Chaper 17 micro
Anaerobes
Able to Replicate in the absence of oxygen. Differ in response to oxygen
Actinomycosis
Actinomycetes wsp
An organism that can live in reduce concentration of oxygen but prefers an anaerobic environment is known as
Aerotolrent
What is the criteria for sputum acceptability?
An acceptable specimen has more than 25 leukocytes and fewer than 10 epithelial cells per low power field. 10/25
N. gonorrhea and N. meningitidis
Are fastidious⮚ Require enriched media for optimal recovery⮚ Require iron for growth⮚ Strict human pathogens
N. gonorrhoeae:Clinical Infections in Women
As many as 50% are asymptomatic⬤ Endocervix is most common site of infection⬤ Symptoms (if symptomatic)⮚ Dysuria⮚ Cervical discharge⮚ Lower abdominal pain⬤ Complications⮚ Pelvic inflammatory disease (PID)⮚ Sterility⮚ Ectopic pregnancy⮚ Perihepatitis (Fitz-Hugh-Curtis syndrome)
A 67-year-old male had rheumatic heart disease for thirty years. Three months prior to death he began to have episodes of fever and chills accompanied by signs of worsening congestive heart failure. Splinter hemorrhages and purpuric skin rashes were noted three weeks before death.
Bacteria
Which of the following specimens would be unacceptable for anaerobic cultures
Urethral Swab
Neisseriaceae general characteristics
Canophilic Thrive in O2 Gram negative diplococci Cytochrome oxidase and catalase and catalase positive Grows in humid atmosphere can grow anerobically
Describe the following picture and the next test you would perform after observing this gram stain
Catalase test then a Coagulase Test
One main difference between prokaryotes and eukaryote is
Chromosomes
N. gonorrhoeaeSpecimen Collection and Transport
Clinical specimens⮚ Genital sites• Urethra in males⮞ Collect purulent discharge⮞ If no discharge, insert swab (Dacron or rayon) 2 cm in urethraand slowly rotate.• Endocervix in females Rectal culture⮚ Insert swab 4 to 5 cm into the anal canal⬤ Oral/pharyngeal⬤ Eye⬤ Blood/joint fluids⬤ When possible, the laboratory must be notifiedwhen a sample for gonococcal recovery isexpected
Botulism
Clostridium botulinum
Pseudomembranous colitis
Clostridium difficile
A gram-positive bacillus was isolated for my warm specimen in here the following characteristics double zone of being hemolyzed let the recent positive light pays negative spot in the negative what is the most likely identification of these organism
Clostridium perfringenes
myonecrosis death of muscle tissue
Clostridium perfringens
Tetanus
Clostridium tetani
Obligate aerobes (grows in the presence of oxygen
Code PB3MN Pseudomonas Brucella Bordetella Bacillus Cyrus mycobacterium tuberculosis Nocardia
Obligate anaerobes (no Oxygen)
Code ABC Actinomyces Bactericides Clostridium
Quantitative streak
Colony forming Unit Commonly used for growing an even amount of a pure bacterial culture to determine antibiotic resistance
The three basic shapes of bacteria include all of the following
cocci, spirochetes and bacilli
Obligate strict anaerobes
Cute in the presence of oxygen almost immediately
N. gonorrhea Specimen Collection tubes
Daycron swabs calcium alginate and cotton swabs are inhibitory to N. gonnorrhoeae
Which is the common cause of an UTI
E coli
An elderly wheelchair-bound man had a history of recurrent urinary tract infections he presents with new onset of fever chills and confusion blood cultures were drawn the organism growing was nonhemolytic catalase negative and PRY posit grandstand show gram-positive cocci what is most likely organizing
Enterococcus species
beta hemolysis
complete lysis of red blood cells
Endogenus anaerobes least likely to be involved in cases of bacteremia are
Eubacterium
Neisseriaceae Significance
Exist as usual biota in the upper respiratory andurogenital tracts⮚ Meaning most isolates are considered opportunisticpathogens⮚ N. meningitidis can be commensal inhabitant incarriers
And anaerobic pleomorphic gram-negative bacilli was recovered from a liver masses the special potency anti-microbio disk demonstrated that the organism was vancomycin resistant and Coliston and kanamycin sensitive other results were as follows chartreuse fluorescence Spot Indole positive in lipase positive what is the most likely identification of the organism
Furobactium necrophorum
This image is of a Gram stain prepared from a positive blood culture. Which of the following choices is the MOST appropriate report that the tech should provide to the physician?
Gram cocci in chains
Neisseriaceae
Gram negative cocci, oxidase positive
Growth of the primary human pathogens onselective media, such as modified Thayer-Martin (MTM) or New York city agars, is notconsidered confirmatory.
Gram stain of thecolony, oxidase, and additional laboratory testsmust be performed to confirm identification
Anaerobic infections of exogenous origin are usually caused by
Gram-positive spore forming bacilli belonging to the genies clostridium
Over the course of 1 week, a 6-year-old boy develops 0.5- to 1.0-cm pustules on his face. During the next 2 days, some of the pustules break, forming shallow erosions covered by a honey-colored crust. New lesions then form around the crust. The boy's 40-year-old uncle develops similar lesions after visiting for 1 week during the child's illness. The microbiological examination revealed Gram-positive cocci that were catalase-negative. What is the most likely diagnosis? a/ anthrax b/ impetigo c/ mycobacteriosis of the skin d/ tularemia
Impetigo This grows yellow on a blood agar plate
Over the course of one week a six year old boy developed 0.5 to 1.0 CM posters on his face. During the next two days some of the pussies break for Michello erosions covered by a honey colored crust. New lesions formed around the crust. The boys 40 -year-old uncle develop similar lesions after visiting for one week during the chows units what is the most likely
Impetigo caused by staphylococcus aureus
N. gonorrhoeae:Clinical Infections in Men
Incubation period: 2 to 7 days Transmitted only by intimate sexual contact Asymptomatic gonococcal infection is uncommon. 90% of infected men show symptoms of acute infection. Symptoms - Dysuria, urethral discharge Complications - Epididymitis: inflammation of small coiled tube of testicle - Urethral stricture: narrowing of the urethra - Prostatitis: inflammation of the prostate gland
Explain the two main things we observer on a MacConkey agar
MacConkey agar is a selective and differential medium used to isolate and differentiate Gram-negative bacteria, particularly members of the Enterobacteriaceae family.
isolation streak
Method used to isolate individual cells on an agar plate, which will then multiply into a group of identical bacteria and form a visible colony We use 1+ 3+ and so on
A sputum specimen from a cystic fibrosis patient grew Gram negative rods on sheep blood agar and MacConkey's agar. The organism Gram negative bacillus, motile, non-spore former bacterium, catalase positive, oxidase positive
Most pikely organism is Pseudomonas as it is an oxidase positive, pigment producing, non-fermenting gram-negative bacilli. It is a major pathogen responsible for most of the hospital acquired infections and also of importance in patients with cystic fibrosis
Neisseriaceae Family
Neisseria, Kingella, Eikenella, Simonsiella, Alysiella
gamma hemolysis
No hemolysis, and no change in the blood agar around the colony
Which bacteria cannot growing in the presence of oxygen
Obligate anaerobes
What spot test is the main differentiator between Enterobacterales and non fermenters?
Oxidase test
Most Neisseria species are
Oxidase-positive, gram-negative diplococci in pairs sides flattend
The function of the cell wall is to
Provide rigdety and strength the exterior wall support, protection and shape
The organism MOST LIKELY to infect normal heart valves is:
Staphylococcus aureus
Animal ropes I'm pulling in human medicine because
They can produce serious and often fatal infections and intoxication
The heart valve MOST OFTEN affected by infective endocarditis in IV drug abusers is the:
Tricuspid Valve
Gonorrhea morphology
Urethral discharge of a symptomatic male⮞ Kidney bean-shaped gram-negative intracellular diplococci⮞ When present, 89% likely to be gonococcal infection n women• 50% to 70% correlation of direct Gram stain with culture• Commensal vaginal microbiota resembles gonococci⮚ Discharge in symptomatic women• Gram stain may be helpful• Culture is necessary for confirmation⮚ Gram-stained smear with more than fivepolymorphonuclear neutrophils per field with nobacteria suggests nongonococcal urethritis
N. gonorrhea treatment
a single dose of 500 mg of intramuscular Ceftriaxone
N. gonorrhoeae
always pathogenic
M. catarrhalis is asaccharolytic
and it isdifferentiated from Neisseria spp. by beingtributyrin hydrolysis positive or DNase positive
N.gonorrhea and N meningitides
are primary human pathogens genus
Anaerobic bacteria
bacteria that do not require oxygen to survive
Impetigo-Staphylococcus aureus
bacterial skin infection characterized by isolated pustules that become crusted and rupture
facultative aerobes
can use oxygen or not Aerobic change to anaerobes Lactobacillus
Capnophilic
carbon dioxide loving bacteria Code - BPH Brucella about s Pneumococcus Haemophilus
Pathogenic species are
fastidious organisms requiring enriched and selective media for optimal recovery
Strep pneumoniae
gram positive cocci
Neisseria gonorrhoeae
humans are the only natural host
Growth of the primary human pathogens onselective media, such as modified Thayer-Martin (MTM) or New York city agars,
is notconsidered confirmatory. Gram stain of thecolony, oxidase, and additional laboratory testsmust be performed to confirm identification
The incidence of infections caused bycommensal Neisseria spp
is very low unless found in aspecimen from a normally sterile site and arerarely associated with septicemia andendocarditis.
Initial screening of gram-negative rods is done by testing for the use of this carbohydrate
lactose test
gonorrhea male
male discharge intracellular and extracellular negative diplococci for N. gonorrhea Direct smears with polymorphononuclear nuetrophils
gonnoria meaning
means flow of seed when urethral discharge was mistaking for semen
N. gonnorrhoeae
most common transmitted by sexual contact Asymptomatic carriers must be reported state health laborites
Disease in newborns
occurs vaginal delivery through infected birth canal if not treated can cause blindness Every one must be treated at birth
N. meningitidis
opportunistic invasive pathogen upperrespiratory tract of carriers
All othterm-57er Neisseria species are
opportunistic pathogens and must bedifferentiated from
Facultative anaerobes/aerobes
organisms that can live in the presence or absence of oxygen-they do aerobic cell resp when oxygen is present, and some other energy metabolism when oxygen is absent -nearly all prokaryotes and fungi are in this category do both processes depending on what is availble
Neisseria are
oxidase positive aerobic organisms that grow best in C02
What biochemical tests will differentiate nonfermenters from enterobacterales except plesiomonas
oxidase test
alpha hemolysis
partial hemolysis (green)
Pathogenic species are fastidious organisms
require enriched and selective media for optimal recovery
M.catarrhalis
respiratory infections associated with opportunistic infections including otitis infections media,sinusitis, and lower respiratory infections
gonorrhea culture and media incubation characteristics
selective media inoculated culture at 35 C in 3% to 5% carbon dioxide CO2 incubater Generating pouch⮚ Candle extinction ja
medium is used in the motility test
semi-solid
An elderly wheelchair bound man had a history of recurrent urinary tract infections. He presents with new onset of fever, chills, and confusion. Blood cultures were drawn. The organism grown was non-hemolytic, catalase negative, and PYR positive. Gram stain showed gram positive cocci. What is the most likely organism?
staphylococcus epidermis
Streptococcus pyogenes
strep throat
Some anaerobes are particularly susceptible to oxygen because they lack the enzyme
superoxide dismutase
why is the most cases of salmonella food poisoning are not treated with antibiotics
this disease is self limiting and it will dissolve on its own
N. gonorrhoeaeColony Morphology
⬤ Colony morphology on modified Thayer-Martin(MTM) agar⮚ Small, gray to tan⮚ Translucent, raised42N. gonorrhoeaeColony Morphology
⬤ Colony morphology on modified Thayer-Martin(MTM) agar⮚ Small, gray to tan⮚ Translucent, raised42N. gonorrhoeaeColony Morphology
⬤ Colony morphology on modified Thayer-Martin(MTM) agar⮚ Small, gray to tan⮚ Translucent, raised42N. gonorrhoeaeColony Morphology