10 Parasitic worms Stage passed to humans
Ate undercooked beef or pork.
What are two genera of endospore forming bacteria that are medically important?
Bacillus and Clostridium
Spore stain
Bacillus subtilis or Clostridium botulism
What is a spore-producing organism?
Bacillus subtilus
Streptococcus pneumoniae
Bacitracin resistant/ Optochin Sensitive bacteria
Streptococcus pyogenes
Bacitracin sensitive/ Optochin resistant bacteria
What is the difference between bacteria and eukaryotic microbes under a microscope?
Bacteria are significantly smaller and lack visible internal structures
E. coli
Bacteria that appears metallic green in color on EMB agar due to acid production
clear
Bacteria that do not ferment lactose on EMB agar appear ______
Alpha-hemolytic
Bacteria that do not make hemolysin, but do secrete chemicals that turn red blood cells a green color
Dark
Bacteria that ferment lactose on Eosin Methylene Blue (EMB) agar create colonies that appear ________
Staphylococcus aureus
Bacteria that is positive (turns agar yellow) in Mannitol/Salt agar test
what is a smear?
Bacteria that is spread on a slide and allowed to dry
Metallic green
Bacteria that produce a large amount of acid appear _________ on EMB agar.
Why is staining required to see bacterial cells
Bacterial cells are translucent. Staining is required so bacterial cells are visible under the microscope
What happens in the proccess of gelatin hydrolysis?
Bacterial species release proteases in the medium and "digest" the gelatin, so it is no linger to keep it's solid form and turns into a liquid.
This large protozoan is actually a good probiotic agent when consumed with yogurt and cheese and helps with digestion.
Balantidium coli
VP (Voges-Proskauer) test : Negative MR suggests that VP test may be performed in second tube . The reagents used for the VP test are
Barritt's reagent A&B . When these reagents are added to a broth in which acetyl methyl carbinol is present, they turn a PINK-BURGANDY color (a POSITIVE VP test).
tania sps.
Beef tape worm
blood agar with s. aureus
Beta hemolysis surrounding colonies. presumptive for s. aureus
Streptococci Group A & B
Beta hemolytic (complete destruction of red blood cells)
What does the amp resistance gene release?
Beta lactamase -hydrolyzes certain antibiotics
The Bacitracin test is used to differentiate:
Beta-hemolytic Strep. pyogenes and resistant vs. susceptible organisms
A dull green color; ***** Salmonella typhi produces a black or very dark brown color
Bismuth Sulfide Agar (BSA) test
Name some examples of epidemics
Black plague, smallpox, HIV/AIDS, ebola, influenza
Hydrogen Sulfide Production "Triple Sugar Iron Agar" positive result
Black precipitation
Fluroquinolones
Block DNA synthesis Ex: Ciprofloxacin
MR-VP TEST Theory : **MR-VP (Methyl Red- Voges-Proskauer)BROTH**media contains GLUCOSE and PEPTONE. All enterics oxidize glucose for energy; however the end products vary depending on bacterial enzymes.
Both the MR and VP tests are used to determine what end products result when the test organism DEGRADES GLUCOSE.
The Coagulase Slide test detects:
Bound coagulase
The Coagulase Tube test detects:
Bound or free coagulase
Differential for lactose/sucrose fermentation: **Lactose/ sucrose fermenting organisms = produce yellow/green colonies and turn surronding media yellow/green **Non - lactose/ sucrose fermenting organisms = produce opaque red/ pink/ white colonies and turn the surrounding media red
Brilliant Green Agar (BGA) test
pH indicators and respective medium and color produce?
Brom cresol Purple; Decaboxyl test; Purple @alkaline pH & yellow @acid pH
Name of pH indicator and its color at low and high/neutral pH for Snyfer test?
Brom cresol Purple; Neutral/high-green low/acid pH-- Yellow
pH indicators and respective medium and color produce?
Brom thymol Blue; Simmons Citrate Agar = Green @ neutral pH & Blue @ acid pH
pH indicator for Snyder test
Bromcresol green
What is the pH indicator of the Simmons Citrate Agar?
Bromothymol blue
What is the pH indicator for OF Glucose?
Bromthymol Blue
Station 9 Citrate test pH indicator
Bromthymol blue
What is a liquid medium called?
Broth
Station 6 Catalase test Positive result:
Bubbles.
Yeast produce by
Budding and fission
how are gram negative bacteria recolorized?
By using a counter stain (safranin, a red dye)
Describe how you would get the image in focus under oil immersion if you cannot see it the first time.
Bypass high dry, go back to low power, find object and focus. Go back to oil, add light, then find focus and it should be there.
C-I-A-S 1-1-5-1 P-S-D-C
C- Crystal Violet- 1 min -P- Primary stain I- Iodine- 1 min- S- Secondary Stain or mordant A- Acetone Alcohol- 5 sec- D- Decolorizer S-Safranin- 1 min- C-Counterstain
C-A- G-1-1 P-D-C ---------acid fast
C-carbolfuchsin Until Green Primary stain A- acid/Alcohol 1 min Decolorizer M- methylene Blue 1 min counter-stain
Glucose + Lactose + H2S + ????
Identify this KIA tube
Phenol red, Glucose, Lactose
In KIA test; Glucose and lactose fermentation is determined using a pH indicator ---------- which begins red and will turn yellow in the butt of the tube if ---------- is fermented and will cause the slant to turn yellow if ---------- is able to be fermented.
Source of infection
Index case
What is the reagent used for Oxidase?
Kovac's Oxidase
Candida
Little red clusters of berries
Chondrus crispus
Looks like sour kraut!
Paragonimus
Lung Fluke
MAC
MacConkey Agar
Vivax
Malaria
The substrate in MSA is:
Mannitol (carbohydrate)
MSA
Mannitol Salt Agar
MSA stands for:
Mannitol Salt Agar
PHENOL RED FERMENTATION TEST
Media : 0.5 % Glucose solution or 0.5% Mannitol broth with indicator phenol red . Procedure : broth is inoculated with test bacteria and incubated at 98F /37C For 24 hours and color noted.
Stab and Streak
Method used to perform a TSI agar test
MH
Mueller-Hinton agar plate
Station 17 Yeast and Molds What is the study of molds and yeast is called?
Mycology.
What are the results of MacConkey agar?
No Growth, Gram +, Lactose Unknown Growth, Gram -, Lactose - Growth, Gram + Lactose +
How do negative stains work?
Normally stains are positively charged and therefore attracted to the negatively charged bacteria. In a negative stain, the dye is negative and therefore repelled by the bacteria and the dye stains the surroundings/background
Station 1 Gelatin test Media
Nutrient gelatin (straw colored media/ purple cap)
Total Magnification
Ocular lens magnification (10) X objective lense magnification
Shigella
On SS Agar, which bacteria produces a colorless colony?
What does the VP test detect?
Organisms capable of fermenting glucose
What occurs in α-hemolysis?
Partial destruction of RBCs
MAC agar - NLF examples
Pathogens - Salmonella/Shigella "non coliform"
Streptococcus Pneumoniae
Pneumonia
In a Coagulase Slide test, clumping indicates:
Positive
In a SIM test, growth radiating out from the stab line indicates:
Positive motility
Antibody
Protein secreted by B lymphocytes
Penicillium
Purple branch with fingers
Trichomonas vaginalis
Purple dots WITH FLAGELLA!
What do both coagulase tests utilize?
Rabbit plasma (with anticoagulant)
Station 14 TSIA Forth tube
Red slant / Black butt - Glucose fermentation and sulfur reduction
+ Resistance
Resistant
What is an endospore?
Resting body formed by certain bacteria in response to harsh conditions that allows the bacteria to survive, not for reproduction
Station 16 Malaria Stage of development
Ring stage
Salmonella Typhi
Salmonella
Is MSA selective, differential, or enriched?
Selective due to sodium chloride Differential for S. aureus - fermentation
- Resistance
Sensitive
Citrate Utilization - agar?
Simmons Citrate Agar
Rhizopus
Spaghetti and Meatballs
Presumptive Test
Specific test for the detection of coliforms Lactose fermantation test (development of gas/acid is indicative of a coliform) MPN test gives idea of number of coliforms present
Staphylococcus Aureus
Staph infections, Toxic shock syndrome, Skin infections, MRSA
What organisms grow on MSA?
Staphylococci
Positive (clusters)
Staphylococcus tests __________ for Catalase, Nitrogen Reduction, and Arrangement tests
Staphylococcus epidermis
Staphylococcus that tests negative for Mannitol, Coagulase, DNase is what?
Staphylococcus aureus
Staphylococcus that tests positive for Mannitol, Coagulase, DNase is what?
Station 9 Citrate test Negative result:
Stays green/ usually no growth.
Hemolysin produced by Streptococci
Streptolysin O & Streptolysin S
Hemolysins produced by streptococci are called:
Streptolysins
Shigella
T-I-U for Shigella •TSI: Red/Yellow (lac-/glu+) •Indole ring in SIM Deep: Negative •Urease test: Negative •MacConkey Agar: COLORLESS bacause LACTOSE (-) Neg.
What are two important diseases caused by acid fast bacteria?
TB and Leprosy Mycobacterium tuberculosis and Mycobacterium leprae
Clostridium Tetani
Tetanus
Their only Carbon source
The Citrate test is used to detect bacteria that use citrate for this reason
Parfocal
The ability to change between lenses and still stay in focus
What is a titer?
The amount of antibodies in a serum
What does the MR test detect?
Organisms capable of performing mixed acid fermentation
CITRATE TEST THEORY
Organisms that UTILIZE CITRATE for energy produce ALKALINE compounds as by-products. Thus, a POSITIVE RESULT for citrate utilization is the formation of a BLUE color.
Brilliant Green Lactose Bile does what?
Oxgall and brilliant green are selective by inhibiting gram +. Lactose is differential ingredient.
E. coli
Oxidase negative bacteria example
Pseudomonas aeruginosa
Oxidase positive bacteria example
What is the effect of H2O2 on the cell?
Oxidizer
What is the purpose of mixing the reagents and the broth in the VP test?
Oxygenates the medium
When an epidemic becomes worldwide
Pandemic
These body lice are only annoying because they mess up our clothing.
Pediculus
What provides the protein in MR/VP broth?
Peptone
What is the pH indicator for Carbohydrate Fermentation?
Phenol Red
**Selects staphylococcus species since they can survive high salt concentrations ***Organisms capable of using mannitol as a food source will produce acidic byproducts of fermentation that will lower the pH of the media. The acidity of the media will cause the pH indicator, phenol red, to turn yellow *****Staphylococcus aureus is capable of fermenting mannitol (yellow) while Staphylococcus epidermidis is not (will remain red)
Phenol Red Mannitol Salt Agar (MSA)
Station 5 Urease test pH indicator
Phenol red
What is the pH indicator in TSIA?
Phenol red
PHENOL RED FERMENTATION TEST theory
Phenol red broth is a test medium to which a carbohydrate like glucose or mannitol is added . Phenol red is red under nuetral pH but tends to turn yellow under acidic condition. Acid production from fermentation of the sugar lowers the pH and medium turns yellow indicating carbohydrate utilization by the bacteria . (A) Gas production also from fermentation can be detected as a bubble in an Inverted Durham's tube inside the broth. (AG)
Major Groups of Antiseptics and Disinfectants
Phenolic compounds Alcohols Halogens Heavy metals Surface-active agents Acids/Alkali Ethylene Oxide B-propiolactone Basic dyes
Ascaris
Pig roundworm
Gram Stain
Pink = gram - purple = gram +
What color is Gram -?
Pink/fuchsia/colorless
Enterobius vermicularis
Pinworm (Dead Bean)
Station 16 Malaria Causative organism genus
Plamodium
This parasite can be transmitted by the Anopheles mosquito.
Plasmodium falciparum, malariae, & vivax
What was the control plate in this UV experiment?
Plate with lid
Station 10 Parasitic worms Phylum
Platyhelminthes
A blue result in a citrate test indicates:
Positive
A darkened medium in a Bile Esculin Test indicates:
Positive
A liquid result for a gelatin test indicates:
Positive
A red result for VP indicates:
Positive
A red result for the MR test indicates:
Positive
Bubbles present in a catalase test indicate:
Positive
In a Coagulase Tube test, a solid medium indicates:
Positive
Dark blue color on an oxidase test is indicative of:
Positive (Cytochrome c oxidase present)
In a SIM test, blackening of the medium indicates:
Positive (sulfur reduction)
A pink result for a urea test indicates:
Positive (urease)
Citrate Test
Positive organism= E.coli Positive color results= Blue Indicator= bromthymol blue carbon source= Sodium citrate nitrogen source= ammonium dihydrogen phosphate
Station 8 Methyl Red test Pick the positive tube
Positive result: Red in color, means : glucose was broken down into various acid products
Interpretation and Potential bacteria for Urea
Positive-Proteus-instense pink; E. coli-yellow-Negative
What resists color changes in the MR/VP tube?
Potassium phosphate
What does the oxidase test detect:
Presence of cytochrome c oxidase
What does a gelatin hydrolysis test detect?
Presence of gelatinases
Gram Stain - 3 stains
Primary - crystal violet Mordant - Iodine Counterstain - Safranin
Acid
Product of carbohydrate fermentation
How does blackening of the medium occur?
Production of H2S gas combines with iron, to make ferric sulfide (FeS) which is a black precipitate
Positive ***Proteus contains cystein desulfurase enzyme that produces H2S in the presence of iron salts (also noted in KIA and SIM test)
Proteus is H2S (Hydrogen sulfide test) positive or negative?
Postive on the Urea test
Proteus is Urease positve or negative?
Causes of malaria
Protozoan plasmodium species
These organism are typically oxidase positive:
Pseudomonadaceae
Pseudomonas
Pseudomonas gives NEGATIVE Voges Proskauer Indole and Methyl red tests, but a POSITIVE catalase = Liberation of Bubbles and oxidase test = Blue purple color
Most resistant bacterium:
Pseudomonas; Serratia may also be very resistant
After culturing, my unknown bacteria on a HEA agar in an incubated 37 degrees celsius and no growth
Pseudomopheda Floresess
Saccharomyces
Purple Honeycomb
What color is present when starch has been not been hydrolyzed? is is + or -?
Purple and it is starch hydrolysis (-)
What color is Gram +?
Purplish/red
Breaks down urea to ammonia and CO2
Purpose of urease enzyme
What is the mode of UV for microbial killing?
Pyrimidine Dimer
A slide from Chronic Lymphocytic Lukemia patient would contain what two cells?
RBC (Erythrocytes) and Lymphocytes
Iodine
Reagent for amylase test
Hydrogen peroxide
Reagent for catalase test
Kovak's reagent
Reagent for cytochrome oxidase test
Phenol Red is what color between 6.9 and 7.3?
Red
Station 4 Nitrate test Important
Red before zinc - positive Colorless after zinc - positive Red after zinc - negative
Station 4 Nitrate test Positive result :
Red color after A and B- have nitrate in the tube If colorless add zinc after all 3 steps, if still colorless its positive.
Station 4 Nitrate test Negative result:
Red color after adding zinc
Station 14 TSIA Fifth tube
Red slant / Black butt - Glucose fermentation and sulfur reduction
Station 14 TSIA First Tube
Red slant/yellow butt, and agar lifted - Glucose fermentation with acid production. Proteins catabolized aerobically (in the slant) with alkaline products (reversion), also produced gas
Station 2 Phenol Red media Positive result:
Red/Pink - no carbohydrate fermentation was used but proteins were used to grow
Station 3 Indole test Positive result:
Red/pink ring at the top, means that the bacteria produced tryptophanase and breakdown the substrate tryptophan, one being indole.
4 Lenses Magnification
Red: scanning (4x) Yellow: low power (10x) Blue: high power (40x) White: oil immersion (100x)
Purpose of the Diaphragm Adjustment Lever on Brightfield Microscope
Regulates the amount of light passing through the specimen.
The continual source of infection
Reservoir
Hydrogen Sulfide Test
SIM agar -- semi soft to detect motility Tube C is positive for H₂S production
On this medium Salmonella usually produces a black colony, Shigella a colorless colony & all lactose positive colonies appear red
SS Agar test
Hydrogen Sulfide Production "Triple Sugar Iron Agar) Bacteria
Salmonella & Proteus
SS Agar
Salmonella produces a black colony on which medium?
Bismuth Sulfide Agar (BSA)
Salmonella typhi produces a black or very dark brown color in which test medium?
Epidemiology
Science that deals with when and where diseases occur and how they are transmitted
Epidemiologist
Scientist that complies the data and tries to locate the source of the infection
Is Bile Esculin Agar selective, differential, or enriched?
Selective due to bile Differential for enterococci and Strep. bovis
Is MacConkey agar selective, differential, or enriched?
Selective due to bile salts and crystal violet Differential for lactose fermenters
Is Eosin Methylene Blue agar selective, differential, or enriched?
Selective due to dyes Differential for lactose fermenters
MacConkey Agar
Selective for detection and isolation of gram (-) organisms and differential for gram negative enteric bacilli Inhibits growth of staphylococcus, enterococcus, and streptococcus
Great inhibition zone
Sensitive
When doing Antibiotic Susceptibility test what inoculation tool and technique is used?
Serile swab/Bacterial Lawn
DNase agar - positive test example?
Serratia marcescens
Fasciola hepatica
Sheep liver fluke
Shigella Dysenteriae
Shigellosis
Beta hemolytic organisms
Show complete hemolysis, giving a clear zone with a clean edge around the colony **pathogenic
Alpha hemolytic organisms
Show incomplete hemolysis, producing methemaglobin and a green, cloudy zone around the colony
Gamma hemolytic organisms
Show no hemolysis and no change in the blood agar around the colony occurs
CITRATE TEST media
Simmon's Citrate agar slants contain sodium citrate (the only carbon source) and ammonium ion (the sole nitrogen source). A pH indicator, Bromothymol Blue is also included. Bromothymol Blue is GREEN at pH < 7.0 and BLUE at pH > 7.6.
Station 9 Citrate test Media
Simmons Citrate (green slant/navy Cap)
Medium used for Snyder test
Snyder test medium
What is the source of sulfur in a SIM medium?
Sodium thiosulfate
Which media gives the best isolation and is easiest to see if contamination has occured?
Solid media
Station 9 Citrate test Principle
Some bacterias can use citrate as its only source of carbon, some cannot.
Escherichia coli
Some microorganisms like _________, produce a metallic green sheen on Eosin Methylene Blue (EMB) test.
Hydrogen Sulfide Production "Triple Sugar Iron Agar" inocculation procedure
Stab/Streak
•G+ cocci •on BAP media--colony morphology: MEDIUM sized WHITE colonies; NO hemolysis •Microscopic Morphology: staph = clusters •part of normal flora on human skin •LOVES prosthetic devices •opportunistic pathogen •catalase + •coagulase -
Staphyloccocus epidermidis Colonies are circular, convex with an entire margin.
boils are caused by
Staphyloccus aureus
**Same is MSA Mannitol test but lacks phenol red indicator. **Selects for Staphylococcus and allows for development of natural colony pigment formation unlike in MSA
Staphylococcus 110 Medium test
What gram positive bacteria would result in a positive catalase test and as well as having bright yellow colonies in a mannitol salt agar
Staphylococcus Aureus
DNase agar - negative test example?
Staphylococcus aureus
The Coagulase Test is used to differentiate?
Staphylococcus aureus
What organism ferments mannitol?
Staphylococcus aureus
Gelatin Deep- visual reaction results
Staphylococcus aureus - Liquefied Positive Serratia Marcescens - Positive Bacillus Cereus - Positive Micrococcus roseus - Solid Negative Micrococcus luteus - Negative Bacillus subtilis - Negative Escherichia Coli - Negative Enterobacter aerogenes - Negative Proteus vulgaris - Negative
•Staphyle = clusters ("grape-like clusters") •Large golden colonies •Creamy appearence on plate •Narrow beta-hemolysis zone around colonies
Staphylococcus aureus:
BA - gamma hemolysis example
Staphylococcus epidermis "normal flora"
CATALASE TEST
Staphylococcus, Micrococcus and most aerobic organisms produce catalase Streptococcus and most anaerobic bacteria are UNABLE to produce it.
Station 12 Starch test Substrate
Starch
Station 12 Starch test Media
Starch plate
1. Use swab to fill 3/4 of plate 2. Turn plate 1/4 turn, turn swab, repeat fill 3. Turn plate another 1/4 turn, turn swab, repeat fill
Steps of making a spread plate
What technique is used to encourage streptolysin activity on a blood agar plate?
Streak-stab Technique
CATALACE what organism is beta hemolytic pattern (clear)?
Strep
Streptococcus pyogenes
Strep throat, scarlet fever, rheumatic fever
What Gram-positive organisms are catalase negative?
Streptococcus
Gram negative, cocci
Streptococcus and Staphylococcus are both gram ______ and as shaped as _______.
BA - incomplete hemolysis example
Streptococcus pneumonia
The Optochin test is used to differentiate:
Streptococcus pneumoniae
What's Optochin sensitive?
Streptococcus pneumoniae
BA - complete hemolysis example
Streptococcus pyogenes -Strep Throat
scarlet fever is caused by
Streptococcus pyrogenes
Alpha and beta
Streptococcus shows what type of hemolysis?
Negative (chains)
Streptococcus tests __________ for Catalase, Nitrogen Reduction, and Arrangement tests
Streptococcus pneumoniae
Streptococcus that causes alpha hemolysis in blood agar is what?
Streptococcus pyogenes
Streptococcus that causes beta hemolysis in blood agar is what?
-gain entrance to body as result of trauma to skin -most are common soil inhabitants which enter skin through splinters, thorns, or sphagnum moss -example: Sporothrix schenckii
Subcutaneous Mycoses
Mannitol
Sugar in Mannitol/Salt agar
Lactose
Sugar source in EMB agar
What is the biochemical reaction for sugar fermentation?
Sugar---------------------> acid with/without gas
In a TSIA slant, blackening of the medium indicates:
Sulfur reduction
In a TSIA slant, a yellow slant/black butt indicates:
Sulfur reduction and glucose and lactose/sucrose fermentation
In a TSIA slant, a red slant/black butt indicates:
Sulfur reduction and glucose fermentation
How is ferrous sulfide produced in the hydrogen sulfide production test?
Sulfur-containing amino acids (already in the tube) are broken down into hydrogen sulfide and mixed with iron sulfate (already in the tube) to produce ferrous sulfide
When doing Antibiotic Susceptibility test what observation are made in Lab and what reported out to physicians?
Susceptibility & Resistance
In a Bacitracin test, a zone of clearing greater than 10 mm indicates:
Susceptible
In a Novobiocin test, a zone of clearing greater than 16 mm indicates:
Susceptible
In an Optochin test, a zone of clearing greater than 14 mm indicates:
Susceptible
Proteus
T-I-U for Proteus spp. •TSI: Red/Black (lac-/glu+/H2S+) •Indole: depends on species--p. vulgaris (+); p. mirabilis (-) •Urease: Strong Positive that results in magenta color •MC: COLORLESS because lac- •PUTRID, terrible, NASTY smell
•TSI: Red/Black (Slight yellow in the bottom of butt) (lac-/glu+/H2S+) •Indole: Negative •Urease: Negative •MC: COLORLESS because lac- •Hektoen Enteric Agar: Black precipitate, reaction between ferric ammonium citrate and H2S produced from SULFUR reaction
T-I-U for Salmonella:
In lab 5 (identifying an unknown), which mediums needed to be innolculated with a needle?
THIO tube, SIM tube and gelatin
Station 10 Parasitic worms Genus
Taenia
Station 10 Parasitic worms Species of pork tapeworm
Taenia Sollium
Station 10 Parasitic worms Species of beef tapeworm
Taenia saqinata
These worms possess a head end called a scolex and reproductive units called proglottids.
Taenia solium & saginata (platyhelminthes; cestodes)---tapeworms
•Indicates the ability of the bacteria to produce the enzyme urease, which converts urea → NH3 (ammonia) + CO2 •Color change due to pH change (alkaline) •Yellow (acidic) to Rose (alkaline) or Magenta (alkaline) •Strength of pink color is dependent upon how much ammonia is produced
Test #3-Urease Test:
Confirmed Test
Test that requires EMB media (selective for gram neg) Coliform colonies are metallic green
Bacitracin & Optochin (could also use hemolysis/blood agar)
Test used to differentiate between Streptococcus pyogenes and Strep. pneumoniae
Completed Test
Test where colony is inoculated into lactose broth A gram stain is also prepared -Tubes with lactose + and gas/acid further confirm presence of coliform bacteria -gram (-) bacilli
catalase test
Tests for catalase enzyme. adding H2O2 to culture results in Bubble formation = positive. negative = no bubble formation
Acid Fast Stain
Tests for mycolic acid. Carbolfushin is a lipid soluble stain, and thus penetrates. Counter stain with methylene blue.
Streptococcus pyogenes
The McKesson Strep A dipstick test is a rapid chromatographic immunoassay for the detection of Strep A antigen. What bacteria does this test identify?
Gram Negative Enterics
The Methyl Red/Voges-Proskauer Test differentiates between these types of bacteria
Streptococcus mitis
The bacteria on this plate are called?
Streptococcus salivarius Sucrose into glucose and fructose Tongue
The bacteria on this plate are called? What do they breakdown? Where are they found?
Streptococcus mutans Ferment fructose into lactic acid Teeth
The bacteria on this plate are called? What do they ferment? Where are they found?
Penicillin
The bacterial species on this plate have been incubated with antibiotic disks. Which antibiotic is the bacteria least sensitive (most resistant) to?
Ciprofloxacin
The bacterial species on this plate have been incubated with antibiotic disks. Which antibiotic is the bacteria most sensitive (least resistant) to?
Diameter of field
The distance across the entire visible field when looking through the ocular lenses.
Dinoflagellates
The little monster
Minimum Inhibitory Concentration (MIC)
The lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism (creates a zone of inhibition)
Purpose of Course Adjustment Knob on Brightfield Microscope
The main focusing tool.
a. are all members of the animal kingdom b. only cause respiratory diseases c. are all unicellular d. *are commonly classified on the basis of their sexual spore formation*
The mycotic agents: a. are all members of the animal kingdom b. only cause respiratory diseases c. are all unicellular d. are commonly classified on the basis of their sexual spore formation
How does a halo form in the starch hydrolysis test?
The presence of amylase will decompose starch into glucose molecules. Iodine only reacts with starch to make it a brown color. So, if amylase is present and breaks down all the starch, a yellow halo will appear
Transformation
The process by which competent bacterial cells take a DNA to form recombinant DNA
INDOLE RING TEST procedure
The test organism is inoculated into tryptone broth, a rich source of the amino acid tryptophan. Indole POSITIVE bacteria such as ESCHERICHIA COLI produce tryptophanase, an enzyme that cleaves tryptophan, producing indole and other products. Tubes are incubated at 98F/37C for 24 -48 hours .
why are agar plates used when observing microorganims?
They provide a large surface area for the ease in observing or retrieving many individual colonies
What is the point in observing untreated ("time zero") plates in an experiment where you're observing the effective powers of heat and UV light treatments?
They serve as a control to compare the other times to.
Why is thioglycolate used in an oxygen requirement test?
Thioglycolate eats up oxygen, so it creates a gradient in which oygen is about 21% at the top of the tube and 0% at the bottom.
Enterococcus It is not a coliform MacConkey Agar
This agar is negative for what? Why? What agar is it?
Proteus It is not a coliform MacConkey Agar
This agar is negative for what? Why?What agar is it?
E. coli CHROMagar
This agar is positive for what? What agar is it?
Enterococcus CHROMagar
This agar is positive for what? What agar is it?
Klebsiella CHROMagar
This agar is positive for what? What agar is it?
Proteus CHROMagar
This agar is positive for what? What agar is it?
E. coli It is a coliform MacConkey Agar
This agar is positive for what? Why? What agar is it?
Klebsiella It is a coliform MacConkey Agar
This agar is positive for what? Why? What agar is it?
Entamoeba histolytica
This amoeba may contaminate food or water and cause a form of dysentery.
Bacillus cereus
This microbe forms gram-positive rods. Endospores may be visible in older cultures as clear areas inside the cells. Older cultures may stain pink, due to the deterioration of cell walls.
Aspergillus Species
This mold may contaminate peanut butter, peanuts, rice, and grains.
AB-
This person has what type of blood?
B-
This person has what type of blood?
O+
This person has what type of blood?
Claviceps purpurea
This wheat rust is actually good to eat in cereal along with blue berries and sugar.
Candida albicans
This yeast can affect bartenders and dishwashers and cause an inflamed skin infection.
Canida abicons
Thrush and moniliasis (vaginal yeast infections)
why is the disk-diffusion method used?
To determine the effectiveness of some antibiotics on certain bacteria
What's the purpose of the HardyCHROM Biplate Experiment (Hurbi)?
To diagnose a urinary tract infection & isolate/differentiate bacteria with in the urine.
Function of immersion oil
To reduce scattering of light which improves resolution
What is the purpose of an inverted Durham tube?
To trap a portion of any gas produced
Pregnant women should avoid cleaning out the kitty litter box to avoid contact with this parasite.
Toxoplasma gondii
This bug actually transmits parasites by biting the victim and then depositing the parasites in its fecal matter into the bite wound.
Triatomid Bug
Station 11 Parasitic worms Genus
Trichinella
This worm causes a sexually transmitted disease.
Trichomonas vaginalis
This parasite causes a vaginitis that can be treated with metronidazole.
Trichomoniasis vaginalis
Station 11 Parasitic worms Species
Trichonoma Spiralis
These worms can be sautéed up in butter and served with meat balls along with a good Chianti wine.
Trichuris trichiura
TSIA stands for:
Triple Sugar Iron Agar
True/False: Bilharzia is a major world health problem because many lakes and streams are infested with the flukes that cause this disease.
True
True/False: Diagnosis of intestinal parasites can often be done following an O&P check.
True
True/False: Humans can be exposed to Histoplasmosis because it affects birds and chickens.
True
True/False: Metronidazole can be used as a treatment for many intestinal protozoan infections.
True
True/False: The Mastigophora exhibit a method of movement with flagella.
True
True/False: The disk diffusion method (Kirby Bauer) is one of the most common methods for the determination of antibiotic sensitivity of bacteria.
True
True/False: The most common treatment for tapeworm infections would be niclosamide.
True
True/False: Trypanosoma cruzi causes Chagas disease which occurs in Central and South America.
True
False
True/False: All fungi are classified on the basis of their asexual means of reproduction.
True
True/False: Special culture media is required to grow the fungi and yeast because they grow slower than bacteria.
This parasite occurs most commonly in Africa and is transmitted by a tsetse fly.
Trypansoma brucei gambiense & brucei rhodesiense
Station 3 Indole test Substrate
Tryptophan
What must be present for the production of indole?
Tryptophan
Indole Test
Tryptophan ----> Tryptophanase ----> Pyruvate
Station 3 Indole test Enzyme
Tryptophanase
Urea production: Negative result, Positive result, media used
Tube remains a peach color, tube turns hot pink (ammonia production), urea broth
Mycobacterium Tuberculosis
Tuberculosis
Beta-hemolytic
Type of bacteria that make hemolysin
Selective and Differential
Type of media Eosin Methylene Blue (EMB) agar is
Differential
Type of media Hemolysis/blood agar test is
Phenol red
Type of pH indicator in Mannitol/Salt agar
Mannitol Salt agar, Yellow = +, Staphylococcus aureas = +
Type of test? Color that = positive result? Example positive
Amylase Test. Clear + positive.
Type of test? What indicates a positive result?
Cytochrome Oxidase Test. B is +.
Type of test? What is positive?
Simmons Citrate, B = +
Type of test? Which tube is +?
Urease test. Right tube (Pink) = +.
Type of test? Which tube is +?
Obligate aerobes, Facultative anaerobes
Types of bacteria that produce catalase
what happens to DNA when UV light is exposed?
UV light changes DNA that result in mutations in living organisms. these induced mutations can cause cell death.
Station 11 Parasitic worms Stage passed to humans
Undercooked meat containing juvenile nurse cell eaten
Urease Test
Urea ----> Urease ----> Ammonia
pH indicators and respective medium and color produce?
Urea Broth; Phenol Red; Intense pink
What nutrients are found in urea broth?
Urea and yeast extract (trace)
Station 5 Urease test What is the product that turns it a pretty pink?
Urea hydrolysis produces ammonia, which raises the pH in the medium and turns the pH indictor pink.
coarse adjustment knob
Used for focusing with 4x and 10x objective lenses
Methyl Red Test
Used to differentiate between E. coli and E. aerogenes pH indicator detects concentration of acid end products (+) red pH 4 -- E. coli (-) yellow pH 6 -- E. erogenous
Negative Staining (general)
Uses acidic (-) stain which colors the background and not the cells. -would use in Cerebrospinal fluid specimens to look for fungi)
Simple Staining (general)
Uses one basic (+) stain which colors cells
Differential Staining (general)
Uses two different colored basic stains which helps differentiate between types of cells.
What Reagent is used for MRVP? What is the pH indicator?
VP Reagent A , VP Reagent B Methyl Red
What's Optochin resistant?
Viradans: Streptococcus mutants
Hemolysis
Virulence factor of some bacteria that aids in differentiating types of Gram + bacteria on blood agar
Red tube = +. Acetoin & 2,3 butandiol
Voges-Proskaeur test. Which one is positive? For what is it positive?
What are we doing to the E.coli bacteria in the transformation experiment?
We are making the bacteria competent by making the negative bacteria accept DNA which is negative
UV-A-longest UV-B-medium length UV-C-shortest
What 3 groups does ultraviolet light divide into?
Neutrophil Granulocytes that are the first response to defend against bacterial and fungal infections
What WBC is this? What is its function?
Basophil Granulocyte that is important allergic** and parasitic resposnes
What WBC is this? What is their function?
Eosinophil Granulocytes that destroy parasitic worms, also involved in allergic responses
What WBC is this? What is their function?
Lymphocyte Initiate the immune response
What WBC is this? What is their function?
Monocyte Phagocytes that remove debris, phagocytose pathogens
What WBC is this? What is their function?
anti-B
What antibodies would agglutinate this antigen?
Intestinal bacteria that are gram (-), non-spore-forming bacilli that ferment lactose to acid and gas
What are coliform bacteria?
Part of normal flora Lactose fermenters Gram negative
What are coliforms?
Gram (+), non-spore-forming bacilli that do not ferment lactose to acid and gas
What are non-coliform bacteria?
Lactose non fermenter Not part of normal flora
What are some characteristics of enteric true pathogens?
Fermenting lactose or sucrose Enteric coliform
What are the bacteria doing on this plate? What organisms are growing on this plate?
They are not fermenting lactose or sucrose Non-coliform
What are the bacteria doing on this plate? What organisms are growing on this plate?
- gram negative - normal enteric flora - do not ferment lactose - opportunistic infections
What are the characteristics of NonColiform bacteria?
Proteus
What are the colonies surrounded by the brown halo on this plate called?
Blue = oxygen, white = NO oxygen.
What are the colors inside the anaerobic jar indicating?
Sexual contact, transfer of infected blood, infected needles, breast milk, during labor.
What are the modes of transmission of HIV?
Ingestion Inhalation Direct contact Animal bite Blood transfusion Sexual contact Sick people or animals Carriers of disease (animal or human) Contaminated food, water, objects Aerosols
What are the modes of transmission of infectious diseases?
E. coli
What are the red colonies shown on this plate called?
Klebsiella
What are the steel-blue colonies on this plate called?
Flu-like for 2-4 weeks, then asymptomatic for 10 yrs. Fevers & sweats from infections, weight loss.
What are the symptoms of HIV?
Enterococcus
What are the turquoise colonies on this plate called?
Staphylococcus epidermidis
What are the white colonies on this MSA plate?
Micrococcus luteus
What are the yellow colonies on this MSA plate?
Staphylococcus aureus
What are the yellow colonies on this MSA plate?
Do not rinse and do not heat fix
What are two things you should NOT do when doing Negative staining?
Formation of ammonia when bacteria ferments citrate
What causes that bromothymol blue to turn blue in a citrate test?
Alkaline pH of ammonia
What causes the pink color in urease agar?
Red, opaque colonies
What color do coliforms grow as on the MacConkey and CHROMagar?
Acidic- dark blue colonies with a metallic green sheen Less acidic- pink colonies
What color do fermented bacteria become on EMB agar?
Colorless
What color do non-fermented bacteria become on EMB agar?
Translucent colonies
What color do non-lactose fermenters grow as?
Dark colonies with a metallic green sheen OR pink
What color does E. coli and Klebsiella produce on EMB plate?
Clear
What color does Proteus and Enterococcus produce on EMB?
Pink
What color is gram negative?
Purple
What color is gram positive?
Toxin A and B antigen produced by Clostridium difficile
What did we test for using indirect ELISA?
Serum antibodies in blood against HIV.
What do both ELISA & Western blot detect?
Distort bacteria DNA, inhibit replication and transcription.
What do these pyrimidine dimers do to DNA?
Means to retain the dye when challenged by a decolorizer.
What does "fastness" mean in terms of acid fast staining.
AIDS-Acquired Immunodeficiency Syndrome
What does HIV cause?
Protein A present only in staph. Staph aureus gives clumping aka agglutination.
What does Ig G bind to?
A second antibody is added which binds to the serum antibody against HIV. A chromogen is added to bind to the antibodies added resulting in coloring, coloring shows a positive result.
What does a positive HIV result for ELISA show?
Fibrinogen & Ig G
What does the Catalase test use?
Lactose Fermentation only
What does the EMB plate assess?
CD4 T helper cells causing them to drop
What does the HIV virus attack?
Assess H2S production & Lactose fermentation of gram- enteric bacteria.
What does the Hektoen agar assess?
Bacterial cell wall synthesis
What does the Optochin disk inhibit?
Chemical pack and water
What does the anaerobic jar have inside?
New covalent bonds between adjacent pyrimidines (c-c, t-t, c-t), aka pyrimidine dimers.
What does the energy in UV light form?
Staphylococcus Aureus Causes yellow color due to fermentation of manitol. pH=6.8
What gram positive bacteria is growing on this Manitol media and why?
She will produce antibodies against Rh which will cross the placenta during the 3rd trimester. They will attack the fetus, causing a miscarriage (usually only with the second pregnancy)
What happens if a pregnant woman is Rh (-) while her baby is Rh (+)?
Impetigo, Cellulitis, abscess, boils, furuncle, food poisoning, toxic shock syndrome, septicemia.
What illnesses are caused by Staph Aureus?
Sepsis, scarlet fever, Rheumatic Fever, Necrotizing Fasciitis, Toxic Shock Syndrome, septicemia, nephritis
What illnesses are caused by Streptococcus species?
Methyl red
What indicator does the Voges-Proskauer test use?
Dyes
What ingredient in Eosin Methylene Blue (EMB) inhibits the growth of Gram Positive bacteria?
To differentiate organisms that may infect the urinary tract E. coli- red colonies Klebsiella- steel blue colonies Enterecoccus- turquoise colonies Proteus- brown halo
What is CHROMagar used to determine?
Whether or not bacteria ferment lactose to acid and gas
What is EMB and MacConkey Agar used to determine?
Grows with or without O2 Detoxify toxic O2 byproducts.
What is a facultative anaerobe?
Fomite may be defined as an inanimate item that could transfer microbial organisms. Ex: a fork
What is a fomite?
Requires small O2 amount Detoxifies O2 byproducts Does not grow in atmospheric O2
What is a microaerophile?
Can't live in oxygen Can't detoxify byproducts of O2.
What is an anaerobe?
The study of causes, occurrence, transmission, distribution & prevention of disease
What is epidemiology?
Masses of bacterial cells, dextran, and food debris
What is plaque?
Transmission from person to person
What is propagated transmission?
Differentiating between Staph Aureus and Staph Epidermis.
What is the Catalase test used for?
Detecting HIV, Enzyme Linked Immunoabsorbant Assay
What is the ELISA test used for?
Identifying enteric bacteria
What is the Enterotube test used for?
High O2 at top decreasing to little O2 on bottom.
What is the O2 gradient on the test tube used to grow these organisms?
Incidence: Number of newly infected people Prevalence: Number of infected people alive.
What is the difference between incidence rate and prevalence?
HIV proteins separated by size, transferred to a membrane, then serum antibodies, conjugate and chromogen are added, positive = spots
What is the difference in the process of ELISA vs. Western blot?
# of new cases at specific time/ population at risk multiplied by K
What is the formula for Incidence rate?
# of existing cases at specific time/total population multiplied by K
What is the formula for prevalence?
Remove O2 and maintain complete anaerobic atmosphere inside
What is the function of the anaerobic jar?
The largest clear zone where the microorganism was inhibited.
What is the minimum inhibitory concentration?
Index case
What is the name for the first detected case?
Balantidium coli
What is the name of this organism?
1:32
What is the patients titer?
Chemical pack reacts with Water pack to make anaerobic condition.
What is the process occurring in the anaerobic jar?
1:4
What is the result for this test?
Coccidioides immitis; spherules
What is this organism and feature?
Giardia intestinalis; cyst
What is this organism and phase?
Entamoeba histolytica
What is this organism?
Enterobius vermicularis
What is this organism?
Enterobius vermicularis; as an adult pinworm
What is this organism?
Necator americanus
What is this organism?
Trichinella spiralis
What is this organism?
Trichomonas vaginalis
What is this organism?
Entamoeba; cyst
What is this organism? Phase?
Entamoeba; trophozoite
What is this organism? Stage?
Gel Immunoprecipitation
What is this test used for?
A type of electromagnetic energy
What is ultraviolet light?
Combination of positive results in a 5 digit numeric code.
What is used to identify the microorganism?
BBL Enterotube II result sheet
What is used to score the results of the Enterotube II test
Gram negative cannot grow due to 7.5% Sodium Chloride.
What kind of bacteria cannot grow in Manitol media?
Selective media for growing gram negative bacteria specifically. Inhibit gram + bacteria growth due to bile salts & dyes.
What kind of media are EMB & Hektoen?
Lentivirus
What kind of virus is HIV?
Litmus milk
What media is this?
N. Broth
What media is this?
N. gelatin
What media is this?
N.A. deep
What media is this?
N.A. slant
What media is this?
Manitol & Sheep blood agar
What media is used to grow gram+ bacteria?
Mannitol salt & Sheep blood agar
What media was used to isolate gram + bacteria?
EMB, Blood agar, Sabouraud
What media were used for the Urine streak?
Fluid Thiogycollate medium (test tube broth)
What medium was used to observe bacteria's reaction to O2?
Enterotube test.
What method is used to differentiate between enteric gram- bacteria?
Kirby-Bauer method
What method is used to test antimicrobial effectiveness?
E. coli Enterobacter Staph. Epidermis Staph. Aureus Strep Pyogenes Candida
What microorganisms were isolated using the Urine streak?
Irreversible damage, cause bacterial death
What occurs after bacteria is exposed to UV-C light for 2 min?
Symptoms appear CD4 T helper cells drop Body becomes susceptible to opportunistic infections
What occurs in the AIDS stage of HIV?
The virus presents no symptoms
What occurs in the latent period of HIV?
Some growth due to DNA polymerase I reversing and repairing damage.
What occurs to bacteria exposed to UV-C light for 30 sec?
No change
What occurs to bacteria with no exposure to UV-C light?
Becomes inactivated when exposed to air. Reduces O2 concentration, increases CO2 concentration
What occurs to the BD gas pack?
Proteus or Salmonella Black color due to production of H2S precipitate
What organisms could be on this Hektoen media and why?
Anaerobic Jar
What other tool is used to see the organism's reaction to O2?
Mitis Salivarius Agar Contains crystal violet and potassium tellurite to inhibit gram (-) bacilli
What plate is this? What does it contain?
-apply wound and skin isolation techniques -wash hands carefully to avoid possible transmission
What precautions should be taken for a patient hospitalized with a superficial mycosis?
-active cases may require strict isolation -masks are required -hands washed -and reduce all potential chances of airborne transmission
What precautions should be taken for a patient hospitalized with a systemic lung mycosis?
B
What proteins would this person have on his/her red blood cells?
Circle
What shape is cocci?
Rod
What shape is rod?
Agglutination test Staph Aureus is positive for agglutination. Staph Epidermis is negative for agglutination
What tests differentiates between Staph Aureus and Staph Epidermis?
Gram negative rod
What type of bacteria is this classified as?
Gram positive cocci
What type of bacteria is this classified as?
Alpha hemolysis
What type of hemolysis is shown?
Beta hemolysis
What type of hemolysis is shown?
Gamma
What type of hemolysis is shown?
Alpha
What type of hemolytic reaction is this?
Beta
What type of hemolytic reaction is this?
Gamma
What type of hemolytic reaction is this?
Anaerobe Grows at the bottom of test tube, where there is no O2.
What type of organism is growing in this test tube?
Microaerophile Growth in the middle of test tube. Does not grow in high O2 or no O2.
What type of organism is growing on this tube?
Sheep Blood Agar
What type of plate is this?
Alpha hemolysis, E. coli or Strep. Pneumoniae
What type of reaction? Possible bacteria this could be?
Beta hemolysis, Streptococcus pyogenes
What type of reaction? Possible bacteria this could be?
-Filobasidielliosis (Cryptococcosis) = tissue biopsy -Athletes foot = skin samples -Tinea capitis = skin samples; hair; use Wood's lamp -Pneumocystis pneumonia = lung biopsy (sputum sample)
What type of specimen should be collected when testing for: -Filobasidielliosis (Cryptococcosis) -Athlete's Foot -Tinea capitis -Pneumocystis pneumonia
Lactose, sucrose, dextrose tests. Middle is negative.
What type of tests and which tube(s) has/have negative result?
Staphylococcus aureus, streptococcus pyogenes, clostridium botulinum and tetani
What types of organisms present beta hemolysis?
when are semi-solid mediums typically used?
When observing the motility of a bacteria because they can easily move and "swim" through the soft medium
Symbiosis
When organisms live in close association with us
What does parfocal mean?
When you have the object in focus with one objective. It will be visible on all objectives with just a minor adjustment from the fine adjustment knob
In the intestine
Where are enteric bacteria commonly found?
A source that infects many people at once
Where does an epidemic usually originate from?
Skin Yes they are pathogenic because they produce beta hemolysis and those bacteria are pathogenic
Where does the bacteria come from that are cultured on these plates? Are the bacteria pathogenic? Why/why not?
E. coli, Enterobacter, Salmonella, Proteus
Which 5 bacteria are identified using the Enterotube?
Proteus
Which NonColiform organism was studied in class?
Lysine Lactose Urea
Which Substances in the Enterotube will be observed for positive results?
UV-C-highest energy, damages bacteria DNA, exposure for a few minutes leads to death.
Which UV light is used to kill bacteria?
Clostridium
Which anaerobe was studied in class?
E.coli and Enterobacter
Which are the two coliform bacteria studied in class?
E. coli Enterobacter Staph. aureus Staph. e.
Which bacteria can be grown on Sabouraud?
Strep. pyogenes
Which bacteria does not grow on Sabouraud?
E.coli uses it, aka photo-reactivation.
Which bacteria forms light repair?
E. coli Enterobacter Staph. aureus Staph. Epidermidis Candida
Which bacteria will grow on the sheep blood agar?
Pneumocystis Carinii Kaposi's sarcoma
Which diseases were discovered in 1981 due to AIDS that our body is normally resistant to?
E.coli & Enterobacter
Which enteric bacteria are non pathogenic i.e. coliforms?
Proteus
Which enteric bacteria are opportunistic pathogens?
Salmonella & Shigella
Which enteric bacteria are true pathogens?
Proteus, Salmonella, Shigella. No color on EMB due to being lactose non fermenters.
Which enteric organisms could be in this EMB media and why?
DNA Photolyase
Which enzyme is used in photo-reactivation?
E. coli
Which facultative anaerobe was studied in class?
Streptococcus Pyogenes
Which gram positive bacteria is responsive to Bacitracin or A disc antibiotic?
Staphylococcus Epidermis Does not ferment Manitol due to 7.4 pH
Which gram positive organism is in this Manitol media and why?
Staph Aureus or Streptococcus Pyogenes Complete hemolysis (beta)
Which gram positive organisms could be on this blood media and why?
E. coli Enterobactor Proteus Salmonella Shigella
Which gram- Enteric bacteria were studied in class?
E.coli has a green metallic sheen Vigorous lactose fermentor
Which gram- enteric bacteria is seen on this EMB agar?
Enterobacter Has a pink color due to lactose fermentation
Which gram- enteric bacteria is seen on this EMB plate?
Micrococcus luteus
Which microaerophilic organism was studied in class?
Streptococcus pneumonia, Enterobacter, E. coli Picture shows Alpha aka partial hemolysis.
Which organism could be growing on this blood agar and why?
Staphylococcus epidermis or Candida Gamma hemolysis-does not hemolyse blood
Which organism is on this blood agar media and why?
Enterobactor or E.coli Pink to orange color due to lactose fermentation.
Which organisms could this be in this Hektoen media and why?
Saroubaud
Which plate is used to grow Candida sp?
Enterobacter
Which specific bacteria is (VP) vouges paskauer positive?
Salmonella, Shigella
Which were the gram+ enteric true pathogens studied in class?
Hydrogen sulfide is produced as a by-product of aerobic respiration in some bacteria because instead of having O2 as the ultimate electron acceptor, they use sulfur
Why is some TSI agar black?
Describe two ways in which smear preparation differs when using a stock brother as opposed to using a stock slant culture.
With broth you must use 5 drops of the broth itself and smear across the whole slide, With the slant you must prepare with 1/2 a drop of water first, add the bacteria and the smear across the whole slide, let both dry
What stains are used in differential blood cells counts?
Wrights or Giemsa stain
These are commonly called fleas and could transmit diseases such as the black plague.
Xenopsylla cheopis
Gram Staining
YOU MAY SEE: -gram negative Bacilli; pink rods -gram negative Cocci; pink cocci -gram positive Cocci; purple cocci -gram positive Bacilli; purple rods -gram stain of mixed culture
Escherichia
_________ is methyl red (MR) postive since it produces drastic amounts of acid, lowering the pH and causing the methyl red to remain red.
define turbid
a cloudiness in a liquid medium caused by cell growth
What is the definition of an infectious disease?
a disease caused by microorganisms that enter the body and multiply in the tissues
Christensen's urea Broth
a media containing urea, among other ingredients and a pH indicator called phenol red, the byproduct of urease can be detected.
What is the Kirby-Bauer agar method?
a method most commonly used to determine the effectiveness of an antibiotic. Antibiotic is added to a plate of a microorganism to create a zone of inhibition. Large zone= sensitive microorganism. Small zone= resistant microorganism. This test is RELATIVE
What is a Durham Tube?
a small glass tube places upside down in the big culture tube
how do antibiotics work?
a specific mechanism targets some vital process of the specific bacteria to cause death
what is UV light used as?
a sterilizing agent
define colony
a visible mound of millions of a bacteria's descendants, all arising from one cell
The tsetse fly: a. can transmit African sleeping sickness b. can transmit malaria c. usually acts as a mechanical vector d. deposits eggs called nits in the victims hair
a. *can transmit African sleeping sickness* b. can transmit malaria c. usually acts as a mechanical vector d. deposits eggs called nits in the victims hair
The antibiotic dispensing unit: a. dispenses antibiotic soaked disks onto plates covered with bacteria b. dispenses five disks at a time c. can be used to perform dilution streak plate techniques d. all of above are true
a. *dispenses antibiotic soaked disks onto plates covered with bacteria* b. dispenses five disks at a time c. can be used to perform dilution streak plate techniques d. all of above are true
Echinococcus granulosis: a. forms hydatid cysts around the body b. has the shape of cocci in clusters c. is treated with antifungal medicine d. is a name I made up
a. *forms hydatid cysts around the body* b. has the shape of cocci in clusters c. is treated with antifungal medicine d. is a name I made up
Mississippi River Valley fever is usually caused by: a. Candida b. Histoplasma c. Taenia d. Mississippi River Mud
a. Candida b. *Histoplasma* c. Taenia d. Mississippi River Mud
A mycotoxicoses could be caused by: a. Pneumocystis carinii b. Coccidiodes immitis c. Aspergillus flavus d. ringworm
a. Pneumocystis carinii b. Coccidiodes immitis c. *Aspergillus flavus* d. ringworm
Which of the following would be a good treatment for roundworm infections: a. Quinine b. metronidazole c. amphotericin B d. mebendazole
a. Quinine b. metronidazole c. amphotericin B d. *mebendazole*
Most intestinal protozoan parasite diseases are best tested by studying: a. blood samples b. stool samples c. throat swab d. urine samples
a. blood samples b. *stool samples* c. throat swab d. urine samples
Infections caused by Trichomonas vaginalis: a. can be treated with quinine derivatives b. are usually sexually transmitted c. are always fatal d. only affect women
a. can be treated with quinine derivatives b. *are usually sexually transmitted* c. are always fatal d. only affect women
Which of the following is not true concerning the nematode life cycle? a. eggs are consumed in contaminated food or water b. eggs hatch into tiny larvae that eventually gain access to the lungs c. larvae are coughed up, swallowed and end up in the intestines where they develop into adults d. the adults are picked up by biological vectors and transmitted to a new host
a. eggs are consumed in contaminated food or water b. eggs hatch into tiny larvae that eventually gain access to the lungs c. larvae are coughed up, swallowed and end up in the intestines where they develop into adults d. *the adults are picked up by biological vectors and transmitted to a new host*
A good example of a mechanical vector would be: a. hard tick b. cockroach c. body louse d. mosquito
a. hard tick b. *cockroach* c. body louse d. mosquito
Chagas disease: a. is a disease I made up b. is common in the desert southwest of the United States c. affects the skin and mucous membranes causing a severe rash d. can be transmitted by the bite of a "kissing" bug
a. is a disease I made up b. is common in the desert southwest of the United States c. affects the skin and mucous membranes causing a severe rash d. *can be transmitted by the bite of a "kissing" bug*
Rat fleas could transmit: a. malaria b. Rocky Mountain spotted fever c. elephantiasis d. scabies e. none of these
a. malaria b. Rocky Mountain spotted fever c. elephantiasis d. scabies e. *none of these*
Cercaria and miracidia are related to: a. protozoans b. yeast c. roundworms d. flukes
a. protozoans b. yeast c. roundworms d. *flukes*
The Platyhelminthes would include all the following except: a. tapeworms b. flatworms c. ringworms d. flukes
a. tapeworms b. flatworms c. *ringworms* d. flukes
Trophozoites refer to: a. the resistant cyst structure made by protozoans b. a class of highly motile protozoans c. deadly flesh eating parasites d. free-living forms of protozoans
a. the resistant cyst structure made by protozoans b. a class of highly motile protozoans c. deadly flesh eating parasites d. *free-living forms of protozoans*
In the Kirby Bauer test, sensitivities to various antibiotics are determined by: a. the streak plate technique b. using unpaid volunteers c. using a metric stick d. growing the bacteria in broth tubes
a. the streak plate technique b. using unpaid volunteers c. *using a metric stick* d. growing the bacteria in broth tubes
With the hard ticks: a. they usually burrow into the skin and cause intense itching b they can exhibit transovarian transmission c. they have six legs, jaws, and antennae d. they only invade the pubic areas
a. they usually burrow into the skin and cause intense itching b *they can exhibit transovarian transmission* c. they have six legs, jaws, and antennae d. they only invade the pubic areas
Phenylalanine Deamination "Phenylaline Agar" - purpose?
ability of an organim to deaminate phenylalanine resulting in the production of phenylpyruvic acid and ammonia (NH3) - enzyme used is phenylalanase
Carbohydrate Fermentation Test - purpose?
ability of an organism to ferment a specific carbohydrate with or without the production of gas
Tryptophan Hydrolysis "Indole Test" - purpose?
ability of organism to split indole from the amino acid tryptophan using tryptophanase
Voges-Proskauer "MR-VP Broth" - detects what product?
acetoin
Decolorizer
acetone/alcohol 5 seconds
What is used in the decolorzation step of an acid fast stain?
acid alcohol
Which cells retain the primary stain in an acid fast stain?
acid-fast bacteria retain the carbolfuchsin dye because their cell walls contain mycolic acid (lipid) which retains the dye
Is yogurt acidic or alkaline
acidic, makes lactic acid
Culturing
act of growing
eosinophil
active in worm or fungal infections allergies & inflammatory response.
Voges-Proskauer -"MR-VP Broth" - once incubated what needs to happen?
add 18 drops each of Barritt's solution A and B
Methyl Red Test "MR-VP Broth" - After incubation what do you do?
add 3-4 drops of Methyl Red Reagent
rh typing
add anti-D to the samples. if there is agglutination within 2 minutes this is rh positive. no agglutination, rh negative. after the first pregnancy if the mother is rh negative, anti-rh antibodies can attack the fetus
Epidemic diseases
affect many individuals in population in short time
What does an iris diaphragm do?
affects contrast between the light and dark parts of the specimen,
When is the mordant (gram's iodine) added in gram staining?
after Crystal Violet is applied
Tryptophan Hydrolysis "Indole Test" - procedure?
after incubation is complete add 10 drops of Kovacs Reagent
what is a solid medium called?
agar
Motility Test - contents?
agar and TTC
PEA agar with blood
agar only
blood agar
agar only
chocolate agar
agar only
TSA agar
agar only (yellow)
What enzyme is linked with the antibodies?
alkaline phosphatase
define streaming
all objects "flow" with the movement of water
semisolid medium (deeps)
allow bacteria to grow down in the medium where there is less oxygen than at the surface. deeps allow for the detection of motility by growth away from initial inoculation site.
differential media
allow colonies to be different colors based off of some characteristics
how would you explain the purpose of blood in the blood agar medium
allows detection of hemolysis reaction
Differential medium
allows for growth of all bacteria while differentiating them from one another
Selective medium
allows the growth of certain bacteria while preventing growth of other bacteria
what would a green reaction code for
alpha
Viridans & Strep. pneumoniae
alpha hemolytic (incomplete/ greenish color)
If milk is pasteurized, what causes it to spoil in such a short time?
although pasteurized, there are still live bacteria present in the sample
How does oxygen affect the growth of bacteria?
amount of oxygen present in an environment can be vital to growth of bacteria.
What is catalase?
an enzyme breaks down H2O2
What is catalase?
an extracellular enzyme produced by some bacteria in order to detoxify Hydrogen Peroxide (H2O2).
DNAse is:
an extracellular enzyme that is produced within the cell and secreted outside of the cell wall
agar
an extract from marine red algae
vector
an organism, a biting insect or tick, transmits a disease or parasite from one animal or plant to another.
What type of environment will allow nitratase be used?
anaerobic conditions so the organism can derives its oxygen from nitrate
B anthracis causes what disease?
anthrax
B cells produce what in the body?
antibodies
known what molecules are on the latex beads that specifically detect s. aureus
antibody a
type AB blood has
antigen A & B and no antibodies agglutination in both A & B
type a blood has
antigen A, and B antibodies agglutination occurs when anti-A serum is added
type b blood has
antigen B, and A antibodies if agglutination occurs when anti-B serum is added
What is a chemotherapeutic agent/antibiotic?
antimicrobial compounds that can be safely absorbed or taken internally
Antigen
any substance that produces an immune response in the body.
What is ARA?
arabinose -promoter that activates GFP and Amp resistance genes
what is the plasmid in the Biorad kit
arabinose used to turn "on" the glow portion of this plasmid. this plasmid contains the ampicillin resistance cassette and a gene for a green fluorescence protein (GFP). once expressed the GFP will fluoresce under UV light. If bacteria have taken up the plasmid, the colonies should fluoresce green under UV light
Microscope diaphragm
attached to bottom of stage allows control of amount of light that will pass through the slide.
What is the most effective form of sterilization?
autoclaving
What is aseptic technique?
avoiding contaminants, preventing infection
What are fermenters?
bacteria can utilize glucose in the presence or absence of O2
What is a vegetative cell?
bacteria cells that are metabolizing and reproducing rapidly
halophile
bacteria that grow better in environments with high salt concentrations
MacConkey Agar (MAC) - differential
bacterial colonies that can ferment lactose turn the medium any variation of red. the red color is due to the pH indicators response to acidic environment created by fermenting lactose. organisms that do not ferment lactose do not cause a color change
If the chemical is killing the bacteria it is said to be....
bactericidal
If the chemical is inhibiting the bacteria growth it is said to be...
bacteriostatic
how is the relationship established between the organism and the legume
bacterium binds to root hairs of the plant, sends out an infection thread that invades the deeper root tissue and forms a small tumor-like structure called a root nodule
basophil
bag of purple balls
What will be in high numbers if the patient has an active infection?
band - neutrophils
Immature neutrophils...AKA?
bands
basis of blood grouping
based on the surface antigens
Is ammonia acidic or basic?
basic
What are the least abundant WBCs in normal blood?
basophils
why are spores not easily stained, and why is heat applied?
because of their hardy nature, therefore, a heat must be applied so the stain can penetrate the spore.
why is detecting pathogens in water difficult
because they are present in such low numbers by the time they are detected it is usually too late to prevent an outbreak of disease.
why are hypertonic environments (higher osmotic pressure) often less tolerated by bacteria?
because water flows out of the cell, causing the cell to dry out.
no blood on the plate what reaction is that.
beta
MAC agar contents
bile salts neutral red lactose
MAC agar selective agent
bile salts - support gram negative
what are the detectable differences between bacteria?
biochemical in nature, and reflect different evolutionary paths. example one may use lactose but not glucose or may use glucose but not fructose. subtle differences are bacteria may use lactose as an energy source accomplished through different pathways, utilizing different sets of enzymes during the process.
Students do various biochemical tests and learn that bacteria has enzymes that can breakdown
biochemicals ( substrate ) and produce visible reactions that help to identify microrganisms
Hydrogen Sulfide Production "Triple Sugar Iron Agar" - positive test?
black precipitate along stab line
How is the Ferrous sulfide seen in the medium?
black precipitate in the medium
Stphylococcus aureus
boils and pimples
T cells are produced where in the body?
bone marrow
Clostridium and Bacillus cause what deadly diseases of humans?
botulism and tetanus
BHI
brain heart infusion agar
What is hydrolysis?
breakdown of starch
catalase enzyme
breaks down hydrogen peroxide to water and oxygen. needed for an enzyme to exist in the presence of oxygen.
if an organism is a fermenter what would you see in a macconkey agar plate
bright pink
eosinophil
bright red background
What is the pH indicator for Citrate test?
bromthymol blue
The methyl red (MR) and Voges-Proskauer (VP) tests are read from a single inoculated tube of MR-VP broth. After 24-48 hours of incubation the MR-VP
broth is split into two tubes. One tube is used for the MR test; the other is used for the VP test.
thioglycolate broth
broth used for oxygen requirement of bacterial growth
Voges-Proskauer "MR-VP Broth" - negative result?
brown color develops
Carbohydrate Fermentation Test - gas production positive test?
bubble forms in Durham tube
How is the number of viable bacteria determined?
by calculating the number of colony forming units per milliliter of sample. this is done by diluting the initial sample through serial dilutions.
how are antibiotics produced?
by microorganisms like fungi. In human and healthcare they are derived from microorganisms or are synthetically produced
facultative anaerobes
can grow with or without oxygen, but usually grow better in presence of oxygen
Describe a Capsular Stain (capsule)
capsule shape with a halo around it
What family of organic compounds does agar belong to?
carbohydrate
carbohydrate fermentation test
carbohydrates can be broken down by fermentation resulting in acid production. This test is used to determine the ability of an organism to ferment a specific carbohydrate with or without the production of gas, positive result=yellow color change with or without gas production. negative= no color change
What is the primary stain of an acid fast stain?
carbolfuchsin dye (red)
if a microbe can degrade hydrogen proxied what is the name of the enzyme that must be able to produce
catalase
What is the biochemical reaction for catalase test?
catalase H2O2 -------------------> 2H2O2 + O2
Negative MR (Methyl Red) BROTH test : Klebsiella and Enterobacter produce more neutral products from glucose (e.g. ethyl alcohol, acetyl methyl carbinol)
causing the pH to rise above 6.2. At this pH, methyl red indicator is a YELLOW COLOR (a).
what influences growth of bacteria?
chemical and physical factors. bacteria differ in in requirements for oxygen, temperature and osmotic pressure
growth medium (plural, media)
chemically defined or may contain partially digested proteins (peptones) or even more complex substances such as bovine red blood cells
define antiseptics
chemicals that are used on the skin or wounds to decrease the number of microorganisms
antibiotics
chemicals that have the ability to kill bacteria. often produced by microorganisms like fungi and are used as a defense mechanism
define disinfectants
chemicals used on inanimate objects
antiseptics
chemicals used on living tissue to kill microbes (ex/ mouthwash)
disinfectants
chemicals used on the surface of inanimate objects to kill microbes (ex/bleach)
What are spores resistant to?
chemicals, heating and basically all harsh conditions
What does chromagen do in the ELISA test?
chromagen will react with the enzyme and break down to show the blue color
zone of inhibition
circle around the disk where the antibiotic noticeably affect the cell viability. this is the area in which the effectiveness of antibiotic on bacterium is determined.
What shape is coccus/cocci?
circular/round dot like
What is the biochemical reaction for Citrate?
citrate ----------------> alkaline end product
Describe an Neutrophil cell
clear granules
DNase agar - postive test?
clear halo will appear around the areas where the DNase-producing organism has grown
How should the iris diaphragm be positioned fore low-power objective?
closed
What is the function of a platelet cell?
clotting
What is the biochemical reaction for coagulase test?
coagulase fibrinogen-----------------------> fibrin clot
What tests are needed to confirm Staph aureus?
coagulase, blood agar, and catalase.
psychrophile
cold - loving; optimum growth at 15 degree Celsius - 20 degree Celsius. commonly isolated from cold waters such as the bottom of the ocean. many grow well at temps of 0 degree Celsius - 4 degree Celsius (even below freezing in the presence of salt)
Mannitol Salt Agar (MSA)
common medium used for isolation of some pathogenic Gram positive organisms.
How does an epidemiologist decide wheather an epidemic really exists or not?
comparing the numbers of new cases with previous records
What is a phenol coefficient?
comparison of the killing action of the compund to that of phenol under the same conditions
beta
complete
What is beta hemolysis
complete hemolysis, is a complete lysis of red cells in the media around and under the colonies: the area appears lightened (yellow) and transparent.
state four factors that influence the size of inhibition
concentration of antimicrobial solubly
explain the pGLO positive gene regulation system
controlling the green fluorescent protein (GFP). the sugar arabinose turns the gfp gene on. also contained in the pGLO plasmid is the araC gene. When arabinose is taken up, it interacts with araC protein, which is bound to the DNA. This interaction causes araC to change shape, which helps RNA polymerase to bind to the Pbad promotor and transcribe the GFP gene. This enables the transformed cells to fluoresce green under ultraviolet light when arabinose is added to the nutrient agar.
complex media
culturing medium that contains nutrients released by partial digestion of yeast, beef, soy, or other proteins; thus, exact chemical composition is unknown
What's a BEA positive test?
dark brown
what is the appearance of fecal coliforms on mLES agar
dark colonies with a metallic sheen
What is the critical step of gram staining?
decolorizer is critical and the timing
this is mannitol salt agar, the s aureus, pathogenic, are able to ferment mannitol sugar and change color around bacterial colonies to a yellow halo
describe what is happening here and what medium
What's the purpose of Bile Esculin Azide agar test for?
detecting Enterococcus faecalis
multiple tube technique
detects coliforms involves two tests: presumptive test and confirmation test
oxidase test
detects presence of cytochrome oxidase involved in reduction of oxygen at end of E.T.C. this enzyme reacts with kovacs reagent creating a purple edging effect.= positive. negative = no edging effect
H2S production test
detects the enzyme that liberates hydrogen sulfide from a sulfur containing organic compound. demonstrates the production of hydrogen sulfide in Iron Peptone Agar. positive= growth with black precipitate in the media. negative= growth with no black precipitate
phenylalanine deamination test
detects the presence of phenylalanine deaminase which knocks off amine groups of molecules to form an acidic product. this test utilizes the amino acid phenylalanine that is converted to phenylpyruvic acid which is detected via a reaction with reagent FeCl3. positive= dark green color on slant. negative = no color change
What is the reason for coagulase test?
determine the ability of an organism to clot plasma by the action of the enzyme, coagulase
Hydrogen Sulfide Production "Triple Sugar Iron Agar" - purpose?
determine the ability of an organism to hydrolyze the sulfur containing cysteine to produce pyruvic acid, ammonia and hydrogen sulfide. -enzyme used: cysteine desufurase
What can B. cereus cause?
diarrhea
How can gram positive and gram negative bacteria be differentiated?
differences in their peptidoglycan layer
What property of bacterial cell structure makes the Gram Stain possible?
different in cell wall thicknesses
Is acid-fast stain simple or differential stain?
differential
Mannitol salt agar does what?
differential & selective media. differentiates pathogenic from not pathogenic.
DNase agar - purpose?
differential medium that tests the ability of an organism to produce an exoenzyme called DNase that hydrolyzes DNA
What is Blood Agar differential or selective?
differential, differentiates between those bacteria able to make the enzyme, hemolysis and those that cannot
differential stain
differentiates between two types of bacteria. visualizes the bacteria. example: gram stain
describe the Spread plate method
diltuing a bacteria sample before adding it to the agar so bacteria can be visualized easier and be counted more easily
describe the pour plate method
diluted cells are mixed with molten agar when it is still warm so that when it hardens into a solid, the microorganisms can grow inside and on top of the medium
Describe the streak plate method
diluting a bacteria enough on a certain area of an agar plate and spreading the bacteria out enough so that colonies can form
What is the dilution factor of the following dilutions: 1/100 X 1/10 X 1/10 X 1/10 X 1/10
dilution factor = 100,000
what did scientists start to notice as a lack of aseptic techniques?
directly related to incidences of fever and infection after childbirth, because students at the hospital would commonly go from the autopsy room to assist with delivery without washing hands.
Zoonoses
diseases of animals that can spread to humans
contagious (communicable) diseases
diseases transmitted person to person
What is the principle of technique for the Kirby-Bauer?
disk diffusion
hemolysis
done on SBA plates and recorded as alpha (partial sometimes with a greenish appearance), beta (complete) or gamma (none)
why do bacteria tolerate hypotonic environments?
due to the rigidity of the cell wall and the peptidoglycan layer
how do chemicals affect bacteria?
each chemical has a microbe that works most effectively against an environment which it works best in.
what does aseptic technique achieve?
enables pure cultures to be produced by keeping the culture free of contaminants. It also protects the microbiologist and the environment from the culture.
Coliform are what member of bateria?
enterobacteraciae (gram - / lactose fermenters)
what does ELISA stand for
enzyme-linked immunosorbent assay
hemolysins
enzymes that lyse host cells, especially red blood cells.
What increases with parasitic infections?
eosinophils
define Brownian motility
erratic vibration of a particle cause by the unequal collision of water molecules against it
Are red blood cells prokaryotic or eukaryotic?
eukaryotic
chemically defined media
exact chemical composition
what happens if you overheat the slide when heat-fixing?
excessive heat can destroy cells and make it impossible to identify
What are amylase, proteases and ureases all catagorized as?
exoenzymes
Gram's Iodine - mordant
facilitates further interactions between primary dye and cell wall. crystallizes dye that has penetrated the microbe
Vector of malaria
female anopheles mosquito
WALK AWAY PANEL if the sugar turns yellow?
ferments sugar (sucrose)
Hydrogen Sulfide Production "Triple Sugar Iron Agar" - contents?
ferrous salts that react with H2S to produce an insoluble black precipitate "sulfate"
know what molecules are on the surface of the bacteria that are detected by the latex beads
fibrinogen binds to clumping factor B
Why is serial diluting performed?
for plate counting and several techniques for isolating and maintaining pure cultures
Methyl Red Test "MR-VP Broth" - enzyme that breaks down formic acid?
formic hydrogen lyase
How does UV light kill organisms?
forms thymine dimers and prevents normal DNA replication
What is the function of a Eosinophil?
found in the blood due to parasites and allergies
sterile
free from bacteria or other living microorganisms; totally clean
enzymes
function to lower the activation energy of reactions that would otherwise be too costly in energy or too slow for successful growth of the bacteria. many bacteria need these enzymes to breakdown certain materials in the environment for energy requirements. if bacteria lost function of some enzymes they would no longer be able to survive in certain environments.
what does C. perfringens cause?
gas gangrene and perfringens food poisoning
Gelatin Liquéfaction test - positive test?
gelatin is liquefied
Gelatin Liquéfaction test - negative test?
gelatin is solid
what are the two parts of a scientific name?
genus and species or specific epithet
What is the biochemical reaction for OF Glucose Oxidizer?
glucose + O2 -------------------> acid end product
What is the biochemical reaction of OF Glucose Fermenters?
glucose --------------------> acid end product
What is the biochemical reaction for Methyl Red?
glucose ------------------>acid end product
What is the biochemical reaction for Voges-Proskauer?
glucose-----------------> neutral end product
ampicillinase
goes out into the environment and destroys the ampicillin in the media
A plate with a RESISTANT (no zone) Vancomycin would be gram + or gram -?
gram -
PLATE a Maconkey plate that has turned green, name the organism
gram -, oxidase +
EMB agar - selective
gram negative
BA - selective for?
gram positive
macconkey agar is inhibitory for gram negative and
gram positive
MSA agar - selects for?
gram positive because gram negative cannot grow in presences of salt
What does Staphylococcus look like
gram positive purple cocci in groups
What are the characteristics differential and selective media use to distinguish between various types of bacteria?
gram reaction, sugar fermentation, and tolerance of salt
what is the first and most important step in identifying bacteria?
gram staining
On a blood smear which is the Erythrocytes RBC?
gray color (background cells)
What color are spores when dyed?
green
Phenylalanine Deamination "Phenylaline Agar" - positive test?
green color develops
PGLO
green florescent Protein-GFP AMP function?- kill bacteria and select resistant population ARA function?- An inducer that causes bacteria to glow. which media glowed? LB/ARA/AMP
What is GFP?
green fluorescent protein -used an indicator of successful transformation and gene transcription
obligate aerobes
grow in presence of oxygen
obligate anaerobes
grow only in the total absence of oxygen
what does the Centers for Disease Control and Prevention state?
hand washing is the single most important procedure for preventing nosocomial infections (infections acquired in a hospital)
What does the coagulase enzyme do?
hardens a protective fibrin against phagocytes.
What does a condenser do on a compound microscope?
has a lens that gathers light and helps resolution.
thermophile
heat - loving; optimum growth at 50 degree Celsius - 60 degree Celsius (sometimes even higher). found in hot springs such as in Yellowstone
How does heat kill all organisms?
heat denatures their enzymes and inactivates them
what is a physical property of bacterial species?
heat sensitivity
What will allow the DNA "plasmid" to enter the E.coli?
heat shock "opens pores"
What are the two things to insure uptake of the gene
heat shock and calcium choloride
What are the ingredients used to make yogurt
heat, milk, cup, spoon, non-fat dry milk, culture, aluminum foil, incubator, glass rod for stirring
pasteurization
heating at 63 degree Celsius for 30 minutes or 72 degree Celsius for 15 minutes
What is the purpose of acid fast?
high cell wall content and to identify Mycobacterium and Nocardia
MSA - selective
high salt concentration of this medium inhibits the growth of most other organisms (halotolerant)
If positive test after 24 hours with Snyder test?
high susceptibility to dental caries
What is the effect of temperatures on bacterial growth?
high temperatures will kill bacteria while cold temperatures will inhibit their growth
the x40 ocular lens is also called?
high-dry objective
What shape does the monocyte nucleus have?
horseshoe shaped
dry heat
hot air, such as a hot oven. flaming inoculating loops is an example of a sterilization technique that uses dry heat.
carriers
human reservoirs that are infected without having symptoms
reservoirs
humans or animals that are sources of infection.
Station 1 Gelatin test Principle
if bacteria produces Gelatinase as they grow, they will breakdown the substrate which is gelatin.
Lymphocyte
immune reactions to foreign matter 20-35% 2nd place
moist heat
implies that steam is involved. example of sterilization techniques that uses moist heat are: boiling, autoclaving, and pasteurization. denatures proteins.
After medium is prepared how is it sterilized before use?
in a steam autoclave
why does water flow in or out of the cells?
in an attempt to make solute concentrations inside and outside the cell equal
Microbial biochemical characteristics are brought about by enzymatic reactions that are a part of specific metabolic pathways .The tests used
in this section were selected to illustrate process that leads to identification.
How does gram stain differentiate cells?
in two classes gram positive or gram negative based on the structure of the cell wall
fomites
inanimate objects such as surfaces, bedding, towels, pandemics drinking vessels, or needles.
polyenes, anti-fungal agent
includes amphtericin and Nystatin. binds to ergosterol component, results in a leaky membrane. it is very toxic, limited to use only in life threatening conditions. (Hint: POLY-many - combined - binding)
azoles, anti-fungal agent
includes clotrimazole, miconazole. inhibit ergosterol synthesis, without ergosterol the cell's membrane does not remain intact and the fungal cell dies. (Hint: a-against-inhibits ergosterol)
How are H2O2 molecules formed in a cell?
incomplete reduction
what is the result of higher solute concentration?
increase of osmotic pressure
urea hydrolysis
indicator= phenol red positive result color= pink positive organism= proteus vulgaris enzyme used= urease
how does temperature affect the growth of bacteria?
individual bacterial species usually grow over a range of temperatures. they have a temperature at which they grow best.
MacConkey Agar (MAC) - selective
inhibit growth of Gram-positive organisms allow for gram - negative to grow
How do you label test tubes and petri dishes?
initials-section # JHW-32 date 10-4-10 Medium BHA Organism/Bacteria E. coli
mechanical transmission
insect carries fecal pathogens on its feet and then walks on food
Urea Hydrolysis "Urea Broth" - positive test?
intense pink color
repair mechanism
involves enzymes which physically remove and replace the structural changes caused by radiant energy
Secondary stain
iodine/Gram -/1min/ Mordant
What do we use on a microscope to brighten an image?
iris diaphragm
Positive MR (Methyl Red- Voges-Proskauer) BROTH test : E. coli is one of the bacteria that produces acids, causing the pH to DROP below 4.4. When the reagent methyl red
is added to this acidic broth it will be cherry red
how can you determine if a microbe can degrade hydrogen proxied in a lab
it has to bubble
What does the term pasteurization mean?
it is a heating process designed to preserve the properties of the liquid but sufficient to kill any pathogens
Coarse adjustment knob?
it is used for bringing objects into initial focus with lower power objectives, never be used with high dry or oil
bacteriocidal vs. bacteriostatic
kills bacteris; temporarily inhibits bacterial growth
what sugar is the differential medium used to detect the presence of fecal coliforms
lactose
MacConky agar uses what biochemical reaction
lactose fermentation
macondky entric bacteria based on what biochemical reaction
lactose fermentation
What does strong fermentation of sugar produce?
large quantities of acid
Describe the gram positive peptidoglycan layer.
larger and more highly cross-linked containing small pores
Describe a yeast
larger than all other
What is another way in which media can be prepared?
liquid medium (media: broth), after incubation, liquid media will appear turbid due to bacterial growth this type of media is helpful when the bacteria need to be diluted.
Station 1 Gelatin test Positive result:
liquid, means that the bacteria produced Gelatinase as they grew, and broke down the substrate gelatin
what kind of bacteria are Clostrdium and Bacillus?
long gram-positive rods
the x10 ocular lens is also called?
low-power objective
give an example of a media that is both selective and differential
macconkey agar selects for gram negative and differentiates for lactose fermentation
bacterial genome
made up of the bacterial chromosome plus any plasmids that the organism may contain.
What is the function of the phospahte buffer for the urease test?
maintains ph
What is used to stain spores?
malachite green
Which dye is used to dye the actual endospore?
malachite green
MSA differential agent
mannitol and phenol red
What is the biochemical reaction for Mannitol Salt Agar?
mannitol----------------->acid end product
motility test
many organisms are motile because they possess flagella. flagella come in a variety of arrangements and can allow the organism to move very quickly in some cases. motility agar deeps are sued to test for motility. positive= fanning out away from the stab line. this can also make the tube look cloudy. negative= no fanning out from the stab line.
Why must solid and liquid samples be diluted prior to testing?
many samples are heavily contaminated with bacteria and must be diluted to provide an opportunity to visibly count colonies
what happens to gram positive cells if ethanol is left on for too long?
may decolorize causing misidentification of the bacteria
What happens if you plate the sample undiluted?
may have too many colonies to count
what happens when agar is added to growth medium?
medium becomes a solid
autoclaving
medium is heated to 121 degree Celsius at 15 psi for 15 minutes. this is sufficient to kill all microbes, including spores
Carbohydrate Fermentation Test - acid production negative test?
medium remains red
Carbohydrate Fermentation Test - acid production positive test?
medium turns yellow
if an organisms is e.coli what will you see on the EMB plate
metallic green
aseptic technique
method for transferring cultures from one medium to another without contamination
What is meant by binomial system of nomenclature?
method of scientific name-combination of genus and species, identify a species
What is the counter stain in an acid fast stain?
methylene blue (blue..obvi)
define ubiquitous
microorganisms seem to be present everywhere
How would you distinguish among the four classes of protozoans?
microscopic observation of the shape, size, number and type of nuclei, and type of motility
mesophilic
middle - loving; optimum growth at 30 degree Celsius - 37 degree Celsius. Pathogens of humans, grow best at body temperatures.
What kind of plate of used for the Casein hydrolysis test?
milk plate: nutrient broth with a skim milk additive
If positive test after 48 hours with Snyder test?
moderate susceptibility to dental caries
Why is moist heat more effective than dry heat as a sterilizing method?
moist heat penetrates material better than dry heat
What is the largest WBC?
monocytes
coliforms
most commonly used indicator. aerboic or facultatively anaerobic gram negative rods. do not form endospores and they ferment lactose which leads to acid and gas production
MPN
most probable number or MPN method. determines the number of coliforms in a sample
coarse and fine focus knobs
moves stage up towards objective lens or moves objective lens down to stage in order to focus image
Calculate the total magnification
multiply the magnification power of the lens, by the eyepiece lens 10x
Name Two genera that contain species that are acid-fast.
mycobacterium & Nocardia
Mycoplasma
neg for Gram Rxn-no cell wall
what general catagory of stains does capsule stain belong to?
negative stain
Color of pH indicator "Bromcresol green"
neutral -green acidic -yellow
MAC agar differential agents
neutral red lactose
What is the most abundant WBC?
neutrophils
type O blood has
no antigens, antibody A & B no agglutination
catalase: Negative result, Positive result, media used & reageant added
no bubble formation, bubble formation (oxygen-release), nutrient agar slant, hydrogen peroxide
Carbohydrate Fermentation Test - gas production negative test?
no bubble forms
Protozoa characteristics
no cell wall, organelles, asexual forms
Citrate Utilization - negative result?
no color change
Oxidase Test - negative test?
no color change
Decarboxylation Test - negative test?
no color change **may turn yellow if a glucose fermenter
Nitrate Reductase Test - negative test?
no color change - do confimation test by adding a small pinch of zinc powder
Urea Hydrolysis "Urea Broth" - negative test?
no color change -continue to incubate for 7 days for slow urease producers
y-hemolytic
no damage
What color do neutrophils stain?
no intense color
Hydrogen Sulfide Production "Triple Sugar Iron Agar" - negative test?
no precipitate
Station 1 Gelatin test Reagents added after incubation
no, but take tubes out and put into cold room for 20 minutes.
Do simple stains have a decolorization step?
no.
If urine samples were tested, should the presence of a few hundred bacteria indicate infection?
no; all normally collected urine samples have a few contaminants from the urethra
Will the use of serial dilutions indicate the presence of pathogens in a test sample?
no; serial dilutions only indicate the number of bacteria in a sample
Which cells do not retain the primary stain in an acid fast stain and what color do they end up?
non-acid-fast cells, blue
What kind of radiation is UV?
non-ionizing radiation
gamma
none
NA
nutrient agar
What is a common agar used in lab?
nutrient agar (NA), made of peptone, beef extract, sodium chloride, agar and distilled water.
What does paracentric mean?
objects place in exact center of the viewing field using one objective will still be centered after changing to another objective.
Is Clostridium an obligate or an aerobic anaerobe?
obligate anaerobe while most species of bacillus are aerobic
How is total magnification found? (mathematically)
ocular lens power (constant) x objective lens power
the x100 ocular lens is also called?
oil-immersion objective
Why do older bacteria not give reliable results when doing gram stain (+)?
older gram stain (+) cells bleach easier than younger cells and can stain pink which makes them appear gram (-)
Simple stain
one dye and dyes the cells
selective
only allow some organisms to grow; some inhibit growth of certain bacterial species
How many times is the fine adjustment know to be turned?
only slightly either direction
How do you know e.coli has been transformed if it grows on the medium treated with ampicillin
only transformed e.coli will contain the beta lactamase
how should the iris diaphragm be positioned for oil immersion objective?
opened
How do you calculate total magnification?
optic x ocular
index case
original source case
Decarboxylation Test - what must be done after inoculation?
overlay of mineral oil to seal the medium from external oxygen and promote fermentation
Selective ingredient for BEA test include:
oxgall (inhibits gram +) Sodium azide (inhibits gram -)
PLATE proteus is?
oxidase -, gram - rod
What reagent is used for the oxidase test?
oxidase reagent vial
What is the function of a Red Blood Cell?
oxygen and carbon dioxide transportation
What is necessary in an experiment to gain fluorescence?
pGLO gene, arabinose, ampicillin
What is the vector used in the transformation lab?
pGLO plasmid
MAC agar - purpose of neutral red
pH indicator low pH - red/purple/pink colonies neutral - colorless
MSA - purpose of phenol red
pH indicator low pH - yellow neutral pH - orangish red high pH - pinkish red
Bromothymol blue
pH indicator used in citrate test
disk-diffusion method
paper disks impregnated with various antibiotics are placed on a lawn of bacteria. antibiotic will diffuse into the media during incubation
What are peptones?
partial breakdown products of proteins
What does weak fermentation of sugar produce?
partial masking of the alkaline end products of peptone breakdown
alpha
partial, sometimes with a greenish appearance
Name the enzyme that help helps bacteria to develop resistance against penicilin?
penicilinase/beta-lactimase
What is the biochemical reaction for peptone breakdown?
peptone +O2 -------------------------->alkaline end-product
What does the carbohydrate fermentation media contain?
peptone- to support growth of the bacteria. carbohydrate- to test the bacteria. phenol red- pH indicator that changes to yellow to indicate acid production and a Durham tube- to collect gas that is formed.
What is the biochemical reaction for Peptones?
peptones + O2 --------------------> alkaline end product
What is the biochemical reaction for OF Glucose Peptones?
peptones + O2-------------> alkaline end products
What is a common way of preparing media?
petri plates, contain a solid media and provide a large surface area for isolating and observing colonies with the naked eye
What is the function of a Macrophage (lung)?
phagocytosis
What is the function of a Neutrophil?
phagocytosis
What is the pH indicator for Mannitol Salt Agar test?
phenol red
What is the pH indicator of TSI agar?
phenol red
What is the ph indicator for urease test?
phenol red
what is the pH indicator and percent salt solution used in mannitol agar
phenol red, 7.5% sodium chloride
what is fastidious?
picky about nutritional requirements
Tryptophan Hydrolysis "Indole Test" - positive test?
pink layer forms on surface of the medium
Mannitol Salt Agar
pinkish agar. positive - yellow surrounding colonies negative - no change in color around colonies presumptive test for s. aureus
What does "p" mean in transformation Experiment?
plasmid
high copy number
plasmid may have up to 300 copies of itself in any one bacterial cell.
pGLO
plasmid that contains an ampicillin resistance gene codes for exoenzyme ampicillinase.
Trichinella spiralis
plate Ham/Eggs
How many colonies are best for counting?
plates containing between 30 and 300 colonies
streptococcus pneumoniae
pneumonia
neutrophils...AKA?
polymorphonuclear neutrophils "PMNs" 2 to 5 lobes
What is a capsule?
polysaccharide-containing layer outside of a bacterial cell that can increase the bacteria's virulence, survival of desiccation and attachment to surfaces.
What is UV light limited by?
poor penetrating power
EMBA- eosin methylene blue agar
positive color result= green & pink indicator= eosin and methylene blue Positive organism= E.coli Carbon Source= Lactose
WALK AWAY PANEL urea is pink what does this mean?
positive for urea
be able to recognize positive and negative latex agglutination reactions
positive is the left blue circle showing clumps negative is the right blue circle, no clumbs
Starch Hydrolysis
positive organism= bacillus indicator= iodine clearing means= amylase present enzyme used= amylase negative organism = E.coli
MSA test
positive= growth of bacteria with a color change of media to yellow. negative= growth of bacteria without color change or no growth of bacteria
MAC test
positive= growth of bacteria with color change of media to bright pink. negative= growth of bacteria without color change or no growth of bacteria
capnophillic organisms
prefer higher concentrations of CO2 (5% - 10%)
endemic diseases
present in population all the time at low levels
Coagulase Test
presumptive for staph. aureus.
What are the 2 dyes used in a gram stain
primary dye (Crystal Violet) and a counter stain (Safranin)
With such a high count of bacteria in spoiled meat or milk, may we assume that the sample contains pathogens? Explain.
probably yes- the greater the contamination, the more likely the presence of pathogens
How do aerobic cells protect themselves from the effects of H2O2?
produce catalase
What is the function of a lymphocyte?
produces antibodies
OXIDASE Theory : A positive oxidase reaction reflects the ability of a microorganism to oxidize certain aromatic amines, such as tetramethyl-p-phenylene diamine (TPD),
producing colored end products. This is due to the activity of cytochrome oxidase in the presence of atmospheric oxygen.
Is Trypanosoma cruzi prokaryotic or eukaryotic?
prokaryotic
what are the proportions of osmotic pressure?
proportional to number of particles dissolved (solutes; often salt or sugar) in a certain volume of solvent (usually water)
Casease enzyme:
protease exoenzyme
Capsules
protective polysaccharide layer
Decarboxylation Test - positive test?
purple
What color do basophils stain?
purple
What color will gram positive bacteria be?
purple
On a blood smear which is the Lymphocytes?
purple color
Slide is of Cerebral Spinal Fluid and is a Gram + cocci. Describe what it looks like. What organism is it?`
purple round shape; strep pneumo
gram positive cocci
purple round shaped
define true motility
purposeful and directional swimming
What is produced when UV radiation is absorbs by DNA?
pyrimidine dimers - which interferes with DNA replication and transcription
What medium is used to test for coagulase
rabbit or human plasma positive is confirmatory for s. aureus
understand the basis for latex agglutination reactions
rapid confirmatory tests for s. aureus checking for protein A and coagulase
basophil
rarest less than 0.5% inflammatory events
Nitrate Reductase Test - positive test?
red color (nitrate reduced to nitrite)
Methyl Red Test "MR-VP Broth" - positive result?
red color develops
Nitrate Reductase Test - negative confirmation test?
red color- nitrate reduced by zinc, not the organism (confirms 1st negative)
Describe an Eosinophil cell
red granules
gram negative rod
red rod shaped
Slide is of Cerebral Spinal Fluid and is a Gram - cocci. Describe what it looks like. What organism is it?`
red round shape; Neisseria Meningitis
Station 14 TSIA Second tube
red slant/red butt - no fermentation. Peptone catabolized aerobically and anaerobically with alkaline products.
What color will gram negative bacteria be?
red/pink
When is phenol red red and when is it yellow?
red= pH above 7 yellow= pH below 7
osmotic pressure
refers to pressure required to prevent flow of water by osmosis.
dark repair
repair mechanism that does not require visible light.
microaerophiles
require low concentrations of oxygen (2% - 10%) for growth. higher oxygen concentrations will inhibit their growth and they cannot grow in the total absence of oxygen
WALK AWAY PANEL antibiotics are cloudy this means?
resistant - not a good drug to use
how are bacteria classified to an antibiotic based on the diameter of the zone of inhibition?
resistant, intermediate, susceptible
What are endospores?
resistive structures that resists adverse environmental conditions
What does aerobic respiration result in?
results in formation of hydrogen ions, converted to toxic hydrogen peroxides as part of the E.T.C.
light repair or photo reactivation
reverses structural changes with exposure to visible light.
What shape is Bacillus/bacilli?
rod shaped
What shape does the lymphocyte nucleus have?
round and takes up most of the cell
the x4 ocular lens is also called?
scanning objective
streptococcus pyogenes
scarlet fever
Mature neutrophils...AKA?
segs
Is PEA selective or differential?
selective
What is the purpose of PEA testing?
selects for Gram + organisms, and is used to isolate them from cultures where they are mixed with Gram - bacteria
Bile Esculin test (BEA)
selects for bacteria that can tolerate bile salts. differentiates species that rely on hydrolysis of exculin to form a dark brown or black color change. positive= growth of bacteria with a color change of the media to black. negative= growth of bacteria without color change or no growth of bacteria.
Eosin Methylene Blue Agar (EMB)
selects for gram-negative rods. differentiates between lactose fermenting and non-lactose fermenting. lactose fermenters form colonies with dark centers and clear borders while the non lactose fermenters form completely colorless colonies. positive= growth of bacteria with color change of colonies that have dark centers (magenta or purple), E coli will have a metallic green sheen. negative= growth of bacteria without color change or not growth of bacteria.
What is the purpose of mannitol salt agar?
selects for organisms that can grow in a 7.5% NaCL enviromment.
What is the difference between semisolid agar deeps, petri plates, and slants?
semisolid agar deeps contain .5% -. 7% agar instead of the 1.5% in Petri plates and slants
A relatively large zone inhibition surrounding a anitmircrobil disk would be interpreted as a what a reaction
sensitive
WALK AWAY PANEL antibiotics are clear this means?
sensitive - good choice
why is important to distinguish streptococcus pneumonia
serious pneumonia the other won't cause ...
SBA
sheep blood agar
citrate utilization
simmons citrate agar tests ability to utilize citrate as a sole carbon source and for presence of alkaline products as a result of citrate utilization. indicator bromothymol blue will detect a pH change of greater than 7.5. positive= green to blue. negative= no color change
this is e aerogenes, this is a positive result for simmons citrate, it is blue
simmons citrate test
this is e coli, it has a negative citrate result. it is green
simmons citrate test
What is a pure culture?
single species or kinds
What is the difference between slant tubes and plates?
slants provide a solid growth surface in a tube form, which takes less room and is easier to transport than plates
Entamoeba histolytica
sleeping sickness
what causes trypanosome
sleeping sickness
If positive test after 72 hours with Snyder test?
slight susceptibility to dental caries
describe a plasmid and some of its characteristics
small circular DNA structure separator from chromosomal DNA bacteria
plasmids
small extra-chromosomal elements that can exist in some bacteria. carry genes for antibiotic resistance, and carry genes for other proteins that may be beneficial
What do the small pores in the gram positive peptidoglycan layer do?
small pores enable them to retain primary dye (crystal violet a purple dye) when samples are washed with alcohol
Why are petri plate cultures inverted when they are in the incubator?
so that condensation doesn't drip on cultures
Station 1 Gelatin test Negative result:
solid
What is the purpose for agar in lab?
solidifying agent
Amylose:
soluble starch
hypertonic
solute concentration is greater outside of the cell. water flows out
hypotonic
solute concentration is lower outside of the cell. water flows in
Results of LB/AMP plate with +pGLO?
some growth of bacteria as it will have amp resistance
MSA - differential
some species also ferment mannitol into acid. this acid production turns pH indicator from red to yellow (mannitol break down)
What organism and legume did we use for nitrogen fixation
soybeans, B. japonicum (Bradyrhizobiuim japonicum)
E. coli JM 83
specially designed for transforming. contains no plasmids, and makes no restriction enzymes.
Describe a simple stain
stains all the bacteria the same way, so you can more clearily see each cell or its specific cell components
Negative stain
stains the background
CATALACE what organism is double zone hemolosis (catalace positive)?
staph aureus
What is the CAMP factor?
streptococcus agalactiae produces hemolysin with staph. aureus.
virulence factors
structures or substances produced by a microorganism which enhance its ability to cause disease
Spores
structures that can survive for long periods of time referred to as "resting bodies" due to their metabolically inert state.
epidemiology
study of patterns of disease infection and spread
How are enzymes named?
substrate name + suffix of -ase Fructose=Fructase Starch=Amylase Glucose=Glucase
What is the critical step in performing the acid fast stain?
successfully forcing the primary stain inside the cells by using heat
In lab 5 (identifying an unknown), which mediums needed to be innolculated with a loop?
sugar fermentation tubes, urea broth tube and nutrient agar slant.
What is the biochemical reaction for TSI?
sugar------------------------> acid with/without gas
What is the purpose of the SIMs test?
sulfur reduction, indole pretection, and motility
How is ferrous sulfide formed?
sulfur-containing amino acids are broken down into hydrogen sulfide which is then combined with iron sulfate in the tube and forms ferrous sulfide.
What is growth medium?
supports growth of bacteria
WALK AWAY PANEL the bottom part is for the?
susceptability
What is reported out to Physicians from the Kirby-Bauer?
susceptibility or resistance
What technique is used for the Kirby-Bauer test?
swab and make a bacterial lawn
What technique was used for UV test?
swab and make a bacterial lawn
what kind of relationship do the organism and the legume have
symbiotic
gresiofulvin, anti-fungal agent
synthesized by some fungi, exact mechanism is unknown, thought to interfere with spindle fiber components (tubulin) and blocks mitotic events. used in treatment of the nail and skin fungal infections (Hint: difficult name - don't know how it works)
What does an increase in neutrophils indicate?
systemic bacterial infection
flucytosine, anti-fungal agent
taken by yeast cells and converted into active inhibitory form, inhibits nucleic acid synthesis (Hint: fluc~fuc~totally screwed~you are totally screwed if you can't make nucleic acid)
What are the primary differences between tapeworms and flukes?
tapeworms possess a head end called a scolex and are segmented into units called proglottids
standard plate count
technique often used to determine the number of bacteria in a sample
Indirect ELISA - what are we testing for?
test for antibodies "Host response"
Phenol Red Broth - purpose?
test for fermentation of carbohydrates and gas production
MSA - purpose of mannitol?
test for fermentation of sugars
Snyder Test - purpose
test for growth of oral bacteria
Catalase Test - purpose?
test for presence of catalase
starch hydrolysis
tests for amylase combined with water breaks down large polysaccharides into smaller molecules that can be used for energy. positive= a clear halo around the colonies after the addition of gram's iodine, negative= the entire medium is dark blue/brown
nitrate reduction test
tests for the ability to reduce nitrate to nitrite. if the organism can reduce the nitrate it will react with the reagent (paba) positive= yellow, pink or red color change after the addition of papa. negative= no color change
urea hydrolysis
tests for urease enzyme that breaks down urea to form two molecules of ammonia. ammonia products form a basic environment that causes the media to change from a light orange to magenta. positive= bright pink slant. negative= light orange to yellow
define resolving power
the ability of a lens system to distinguish two neighboring points as seperate and distinct
What is the purpose of the DNAse test?
the ability of a organism to utilize nucleotides from DNA or RNA as a nutrient source
What does Methyl Red test determine?
the ability of an organism to produce acid end product from glucose fermentation
What does Voges-Proskauer test determine?
the ability of some organisms to produce a neutral end product during glucose fermentation
What does resolution mean?
the ability to distinguish between two adjacent objects
Why should the rheostat never be turned higher than 7?
the bulb burns out too quickly
The size of the zone of inhibition does not indicate ___________
the degree of effectiveness of a chemical agent
CO₂ uptake is related to the __________
the increased growth of anaerobic organisms
Oxygen uptake is directly proportional to __________
the increasing number of vigorously growing aerobic cells
What is the Kovac's reagent used for?
the indole production in SIMs
MONOCYTE
the largest in sizeof WBC 3-7% 3rd place turn into macrophages kidney shaped
What is thermal death time (TDT)?
the length of time required to kill all bacteria at a given temperature
why is it wrong to turn the fine adjustment more than slightly in either direction?
the object could become out of range and it could damage the lenses
What does OF GLUCOSE test determine?
the organism's ability either to oxidize glucose or to ferment glucose
What does Catalase Test determine?
the presence of the enzyme, catalase
what does the oxidase test detect?
the presence or absence of cytochrome C
How is sugar fermentation detected?
the production of acids
what is hemolysis
the rupture or description of red blood cells
What is the critical step in doing a gram stain?
the timing of the decolorizer
presumptive test (acid and gas production)
the tubes that test positive in this test go on to be confirmed using MUG (methylumbelliferyl-beta-D glucoronide) agar or EMB agar
Why do ordinary stains like gram stain not work on acid fast bacteria?
these cells have a waxy lipid cell wall
How would immunosuppressive drugs predispose a patient to opportunistic fungi?
these drugs greatly reduce the natural immune state especially the cellular immunity which is essential in controlling these infections
Why are arthropods important to microbiology?
they represent important agents (vectors) of disease transmission
Describe the gram negative peptidoglycan layer.
thin layer with larger pores, therefore they cannot retain the primary dye and become colorless after being washed with alcohol
kirby bauer test
this depends on the sensitivity of a bacteria to an antimicrobial= zone of inhibition name of inoculation technique? bacterial lawn
Results of LB/AMP with no pGlO?
this is our negative control as there is no growth because there is no plasmid to give it resistance to the AMP
Results of LB with no pGLO?
this is our positive control as there is growth because there is no amp present to stop growth
the one on the left is positive, the one in the center is negative, and the one on the right is an un-inoculated tube
this is simmons citrate test
methyl red test, e coli (mr positive) on the left and e aerogens (mr negative) on the right. page 82
this is the methyl red test.
e. aerogenes is vp positive, this is the red/wine color indicative of a vp positive test.
this is the vp test
e. coli (vp-negative) is on the left and e. aerogenes (vp-positive) is on the right. atlas page 98
this is the vp test
e. coli is vp negative,
this is the vp test
biological transmission
through bite of an infected mosquito, tick, or flea
Why do we place the tubes on ice after the heat shock?
to close the pores of the E. coli so the DNA will stay inside
What is the purpose of the Starch test?
to detect the presence of amylase
What is the purpose of the Simmon's Citrate Agar?
to detect the presence of an exoenzyme known as citrate permease
What is the purpose of the Casein Hydrolysis test?
to detect the presence of the casease enzymes
What is the purpose for Oxidase testing?
to detect the presence of the endoenzyme, cytochrome oxidase
What is the purpose of the nitrate reduction?
to determine if enzyme nitrate reductase was produced to reduce nitrate to nitrite
What is the purpose of the Oxidase test?
to determine if the bacterium of interest has cytochrome C oxidase in its electron transport chain
What is the purpose of the Urease test?
to determine rapid or slow urease
Gelatin Liquéfaction test "Nutrient Gelatin" - Purpose?
to determine the ability of an organisms to produce the enzyme gelatinase
What is the purpose of 6.5% NaCL Broth test?
to differentiate between strep that can grow in 6.5 % salt environment and those that cannot
What is the purpose of the catalase test?
to distinguish between the gram-positive cocci
Why must 9 ml sterile water blanks be used for each dilution rather than 10 ml blanks?
to each sterile water blank, we add 1 ml of specimen, thus the volume is then 10 mls for a 1:10 dilution
Why are bacteria inoculated into various growth media as pure cultures?
to identify bacteria, without introducing unwanted microbes (contaminants)
Decarboxylation Test - purpose?
to identify organims that have decarboxylases to break down amino acids
Why is there an indent in the tube for testing for citrate?
to inhibit 02 from reaching the bottom of the tube
What does subculture mean?
to inoculate a new sterile place from the old culture
Why are selective and differential media used?
to isolate certain bacteria and differentiate one from another by the biochemical reactions they perform
When opening a culture tube, what is the purpose of flaming the mouth of the tube?
to kill any contaminants and to release a puff of air
What are the reasons for heat-fixing the smear?
to kill the bacteria and it also helps the bacteria adhere to the slide
Why are we using GFP?
to show visual evidence that the DNA transformed with successful gene expression
Whats the purpose of flaming the inoculating loop?
to sterilize for aseptic technique
calculate total coliform count
total coliforms/100mL = coliform colonies counted divided by he number of mLs sampled. Multiply the product by 100. Answer in CFU/mL
Define sterile
totally free of organisms
What will negate the charge of DNA in the transformation lab?
transforming solution
citrase
transport citrate into the cell and make it available for energy catabolizing processes.
Describe two methods used to make e.coli competent to up take the plasmid
treated with calcium chloride and used to
would person living in the desert or tropics have a larger number of bacteria living on their skin
tropics
blood agar contain red blood cells
true
TSA
tryptic soy agar plate
Hydrogen sulfide production: Negative result, Positive result, media used & reageant added
tube is less than 50% black, tube is more than 50% black (ferrous sulfide forms), semi-solid media, iron sulfate
Mycobacterium tuberculosis
tuberculosis
Oxidase Test - positive test?
turn bacteria violet to purple immediately
what role does arabinose play in transformation
turns on the green/ inducerin recombanted DNA
what is a mixed culture?
two or more kinds
Compound Microscope
two or more lens to view an object
Selective & Differential
type of media Mannitol/Salt agar is
Replica plating
type of plating used to isolate bacterial mutants
What does the medium contain for the Urease test?
urea phosphate buffer and phenol red
fine adjustment knob
used for 40x and 100x (oil immersion) lenses
indicator organism
used to determine if there is fecal contamination. this indicator is present in human waste in high enough numbers to be readily detected and easy to find.
MR test
used to identify bacteria that produce stable acid end products by means of mixed acid fermentation of glucose. a pH indicator methyl red is added and in acidic environments will turn red. neutral environments it will be yellow. positive= red, negative= no color change
Fine adjustment knob?
used to sharpen the focus, don't turn too many times objectives may crash into the slide
Citrate Utilization - what is going on?
uses citrate breaks down the ammonium salts to ammonia, which creates an alkaline pH
Differential stain
uses more than one dye and stains different kinds of organisms different colors
Citrate Utilization (SC) - purpose?
using citrate as the sole source of carbon with production of enzyme citratase
if a microbe can produce cats
water oxygen
normal flora
we harbor normal flora in and on us some of these microbes are potentially pathogenic (disease causing)
understand the regulation of the pGLO plasmid
we make the cells competent through addition of CaCl2 and heat shock, making them able to take up naked DNA (plasmid). those that take up the plasmid will be able to grow on a TSA plate with ampicillin present.
TSI- Triple Sugar Iron
what are the three sugars used?- glucose, lactose, and sucrose yellow means acid fermentation yellow with bubbles or tears in agar= acid fermentation and gas end products black=sulfur reduction red= alkaline yellow color change= E.coli Red color= Alcagenes
Negative
what kind of staining is this?
Phenol red broth
whats the name of the tube used? Durham tube what organism caused the yellow tube and gas? E.coli what organism caused no color change? Alcagenes indicator: phenol red
When does endospore reproduction occur?
when bacteria do binary fission
How are spores produced?
when environmental conditions are poor, meaning essential nutrients and water are not available to the cell.
What are oxidizers?
when glucose is utilized only in the presence of O2
When are bacteria considered to pigmented?
when it has more density it will appear to be black or dark brown
define parfocal
when one lens is in focus, the other lenses will be in focus with only minor adjustments to bring the object into sharp focus
the one with the pink is positive for the indole test. it has tryptophanase which will break down the tryptophan amino acid into indole/ammonia/pyruvate. the Kovac's reagent (DMB(reacts with free indole to form complex under acidic conditions)/amyl alcohol(allows complex to float on medium)/HCl(provides acidic conditions) is used to detect this
which one is positive for the indole test and why?
Voges-Proskauer "MR-VP Broth" - positive result?
wine red color develops
aseptically
without introducing other microbes
What are the 4 ocular lens settings?
x4, x10, x40 and x100
If the optic lens is x10 and the ocular lens is set at x40 what is the total magnification?
x400
Phenol Red Broth - positive test?
yellow
Methyl Red Test "MR-VP Broth" - negative test?
yellow color develops
Phenylalanine Deamination "Phenylaline Agar"- negative test?
yellow color develops
Mannitol Salt Broth positive and negative
yellow is positive - presumptive S. aureus red is negative - presumptive non-pathogenic Staphylococcus
Tryptophan Hydrolysis "Indole Test" - negative test?
yellow layer forms on surface of medium
Station 14 TSIA Third tube
yellow slant/yellow butt and agar lifted - glucose and Lactose and/or Sucrose fermentation and acid accumulation in slant and butt, also produced gas.
What observations are made in lab with Kirby-Bauer?
zone of inhibition
Basophils
~Appear in many specific kind of inflammatory reactions, particularly those that cause allergic symptoms
Platelets
~Blood clots ~Store and transfer chemicals
Monocytes
~Can easily be transported to the site of infection (Host defense)
Red Blood cells
~Carry Oxygen from lungs to tissues and other organs ~Getting waste carbon dioxide from your tissues to your lungs
Neutrophils
~Inflammatory events ~Phagocytosis (ingest and kill micro-organisms)
Eosinopils
~Movement to inflamed areas ~Trapping substances ~Killing cells ~Antiparasitic and bactericidal activity ~Participating in immediate allergic reactions ~modulating inflammatory responses
Lymphocytes (T cells and B cells)
~T cells can only kill unhealthy cells and cannot kill pathogens that live outside the cells ~B cells produce antibodies
On a blood agar plate, what does a green zone around colonies indicate?
α-hemolysis
On a blood agar plate, what does a clear zone around colonies indicate?
β-hemolysis
On a blood agar plate, what does no zone around colonies indicate?
γ-hemolysis
Pseudomonas aeruginosa
• motile (one or more polar flagella) • rod shaped and aerobe • Gram-NEGATIVE bacteria. They are found almost everywhere, in soil, water, plants and animals. • Opportunistic POSITIVE CATALASE RESULTS = Liberation of Bubbles
salmonella enterica: General Characteristics
•Enteric pathogen •motile •lactose non-fermenter •H2S producer •Ferment glucose by one of two major pathways to a variety of end products
Mannitol Salt Agar (MSA)
•selective/differential •selects (salt) inhibits most G+/G- bacteria from growing •differentail (mannitol) mannitol can fermented by S. aureus, so this media differentiates S. aureus from other staph (becuase it is the only on that can ferment mannitol) •mannitol fermentation results in acid production, pink → yellow •when you streak for isolation in this media, a section of it will remain pink, why? becuase the isolated colonies don't have enough bacteria to produce enough acid to perform a color change like on the rest of the plate, or colonies simply did not grow there at all
Methyl Red Test "MR-VP Broth" - products from the breakdown of formic acid?
CO2 and H2
What is a faculative anaerobe?
Can grow with or without oxygen, but grow better in oxygen so they will grow through out the tube but mainly on top.
Starch Hydrolysis
Can this bacterium make the enzyme amylase?
Yeast that causes thrush
Candidia albacase
MSA- Mannitol Salt Agar
Carbon source= Mannitol indicator: phenol red positive organism= S. aureus yellow halo means= mannitol fermenter
Station 13 Casease test Enzyme
Casease
Station 13 Casease test Know the protein in milk (substrate)
Casein
CATALASE TEST
Catalase is an enzyme that converts hydrogen peroxide into water and oxygen. The presence of catalase can be detected by the slide method. A drop of 3 percent hydrogen peroxide is put on a slide and the bacteria is emulsified in the drop. The presence of bubbles is evidence of the production of OXYGEN. Alternatively, bacteria may be tested by dropping hydrogen peroxide directly onto colonies growing on a plate.
Why do we add zinc dust to a nitrate test if no color change occurs after the reagents?
Catalyzes the reduction of any nitrate to nitrite, producing a red color
Mixed acids
Causes Methyl Red to turn red
Station 10 Parasitic worms Class
Cestodes, Tapeworms, leaches ect.
Mutation
Changes in the genetic material
Hemolysin
Chemical that can break down red blood cells
Fungi characteristics
Chitin in cell walls, unicellular or multicellular, lack chlorophyll, heterotrophs
What's the purpose for CAMP test?
Christie, Atkins, Munch-Peterson is used to differentiate Streptococcus agalactiae.
Organisms lacking _____ will not survive on the Simmons citrate medium.
Citrate-permease
-Aspergillus -Candida -Coccidioides -Histoplasma ^^^^all are ASCOMYCETES and appear to form ascospores as a sexual means of reproduction -Deuteromycetes = all other fungi that sexual means of reproduction is unknown
Classification of Mycoses
Match the disease causing organism listed on the left with the description or disease on the right. Answers may be used more than once. Claviceps purpurea a. Malaria Toxoplasma gondii b. Sheep liver disease Plasmodium falciparum c. Ergot poisoning Fasciola hepatica d. Hookworm Necator americanus e. Cat feces disease
Claviceps purpurea = C Toxoplasma gondii = E Plasmodium falciparum = A Fasciola hepatica = B Necator americanus = D
Station 13 Casease test Positive result:
Clearing around the growth, means the bacteria produced casease, so the protein in milk casein will be digested
Station 12 Starch test Positive result:
Clearing around the organism, means amylase was produce and starch was broken down.
Bound coagulase is also called:
Clumping factor
***If plasma becomes clumpy and or solidifies, then bacteria are coagulase positive **Test is only valid on gram + staphylococcus like bacteria since gram negative bacteria are able to provide false positive reactions from a non coagulase like mechanism. ****Staphylococcus aureus has clotting virlence factor, causeing the solidification on the media.
Coagulase test
The Novobiocin test is used to differentiate:
Coagulase-negative staphylococci
Bacillus subtilis -Colonies of B. subtilis grown on a culture dish in a molecular biology laboratory.
Colonies of B. subtilis grown on a culture dish in a molecular biology laboratory.
Red
Color Voges-Proskaeur test turns when positive
Blue
Color seen in citrate test when pH is higher than 7.6
Green
Color seen in citrate test when pH up to 7.5
Pink
Color urease agar turns when urease is present
Red= negative sugar fermentation, negative H2S, Yellow= positive sugar fermentation Black= presence of hydrogen sulfide
Colors and what they signify in the result of a triple sugar iron agar test
Red = negative, Yellow = positive
Colors that signify positive or negative in a Phenol Red carbohydrate fermentation test
Compare the geographic distribution of: -Candidiasis= entire United States -Filobasidielliosis (Cryptococcosis)= entire United States -Histoplasmosis= Mississippi River Valley regions -Coccidioidomycosis= Western States; Sonoran Valley; West TX
Compare the geographic distribution of: -Candidiasis -Filobasidielliosis (Cryptococcosis) -Histoplasmosis -Coccidioidomycosis
Peptone, glucose, Phosphate buffer
Contents of MRVP broth
Hydrogen Sulfide Production "Triple Sugar Iron Agar" Enzyme
Cysteine Desulfurase
Enzyme that is an electron carrier in the electron transport chain. Present in bacteria that utilize oxygen.
Cytochrome oxidase
1 ml of a 1:5 X 10^5 dilution of milk was plated in duplicate. Plate A contained 230 colonies, plate B contained 270 colonies following incubation. How many bacteria were present in a milliliter of the original sample?
DF = 500,000 TVB/ml = PC X DF PC = 230 = 250 X 500,000 270 = 125,000,000 500/2 = 250 Ave PC TVB/ml = 1.25 X 10^8
What medium is used for DNAse?
DNAse plate: nutrient agar with DNAse added
**Tests for exoenzyme DNase which is able to hydrolyze DNA ***Zones of clear around streaks either before or after addition of 0.1N HCl is a positive result for the presence of DNase
DNase test
What is the most important step in a differential stain?
Decolorization (alcohol) because at this point you can distinguish between 2 bacteria. For example: Gram + have a violet color after this step and Gram - are colorless.
***Selects for gram -, lactose - microorganisms **Some Lactose + colonies do grow but they will appear Red
Desoxycholate Citrate test
Indole Production Test
Determines the ability of microorganisms to hydrolyze tryptophan Kovac's Reagent -- red reagent layer = Positive
The purpose of a standard qualitative analysis of water
Determines the presence of coliform which indicates fecal contamination
Is Phenol Red Broth selective, differential, or enriched?
Differential for Enterobacteriaceae
Is Simmons citrate selective, differential, or enriched?
Differential for facultative anaerobes
Importance of using blood agar
Differentiates ability to lysis the red blood cells and provides nutrient
Corynebacterium Diphtheriae
Diphtheria
No
Does micrococcus luteus cause hemolysis?
Yes
Does staphylococcus aureus cause hemolysis?
oxidase: Negative result (before 20 sec), Positive result (before 20 sec), media used
Dryslide remains colorless, dryslide turns blue/purple (cytochrome C is present), nutrient agar slant + oxidase dryslide
Which gram negative organism would result in a metallic green sheen after culturing in a EMB agar
E. coli
Least resistant bacterium:
E. coli and S. aureus
Why is E. coli more susceptible to boiling than B. pumilus?
E. coli lacks the endospores that B. pumilus possesses
What organism produces pink colonies when grown on Maconkey agar? found in a water test?
E. coli; fecal decontamination
What media is used to grow Gram negative enteric bacteria?
EMB, Hektoen Does not grow gram + due to bile salts and some dyes.
Which selective medium would be best to determine the amount of acid produced by gram negative bacteria
ESA methylan blue agar
Hemophilus Influenza
Ear infections, bronchitis, pneumonia, meningitis
This tapeworm can form large hydatid cysts virtually anywhere including the lungs and brain.
Echinococcus granulosis
These organisms are typically oxidase negative:
Enterobacteriaceae
These eggs can hatch into large intestinal worms that will feed on the victim's blood like Dracula.
Enterobius vermicularis
ELISA
Enzyme Linked ImmunoSorbant Assay
Cytochrome Oxidase
Enzyme present if the paper in a Cytochrome oxidase test turns purple/blue
Gram +
Eosin Methylene Blue (EMB) agar inhibits growth of this type of bacteria
EMB
Eosin Methylene Blue Agar
Selective and differential Contains eosin and methylene blue dyes to inhibit gram (+) bacteria Contain lactose and sucrose to distinguish bacteria that ferment and don't ferment
Eosin Methylene Blue Agar
What is name for a condition with a lot of Eosinophils in the blood?
Eosinophilia
What kind of white blood cells are triggered by allergic reactions and parasitic infections?
Eosinophils (phagocytic)
Widespread occurence of an infectious disease in a community at a particular time
Epidemic
2H2O2 > 2H2O + O2 (Hydrogen Peroxide > Water and Oxygen)
Equation for the reaction of catalase
Which bacteria has mechanisms to repair damage from UV radiation?
Escherichia coli
What happens to produce a positive result in a Bile Esculin Test?
Esculin molecules split, esculetin reacts with Fe3+ from ferric citrate and forms a dark brown precipitate
Pseudomonas aeruginosa
Example bacteria that is Cytochrome oxidase positive
Hemolysin
Exotoxin that lyses RBC
True/False: All of the protists exhibit an ability to form antibiotic resistant structures called cysts.
False
True/False: All protozoans have complex methods of reproduction such as seen with malaria.
False
True/False: Animal parasites such as roundworms reproduce most commonly by producing asexual spores.
False
True/False: Antibiotic sensitivity plates are covered with bacteria using the loop and following the dilution streak plate technique.
False
True/False: Ascaris lumbricoides is the smallest roundworm and measures only 1mm in length.
False
True/False: Biological vectors would include ants and houseflies.
False
True/False: Body lice only transmit diseases mechanically and are therefore harmless vectors.
False
True/False: EMB is the most common culture media used in the Kirby Bauer sensitivity test.
False
True/False: Fortunately animal parasite worm infections are not very common in the world today.
False
True/False: Fungal infections are commonly spread through the air by means of their cysts.
False
True/False: If an organism is sensitive to one antibiotic it will automatically be sensitive to others.
False
True/False: Infections caused by fungi are commonly known as helminth infections.
False
True/False: Malaria is caused by species of Leishmania.
False
True/False: Ringworm can be treated with anti-worm medication such as mebendazole.
False
True/False: Ticks absorb blood directly from the victim's intestinal tract.
False
True/False: To ensure elimination of tapeworm infections, the proglottids must be removed from the host.
False
True/False: Trichinosis is a common pinworm infection affecting children most of the time.
False
True/False: Zone diameters of sensitivity are measured in inches to be as accurate as possible.
False
This worm is acquired from contaminated deep fried chicken livers.
Fasciola hepatica
What does EMB isolate?
Fecal coliforms
Coliforms
Fecal contamination is identified by finding ______ in the water.
Trypanosoma gambiense
Flying Birds
a. they produce resistant cysts. b. they are antibiotic resistant c. *they produce infectious spores* d. they take steroids and are tougher than we are
Fungi are dangerous to work with in the lab because: a. they produce resistant cysts. b. they are antibiotic resistant c. they produce infectious spores d. they take steroids and are tougher than we are
Proteus vulgaris
GNR
Pseudomonas aeruginosa
GNR
Salmonella
GNR
Serratia marcescens
GNR
Shigella
GNR
Corynebacterium
GP pleomorphic rod
Enterococcus
GPC
Streptococcus
GPC
Staphylococcus aureus
GPC "in clusters"
Strep pyogenes
GPC in chains
Strep agalactiae
GPC in long chains
Streptococcus pneumonia
GPC in pairs
Staph epidermidis
GPC in pairs and tetrads
Staph saprophyticus
GPC in single or pairs
Bacillus megaterium
GPR
Clostridium
GPR
In a TSIA slant, cracks or lifted medium indicate:
Gas production
Cracks, Lifting
Gas production can be determined by ------- and/or the -------- of the media off the bottom of the tube.
This is the only protozoan that has functional eyes which it uses to attack and bite its next victim.
Giardia intestinalis and G. lamblia
What provides the carbohydrate in MR/VP broth?
Glucose
In a TSIA slant, a yellow slant/yellow butt indicates:
Glucose fermenter, and fermenter of one of the other sugars
In a TSIA slant, a red slant/yellow butt indicates:
Glucose fermenter, no lactose or sucrose fermentation
Obtain an entire yard of bacteria
Goal of a spread plate
Obtain individual colonies of bacteria
Goal of a streak plate
Neisseria Gonorrhoea
Gonorrhea
Properties of a COLIFORM
Gram (-) Non spore forming Bacillus - rod Lactose + and produces gas/acid
Negative
Gram ___________ intestinal pathogens are a major concern for public health since the two main pathogens Salmonella and Shigella have the ability to cause enteric fevers, food poisoning, dysentery, and even typhoid fever
What color is each kind of bacteria after ethanol is added (and washed off)
Gram+ = purple Gram- = colorless
Is Catalase used for Gram-positive or Gram-negative organisms?
Gram-positive
What are the two types of white blood cells?
Granulocytes & Agranulocytes
Do bacteria have a greater or smaller variety of metabolic processes than eukaryotic organisms?
Greater
Station 2 Phenol Red media Cap colors:
Green - Lactose Light pink - sucrose Red - glucose
Station 9 Citrate test Postive result:
Growth on slant, turns blue
What is the biochemical reaction for Ferric Ions?
H2S + ferric ions-----------> ferrous sulfide
Who formulated the Gram Stain?
Hans Christian Gram (1884)
Scolex
Head of a worm
What is the mordant in acid-fast stains and endospores?
Heat because heat drives the stain into the cell/cell wall.
What is the main difference between an acid fast stain and a Gram stain?
Heat must be applied to an acid fast stain to hold in the stain
Clear around colonies
How amylase positive bacteria appear on Amylase positive test result
-Oral candidiasis = Nystatin or Amphotericin B -Taenia pedis = Griseofulvin -Filobasidielliosis (Cryptococcosis) = Amphotericin B -Ringworm = Griseofulvin, Mycosyl -Aspergillosis = Amphotericin B -Pneumocystis pneumonia = Trimethoprim/Sulfamethoxazole and/or Pentamidine
How are the following mycoses treated? -Oral candidiasis -Taneia pedis -Filobasidielliosis (Cryptococcosis) -Ringworm -Aspergillosis -Pneumocystis pneumonia
Binary fission
How bacteria reproduce
Abstinence or condom use Not sharing needles Using gloves and masks (medical staff)
How can HIV be avoided?
-these pathogenic yeasts have been known to colonize birds -the yeasts can survive for long periods of time in bird droppings
How could pigeons or starlings contribute to the spread of Filobasidiella neoformans?
Involves enzymes detected by endonucleases. DNA polymerase I fixes it & ligase closes the gap.
How does Dark-repair (excision repair) fix DNA?
Small amount
How much blue color is necessary to indicate that a citrate test is positive?
Clonorchis sinensis
Human Liver Fluke
pH indicators and respective medium and color produce?
Hydrogen Sulfide Production "Triple Sugar Iron Agar" Phenol Red
WALK AWAY PANEL the top part is for the?
ID
Glucose + Lactose + H2S - Escherichia Enterobacter
Identify this KIA tube
Glucose + Lactose - H2S + Salmonella Proteus
Identify this KIA tube
Glucose + Lactose - H2S - Shigella ****NO gas in KIA butt
Identify this KIA tube
Glucose - Lactose - H2S - Pseudomonas Alkalingenes
Identify this KIA tube
Facultative
Identify this OF Glucose tube
No respiration
Identify this OF Glucose tube
Strictly Oxidative
Identify this OF Glucose tube
Strictly fermentive
Identify this OF Glucose tube
What are TSI slants used for?
Identifying Gram (-) bacilli
Cysteine desulfurase
If a bacteria contains the enzyme ------------, a black precipitant will form
Station 12 Starch test Principle
If bacteria produces amylase, it breaks down the substrate starch.
When do we test for antibodies?
If someone was exposed a long time ago
When do we test for antigens?
If someone were to get stuck with an infected needle
What is the purpose of Methyl Red and Voges-Prokauer (MRVP) ?
If the end products of carbohydrate metabolism is acidic or neutral. MR - Mixed Acid Fermentation VP - Acetone
How soon can the MR test be read after adding reagent?
Immediately
when did the practice of washing hands become significant?
In 1846 the method became significant as a method of infection prevention
Negative, Green, Blue
In OF Glucose test, no color change results in a _______ result. Brom Thymol Blue is actually _______, but turns _______ in highly negative results (high basic pH)
Brom Thymol Blue
In OF Glucose test; media contains pH indicator ---------, which turns yellow if the glucose is utilized, and acids are produced.
Mineral oil
In OF Glucose test; two tubes are inoculated, with one of the tubes covered in -------- to prevent air from reaching the media.
Bubble
In the catalse test, bacteria that are + cause hydrogen peroxide to do this
Phenol Red
Indicator that is sensitive to pH and turns yellow in the presence of acid.
Litmus milk test
Indicator: Litmus pink= lactose fermentation what organism caused pink color? e.coli white= litmus reduction what organism caused white color? enterococcus blue= hydrolyze casein basic
In a SIM test, no red color after Kovac's reagent indicates:
Indole negative
In a SIM test, a red color after Kovac's reagent indicates:
Indole positive
Beta-Lactams
Inhibit cell wall synthesis Ex: Penicillin G
Sulfamides
Inhibit synthesis of nucleic acids Ex: Sulfamethoxazole
Tetracyclines
Interfere with translation by bonding to ribosomes
What reagent is used for Starch test?
Iodine
Positive
Is patient A positive or negative for Clostridium difficile?
Negative for Streptococcus
Is this test positive or negative? For what?
What is a major limitation to UV radiation?
It cannot pass through solid surfaces
How does the oxygen dryslide change colors?
It contains a chromogenic substrate that oxidase-positive bacteria will change blue
Why can't a disinfectant be ingested?
It contains harmful chemicals that will breakdown our natural protective barriers.
Where does the acid come from in the sugar fermentation test?
It is an end product of the break down of sugar
What is needed to obtain bioluminescense?
It is positive for pGLO and the arabinose activates the GFP causing it to glow.
Station 7 Kirby Bauer test Know the name
Kirby Bauer Test
GIve another name for antibiotic Susceptibility Test?
Kirby-Bauer
What method is used for the antimicrobial susceptibility test?
Kirby-Bauer
Antimicrobial Susceptibility Test..AKA
Kirby-Bauer or disk diffusion test
What organism would be on the capsular stain?
Klebsiella
Tests for ability to ferment glucose and/or lactose, tests H2S production, pretty much the same thing as RDS test but the difference is that KIA contains iron salts to determine H2S production.
Kligler's Iron Agar (KIA) test
What reagent is used to indicate the presence of indole?
Kovac's Reagent
What reagent is used for the SIM?
Kovac's reagent
Station 3 Indole test Reagent
Kovacs
What type of agar is used for Bacterial Transformation lab?
LB - Luria Bertani
MAC agar - purpose of lactose
LF - lactose fermentation NLF - no lactose fermentation
Bacteria are most sensitive to chemicals in which stage of development?
LOG stage (they are not actively growing)
What are the bacterial species involved in yogurt production
Lactobacillis bulgaricus for flavor/aroma and continues fermentation, Streptococcus thermophilus for texture and initial fermentation
Hot pink color means what in MacConkey agar?
Lactose Fermentation
What are the 3 kind of sugars in TSI?
Lactose-a large amount Sucrose Glucose-a small amount
Phenylalanine Deaminase
Looking for the presents of Phenylpyruvic acid.
Fucus
Looks like a tree with bulbs on the end!
Ulva
Looks like boiled cabbage!
Entamoeba histolyctia
Looks like tissue!
Name at least 2-3 things that need to do transformation experiment?
Lurea Bertani Medium Agar; Transforamtion solution; heat shock and Ice
Extra credit
Lyme diseases-----Borrelia burgdosferi Anthrax----- Bacillus anthracis Tetanus---- Clostridium tetani Cholera---- Vibrio cholerae Tuberculosis----Mycobacterium tuberculosis Gonorrhea---- Neisseria gonorrheae Syphilis ----Treponema pallidum Strep Throat----Streptococcus pyogenes.
What kind of white blood cells are for the immune system?
Lymphocytes
***Enriched media containing 10% NaCl, which selects for Staphylococcus since Staphylococcus prefer the higher salt concentration, which inhibits most other organisms
M-staphylococcus broth test
What does a red medium indicate in Methyl Red testing?
MR +
What does a yellow to orange medium indicate in Methyl Red testing?
MR -
What is the medium used in Methyl Red?
MR/VP
•Both selective and differential •contains 3 ingredients: Lactose (D); Bile (S); Crystal Violet (S) •Lactose + colonies are PINK •Lactose - colonies are COLORLESS •G-GI pathogens have NO problems growing here
Mac CONKEY AGAR:
clockwise from top: e. coli, e. aerogenes, shigella sonnei, proteus mirabilis. e. coli and e. earogenes produce pink color from acid producing lactose fermentation. p. mirabilis, lactose non-fermenter remains normal color
MacConkey agar
Purpose of the Revolving Nosepiece on Brightfield Microscope
Makes the microscope "parfocal"; allows each of the 4 objective lenses to be turned into position for viewing.
Station 16 Malaria Name of the disease
Malaria
falciparum
Malaria
Purpose of the Mechanical Stage Control Knobs on Brightfield Microscope
Maneuvers slide around to change viewing.
Phenol Red Fermentation
Media : 0.5 % Glucose solution or 0.5% Mannitol broth with indicator phenol red . Procedure : broth is inoculated with test bacteria and incubated at 98F /37C For 24 hours and color noted Theory : Phenol red broth is a test medium to which a carbohydrate like glucose or mannitol is added . Phenol red is red under nuetral pH but tends to turn yellow under acidic condition. Acid production from fermentation of the sugar lowers the pH and medium turns yellow indicating carbohydrate utilization by the bacteria . (A) Gas production also from fermentation can be detected as a bubble in an Inverted Durham's tube inside the broth. (AG)
INDOLE RING TEST media
Media : 1% tryptone broth is used . It contains amino acid tryptophan .
CATALASE TEST MEDIA
Media : Bacteria for this test can be grown on nutrient agar TSA PLATE OR** SLANT and the growth is transferred onto a slide to perform this test.
OXIDASE TEST
Media : Bacteria is grown on Nutrient agar and colonies are picked up with a cotton swab and tested with oxidase reagent . Procedure : Using a sterile swab, remove 2-3 colonies from each culture to be tested and smear on a piece of filter paper. Add a drop of the oxidase (TPD) reagent to each spot. If the organism has OXIDASE ACTIVITY, it will turn PURPLE within 30 seconds.
Kirby Bauer Method
Method that allows the rapid determination of the efficacy of a drug -measure zone of inhibition that results from diffusion of the agent into the medium surrounding the disk
Broth/Incubation
Method used to perform carbohydrate fermentation tests
Stab and Streak
Method used to perform urease test
What is the pH indicator of Methyl Red?
Methyl Red
What is the reagent in the MR test?
Methyl Red
MR/VP stands for:
Methyl Red and Voges-Proskauer Broth
Red tube =+. Acids.
Methyl Red test. Which one is positive? For what is it positive?
What is the reagent for testing Methyl Red?
Methyl Red/8-10 drops
Micrococcus luteus
Micrococcus luteus does not grow in the presence of bile salts and crystal violet. •Mannitol Salt Agar (MSA) Test- Positive growth but non-mannitol fermenters includes: Micrococcus luteus • Blood Agar: Gamma Results, no change of mediums color • Biochemical: Catalase Test = POSITIVE A Positive test is indicated by the production of gas bubbles or the presence of effervescence. STAPHYLOCOCCUS and MICROCOCCUS are examples of genus of catalase-positive bacteria.
Gram + Staphylococci
Most bacteria are prohibited from growth on Mannitol/Salt agar except this one
??
Most people find these bugs tasty when dipped in chocolate.
Bifidobacterium, enterocuccus, lactobacillus (anaerobes) E. coli, enterobacter, citrobacter, proteus (facultative anaerobes)
Mutalistic bacteria
Bacteroides, bifidobacterium, enterococcus, lactobacillus, E. coli, enterobacter, citrobacter, proteus
Mutualistic bacteria of the GI tract
Which 2 genre have mycolic acid in their cell walls?
Mycobacteria (causes TB and leprosy) & Nocardia (causes skin infections)
Acid Fast Bacteria
Mycobacterium smegmatis contains mycolic acid
-divided into major groups according to tissue involved in infection -best known to produce mycotoxins or hallucinogenic compounds -some are dimorphic (exhibit as filamentous organisms in nature and as yeast cells in infected tissues) -major spoilers of fruits, vegetables, and grains
Mycoses
-the asexual spores of the mycotic agents are transmitted thru the air and inhaled by victim (however some agents may be acquired via direct contact) -spores can often develop under low pH, high osmotic conditions, and low moisture content which are normally unfavorable for many bacteria
Mycoses Transmission
NEVER LET MONKEYS EAT BANANAS
NEUTROPHILS LYMPHOCYTES MONOCYTES EOSINOPHILS BASOPHILS
Enterobius vermicularis; egg
Name this organism and its form.
Giardia intestinalis; trophozoite phase
Name this organism.
Trypanosoma brucei
Name this organism.
Station 6 Catalase test Name and activity on the enzyme
Name: Catalase Activity: Breakdown its substrate hydrogen peroxides into the water and oxygen gas
These worms "hook" onto your clothing so they can be distributed around the country.
Necator americanus & Ancylostoma duodenale
Mycobacterium
Neg or variable for Gram Rxn-unique cell wal
A green result in a citrate test indicates:
Negative
A solid result for a gelatin test indicates:
Negative
A yellow or orange result for the MR test indicates:
Negative
In a Coagulase Slide test, no clumping indicates:
Negative
In a Coagulase Tube test, a liquid medium indicates:
Negative
No bubbles present in a catalase test indicate:
Negative
No change to the medium in a Bile Esculin Test indicates:
Negative
No color change or copper in the result for VP indicates:
Negative
No color within 20 sec. on an oxidase test is indicative of:
Negative (Cytochrome c oxidase absent)
In a SIM test, no color change of the medium indicates:
Negative (No sulfur reduction)
A yellow result for a urea test indicates:
Negative (urease)
In a SIM test, no radiating growth from the stab line indicates:
Negative motility
Fastidious Bacteria
Neisseria & Haemophilus
Station 11 Parasitic worms Phylum
Nema Toda
Station 11 Parasitic worms Class
Nema Todes
What are the 3 classes of Helminths?
Nematodes Trematodes Cestodes
What is name for a condition with a lot of Neutrophil in the blood?
Neutrophilia
Granulocytes
Neutrophils Eosinophils Basophils
What kind of white blood cells are the most abundant?
Neutrophils (increase during bacterial infection)
INDOLE RING TEST
Next day, Kovac's reagent (p-dimethylaminobenzaldehyde) is added to a broth with indole in it, a dark pink ring develops on top of the tube due to enzyme POSITIVE tryptophanase activity.
What are the reagents in a nitrate test?
Nitrate Reagent A Nitrate Reagent B
Station 9 Citrate test Reagents added after incubation
No
can any chemical completely kill all of the microbes in the area where it is applied?
No
Station 6 Catalase test Negative result:
No bubbles.
Station 13 Casease test Negative result:
No clearing around the growth
Sugar fermentation: Negative result, Positive result, media used & reageant added
No color change and no gas released, gas released and color changes, liquid broth, phenol red
What occurs in γ-hemolysis?
No destruction of RBCs
In a TSIA slant, a red slant/red butt indicates:
No fermentation, utilization of animal proteins, alkaline medium
What would happen if we had a plate that had ampicillin and broth to enhance culture, but the sample did not have pGLO
No grow and no glow
Station 12 Starch test Negative test
No growth around clearing.
Starch hydrolysis: Negative result, Positive result, media used & reageant added
No halo/agar plate remains all blak, clear zone/halo forms around bacteria, starch plate, special iodine
Gelatin hydrolysis: Negative result, Positive result, media used
No liquid formation, liquid formation (gelatinase forms), semi-solid medium
Hydrogen Sulfide Production "Triple Sugar Iron Agar" Negative
No precipitation
Station 3 Indole test Negative result:
No red/ pink ring on top. No color change.
Are endospores a means of reproduction?
No, but are survival dispersal stages of the bacteria allowing them to survive a long time outside of their required living conditions.
To identify the source of gas in a nitrate test, the organism must be a known:
Non-fermenter
MAC agar - LF examples
Normal flora - E.coli and Enterobacter "coliform"
Tests if a bacteria can use glucose in an oxidative (aerobic) or fermentative (anaerobic) condition.
OF Glucose test
Yellow
OF Glucose tube turns ______ if glucose is being used under aerobic or anaerobic conditions
One use of the test is for the preliminary identification of Psedumonas (LACTOSE NEG.) species, which are both oxidase positive and gram-negative.
OXIDASE TEST:Citrate agar is inoculated with Salmonella typhimurium , the medium turns royal blue. This is a positive result for the citrate test.
In a TSIA slant, a red slant/NC butt indicates:
Obligate aerobe, utilization of animal proteins in presence of oxygen, alkaline slant
Red
On SS Agar, all lactose positve colonies appear which color?
