Microbiology Exam Review 3 Ch. 6, 9-13
Penicillin
A gram-negative diplococcus isolated from a nasopharyngeal culture yielded the following results: 2+ small, grayish non-hemolytic colonies on blood agar, 3+ small, tan colonies on chocolate; oxidase positive; glucose and maltose positive; beta-lactamase (cefinase) positive. What antibiotic should definitely NOT be prescribed for this infection? Penicillin Ceftriaxone Spectinomycin Tetracycline
Growth and usually blue color in the medium after 24 hours incubation at 35°C
A positive Simmons citrate test is seen as a: Growth and usually blue color in the medium after 24 hours incubation at 35°C Yellow color in the medium after 24 hours incubation at 35°C Red color in the medium after 18 hours incubation at 35°C Green color in the medium after 18 hours incubation at 35°C
both b and c
A positive citrate test is due to the organism's ability to: break down tryptophan. use citrate as the sole source of carbon. extract nitrogen from ammonium salt as the sole nitrogen source both b and c. all of the above.
E. coli
A positive indole test is most useful in differentiating which lactose fermenting member of the Enterobacteriaceae on our flowchart? Shigella Serratia E. coli Proteus
shows hazy appearance throughout or movement away from a stab
A positive test for motility: turns the motility media blue shows hazy appearance throughout or movement away from a stab appears as a scum on the top of the media will turn blue after the addition of the indicator bromthymol blue
Neisseria lactamica
A technician is reading CTA sugars. The maltose, glucose, and lactose tubes are positive. What organism produces acid in these three tubes? Neisseria lactamica Neisseria meningitidis Neisseria sicca Neisseria gonorrhoeae
beta-galactosidase.
A yellow ONPG test indicates the ability of the organism to produce: beta-galactosidase. beta-galactoside permease. lactase. both a and b.
Blood and cerebrospinal fluid (CSF) culture
A young adult goes to the emergency room complaining of headache, dizziness, stiff neck, and a petechial skin rash. What two tests should the physician immediately perform? Skin scraping and pupil dilation Urine and blood culture Genital and throat culture Blood and cerebrospinal fluid (CSF) culture
The ability to test for Chlamydia trachomatis from the same specimen at the same time
An advantage of molecular assays for Neisseria gonorrhoeae is: -The ability to use these tests for assessing the successfulness of treatment -The ability to detect the capsular antigen in body fluids -The ability to test for Chlamydia trachomatis from the same specimen at the same time -Their role as evidence in medicolegal cases
Report the Gram stain, and follow up with culture.
An endocervical swab was collected from a 26-year-old woman with a purulent discharge. The Gram stain revealed the following: - Many white blood cells (WBCs) - Moderate gram-negative diplococci - Moderate gram-negative coccobacilli - Few yeast Based on these things, what would be the next course of action? Report the isolation of Neisseria gonorrhoeae. Work up the yeast. Request a new specimen; this one is contaminated. Report the Gram stain, and follow up with culture.
E. coli
A gram-negative rod is isolated from the bronchial aspirate of an individual who inhaled a minnow while swimming at Lake of the Ozarks in central Missouri. The organism is oxidase positive. Which of the following organisms identifications is least likely for this isolate? E. coli Aeromonas hydrophila Pseudomonas aeruginosa Burkholderia sp.
Salmonella spp.
A green colony with a black center is isolated on HE agar from a stool specimen. It is most likely which ogranism? Klebsiella pneumoniae Escherichia coli Shigella spp. Salmonella spp.
pure culture.
An important requirement for appropriate inoculum preparation in susceptibility testing includes the use of a(n): pure culture. inoculum that matches the severity of the infection multiple organisms sheep blood
Klebsiella pneumoniae
An organism has the following biochemical reactions...what is the identity of the organism? Lactose fermentation pos H2S negative Indole negative Lysine Decarboxylase positive Urease positive Klebsiella pneumoniae Edwardsiella tarda Salmonella typhi Citrobacter freundii
Citrobacter freundii
An organism has the following biochemical reactions...what is the identity of the organism? Lactose fermentation pos H2S positive Edwardsiella tarda Klebsiella pneumoniae Citrobacter freundii Salmonella typhi
a and c
An oxidase-positive, wrinkled, non-lactose fermenting colony is suspicious for: -the organism that causes glanders -an individual with cystic fibrosis -a potential bioterrorism agent -a and c
RapID NF
Colonies on MacConkey agar are clear and slightly lavender. Oxidase reaction is positive. If you were to perform biochemical kit testing on this organism, what test that we have performed in lab would you use? -RapID NF -API 20E -Tube coagulase -RapID CB
RapID NF
Colonies on MacConkey agar are clear and slightly lavender. Oxidase reaction is positive. If you were to perform biochemical kit testing on this organism, what test that we have performed in lab would you use? RapID NF API 20E Tube coagulase RapID CB
1. Vibrio 2.Legionella 3. Bordetella
Match the bacteria with its corresponding growth media: 1.TCBS 2.BCYE 3.Bordet-Gengou or Regan-Lowe Legionella, Vibrio, Bordetella
1. May smell like bleach, grows into the agar (pits the agar) 2. Colonies look like small, spready dried water droplets 3. Small, tan colonies growing on chocolate agar only 4. Dark purple colonies 5. Pink, wet-looking colonies
Match the following bacteria with the corresponding colony morphology: 1.Eikenella corrodens 2.Capnocytophagia 3.Haemophilus influenzae 4.Chromobacterium 5.Campylobacter -Pink, wet-looking colonies -Dark purple colonies -May smell like bleach, grows into the agar (pits the agar) -Colonies look like small, spready dried water droplets -Small, tan colonies growing on chocolate agar only
2. Extended-spectrum beta lactamase resistant in Enterobacteriaceae
Match the laboratory method with its specific purpose. ESBL screen 1. Beta lactamase production 2. Extended-spectrum beta lactamase resistant in Enterobacteriaceae 3. Carbapenem-Resistant Enterobacteriaceae (CRE) 4. MRSA
4. MRSA
Match the laboratory method with its specific purpose. Cefoxitin disk diffusion screen and oxacillin screening agar 1. Beta lactamase production 2. Extended-spectrum beta lactamase resistant in Enterobacteriaceae 3. Carbapenem-Resistant Enterobacteriaceae (CRE) 4. MRSA
3. Carbapenem-Resistant Enterobacteriaceae (CRE)
Match the laboratory method with its specific purpose. Modified Hodge test 1. Beta lactamase production 2. Extended-spectrum beta lactamase resistant in Enterobacteriaceae 3. Carbapenem-Resistant Enterobacteriaceae (CRE) 4. MRSA
1. Beta lactamase production
Match the laboratory method with its specific purpose. Cefinase 1. Beta lactamase production 2. Extended-spectrum beta lactamase resistant in Enterobacteriaceae 3. Carbapenem-Resistant Enterobacteriaceae (CRE) 4. MRSA
Pseudomonas.
Not including organisms in the Enterobacteriaceae family (which are the MOST commonly isolated organisms in the micro lab), the second most common gram-negative bacilli encountered in clinical specimens are: Pseudomonas. Vibrio. Burkholderia. Ralstonia.
Acinetobacter spp.
Of the following species, which are widely distributed in nature and hospital environments? Pseudomonas oryzihabitans Bordetella trematum Pseudomonas luteola Acinetobacter spp.
colorless or pale pink
On MacConkey agar, Proteus spp. would appear green colorless or pale pink yellow red
gram-negative diplococci.
Organisms belonging to the genus Neisseria are: gram-negative diplococci. gram-positive diplococci. gram-negative bacilli. gram-negative coccobacilli.
The bathtub used to debride her wounds.
The second- and third-degree burns of a firefighter become infected with Pseudomonas aeruginosa while she is hospitalized in the burn unit. What is the most likely environmental source for this organism? Her blood pressure cuff. The bathtub used to debride her wounds. Fresh flowers received from her family. Her gastrointestinal tract.
Vibrio
The selective medium, thiosulfate citrate bile salts sucrose (TCBS) agar, is especially formulated for isolating what pathogen from stool cultures? Plesiomonas Salmonella Vibrio Shigella
detects free coagulase.(extracellular proteins)
The tube coagulase test: requires citrated reagent serum detects free coagulase.(extracellular proteins) is performed on slide coagulase-positive isolates to confirm a positive result. detects bound coagulase.
has a Gram positive spectrum, including MRSA, coagulase negative staphylococcus infections and Clostridium difficile colitis.
Vancomycin: -has a Gram positive spectrum, including MRSA, coagulase negative staphylococcus infections and Clostridium difficile colitis. -inhibits protein synthesis. -inhibits DNA gyrase activity -is effective against anaerobes and intracellular pathoge
Burkholderia cepacia
Which organism is often isolated in the sputum of patients with cystic fibrosis? Bordetella trematum Stenotrophomonas maltophilia Acinetobacter spp. Burkholderia cepacia
Acinetobacter
Which organism is oxidase-negative, oxidizes glucose, and is a nonlactose fermenter? Escherichia Acinetobacter Pseudomonas Moraxella
Nystatin inhibits fungi and molds
Which statement correctly describes the mode of action of the antibiotic listed for modified Thayer-Martin medium? Nystatin inhibits fungi and molds Trimothoprim inhibits gram-positive bacteria Colistin inhibits gram-positive bacteria Vancomycin inhibits gram-negative bacteria
Positive Hodge test
A "cloverleaf" pattern of growth around the -penem disk shows a: Positive Hodge test Negative Hodge test
are adequate to presumptively identify the organisms as Pseudomonas aeruginosa
A 23-year-old male develops folliculitis after spending the afternoon in the hot tub at a ski resort. The ski resort physician submits a swab of the pustular discharge for culture. The organism isolated grew as an oxidase-positive, non-lactose fermenter. It is beta-hemolytic on sheep blood agar with a cyan-colored pigment in the surrounding medium and emits a fruity odor. These culture results: -are adequate to presumptively identify the organisms as Pseudomonas aeruginosa -require additional biochemical testing to definitively identify the organism -are not needed because the organism is an environmental contaminant -also require viewing the organism under an ultraviolet light
aerosols of soil and water while serving in Vietnam
A 69-year-old retired army general develops pneumonia after his diagnosis of chronic lymphocytic leukemia. The organism isolated in his sputum culture is an oxidase-positive,wrinkled, non-lactose fermenter with a musty odor that is arginine positive. He probably acquired this organism from: aerosols of soil and water while serving in Vietnam his pet horse the hospital environment his normal upper respiratory flora
Carbapenemase
A Modified Hodge test is performed to test the production of: Beta-Lactamase Carbapenemase H2S Aminoglycosidase
0.5
A bacterial suspension of 1.5 x 108 colony-forming units (CFUs)mL is comparable with which standard inoculum? 0.5 1.0 1.5 2.0
Oxidase, triple sugar iron (TSI) slant, growth at 42° C on Mueller-Hinton agar or trypticase soy agar
A convenient and reliable identification scheme for Pseudomonas aeruginosa involves which of the following conventional tests? Catalase, TSI slant, growth at 42° C on sheep blood agar or trypticase soy agar Oxidase, TSI slant, growth at 24° C on Mueller-Hinton agar or trypticase soy agar Oxidase, triple sugar iron (TSI) slant, growth at 42° C on Mueller-Hinton agar or trypticase soy agar Catalase, lysine iron agar (LIA) slant, growth at 42° C on Mueller-Hinton agar or trypticase soy agar
No discrepancy is present. N. sicca does not grow on MTM agar.
A gram-negative diplococcus grew on 5% sheep blood agar and chocolate agar, had no growth on MacConkey agar, and had no growth on modified Thayer-Martin (MTM) agar. The organism was identified as N. sicca. Which one of the following statements explains the discrepancy of the results obtained on the MTM agar? -The organism was most likely incorrectly transported. -The medium was most likely expired. -No discrepancy is present. N. sicca does not grow on MTM agar. -The organism was most likely incubated at 35° C instead of 25° C.
Acinetobacter baumannii
A patient in the intensive care unit has developed pneumonia. A sputum culture grows an oxidase-negative, non-lactose fermenter. The organism is demonstrated in the Gram stain above. The microbiologist works up the organism as a member of the Enterobacteriaceae. The next day she realizes her error. The organism displays the following results: TSI: K/NC Motility: negative OF medium: open tubes: glucose: yellow, lactose: yellow, maltose: green closed tubes: glucose: green, lactose: green, maltose: green
purple
A positive decarboxylase test tube is the color: pink purple yellow black
Performing an oxidase test from colonies on MacConkey agar may show a false negative result
A sputum culture shows 4+ clear, slightly purple colonies on MacConkey. You perform an oxidase test from the MacConkey agar colonies. The test is negative. The API test is inconclusive. What could be the reason for this discrepancy? Performing an oxidase test from colonies on MacConkey agar may show a false negative result The bacteria growing on the MacConkey is a gram negative diplococci The bacteria growing on the MacConkey is indole positive, not oxidase positive An API test cannot be performed on colonies from MacConkey agar
TCBS agar
A visitor to South American who returned with diarrhea is suspected of being infected with V. cholerae. Select the best medium for recovery and identification of this organism. MacConkey agar TCBS agar XLD agar Blood agar
The Colistin and the Naladixic Acid antibiotics in the CNA agar will interfere with the sensitivity testing. Sub a single Enterococcus colony from the CNA to a blood plate. Perform sensitivity testing the next day from the blood plate.
A wound culture is planted on chocolate, blood, MAC and CNA. All plates but the CNA are covered in a spready Pseudomonas. You have a PYR positive Enterococcus growing on your CNA. What is your next step? -Perform sensitivity testing on the Enterococcus on the CNA. -The Colistin and the Naladixic Acid antibiotics in the CNA agar will interfere with the sensitivity testing. Sub a single Enterococcus colony from the CNA to a blood plate. Perform sensitivity testing the next day from the blood plate. -Enterococcus is not a pathogen, so no need to work up. -Use a sweep of whatever is growing on the blood plate to do the sensitivity testing - it doesn't matter if it's a pure culture.
False
Acinetobacter sp. are oxidase positive and nonmotile.
True
Acyclovir is an anti-viral agent.
Glucose fermentation: Aeromonas is positive for glucose fermentation (A/A).
Aeromonas can be differentiated from Pseudomonas by: -Glucose fermentation: Aeromonas is positive for glucose fermentation (A/A). -Glucose fermentation: Aeromonas can only oxidize glucose (A/N) -Aeromonas is oxidase negative -Aeromonas is halophilic
chloramphenicol
All of the following antibiotics inhibit cell wall formation except: cephalosporins vancomycin chloramphenicol penicillin
cefoxitin
All of the following antibiotics inhibit protein synthesis except: cefoxitin erythromycin tetracycline chloroamphenicol
Report the Gram stain, and follow up with culture
An endocervical swab was collected from a 26-year-old woman with a purulent discharge. The Gram stain revealed the following: - Many white blood cells (WBCs) - Moderate gram-negative diplococci - Moderate gram-negative coccobacilli - Few yeast Based on these things, what would be the next course of action?
Penicillin G
An example of a narrow spectrum antibiotic that inhibits cell wall formation is: tobramycin erythromycin penicillin G amoxicillin
false
An example of intrinsic resistance is the emergence of MRSA.
pure culture.
An important requirement for appropriate inoculum preparation in susceptibility testing includes the use of a(n): single isolated colony. variety of colony types. inoculum that matches the severity of the infection. pure culture.
true
Antibiotic dilution susceptibility testing methods include both manual and automated methods.
bacteriostatic.
Antimicrobial agents that inhibit bacterial growth but generally do not kill the organism are known as: bactericidal. antibiotic. bacteriostatic antagonistic.
bactericidal
Antimicrobial agents that usually kill target organisms are said to be: bactericidal. antibiotic. bacteriostatic. antagonistic.
intrinsic
Antimicrobial resistance resulting from the normal genetic, structural, or physiologic state of a microorganism is referred to as __________ resistance. intrinsic inherent microorganism-mediated clinical
tobramycin and gentamycin
Because of narrow therapeutic index and toxicity concerns, peak and trough levels must be performed when administering: tetracycline and gentamycin vancomycin and amoxicillin tobramycin and gentamycin rifampin and chloroamphenicol
an enzyme produced by bacteria to destroy the beta-lactam ring in certain types of antibiotics
Beta-lactamase is: -a form of MIC susceptibility testing -an enzyme produced by bacteria to destroy the beta-lactam ring in certain types of antibiotics -an exotoxin produced by bacteria to invade intestinal wall cells -a specific type of plasmid that transfers antibiotic resistance between cells
Y. enterocolitica
CIN agar is used to isolate... Salmonella paratyphi Y. enterocolitica Hafnia alvei Enterotoxigenic E. coli
a and b
Commercial identification systems may have problems with the identification of non-fermenting gram-negative rods because: -some of these organisms are slow growing -their biochemical reactions tend to be weak -they are not frequently isolated -a and b -b and c
False
Cotton swabs are preferred for the collection and transport of specimens to be cultured for Neisseria gonorrhoeae.
tyrosine
Decarboxylase tests exist for all the following amino acids EXCEPT: lysine tyrosine ornithine arginine
Amines or diamines and CO2
Decarboxylation of the amino acids lysine, ornithine, and arginine results in the formation of: Ammonia CO2 Amines or diamines and CO2 Urea
the oxidase test.
Differentiation of Stenotrophomonas maltophilia and Burkholderia cepacia is best accomplished by: the oxidase test. nitrate reduction. tyrosine-enriched heart infusion agar. maltose and glucose medium.
Lactose fermentation positive H2S negative Indole negative lysine decarboxylase positive urease negative
From our flow chart, put the following tests in order from top to bottom in identifying E. aerogenes.
lactose fermentation negative H2S negative H2S negative Citrate positive
From our flowchart, put the following tests in order from top to bottom to identify Serratia marcescens.
VP and Citrate
From our flowchart, which is the best test to differentiate Serratia marcescens from other H2S negative non-lactose fermenters? VP and Citrate urease and indole VP and MR VP and urease
lysine decarboxylase
From our flowchart, which is the best test to differentiate the Enterobacter sp. from each other? urease lysine decarboxylase VP indole
Uterus
Gonococcal infections occur primarily in all the following sites EXCEPT: Uterus Endocervix Anal canal Urethra
Neisseria gonorrhoeae.
Gram-negative diplococci are isolated from a genital specimen and yield the following results: - Glucose: positive - Maltose: negative - Lactose: negative The organism can be identifed as: Neisseria lactamica. Moraxella catarrhalis. Neisseria gonorrhoeae. Neisseria meningitidis.
Neisseria gonorrhoeae.
Gram-negative diplococci are isolated from a genital specimen and yield the following results: - Glucose: positive - Maltose: negative - Lactose: negative The organism can be identifed as: Neisseria meningitidis. Moraxella catarrhalis. Neisseria lactamica. Neisseria gonorrhoeae.
Report amount of gram-negative diplococci (few, moderate, many) and estimate the number of neutrophils present.
Gram-negative diplococci are observed on a gram stained smear prepared from a female endocervical genital tract specimen. Which of the following is the most appropriate action? -Report "Neisseria gonorrhoeae isolated," and perform susceptibility testing. -Report "Normal flora isolated," and discard specimen. -Plate specimen on blood agar. -Report amount of gram-negative diplococci (few, moderate, many) and estimate the number of neutrophils present.
Neisseria genus only; further testing would need to be done to speciate.
Gram-negative diplococci recovered from an MTM plate and giving positive oxidase test can be presumptively identified as: -Neisseria gonorrhoeae -Neisseria meningitidis -Neisseria lactamica -Neisseria genus only; further testing would need to be done to speciate.
sexual contact
How are Neisseria gonorrhoeae infections transmitted? Respiratory droplet Contaminated food Spores Sexual contact
Respiratory droplets
How is Neisseria meningitidis spread? Contaminated food Airborne Respiratory droplets Bloodborne
Many polymorphonuclear WBCs, many gram-negative diplococci, intra- and extracellular.
If a male is infected with Neisseria gonorrhoeae, what would be the results of a Gram stain of purulent discharge from his urethra? -Many mononuclear white blood cells, gram-negative cocci. -Many polymorphonuclear WBCs, many gram-negative diplococci, intra- and extracellular. -Few white blood cells, many red blood cells, and gram-negative rods. -Many polymorphonuclear WBCs, few gram-negative intracellular rods, and gram-negative rods.
true
Important side effects of the aminoglycosides include nephrotoxicity and ototoxicity.The disk diffusion susceptibility test requires that the media has a pH between 7.4 and 7.6.
true
In our flowchart, Indole can differentiate E. coli from E. cloacae.
mueller-hinton agar
In the disk diffusion method of antimicrobial susceptibility testing, what is the standard agar base medium used for testing most bacterial organisms? 5% blood agar Brain-heart infusion broth Mueller-Hinton agar Mueller-Hinton broth
Mueller-Hinton agar
In the disk diffusion method of antimicrobial susceptibility testing, what is the standard agar base medium used for testing most bacterial organisms? 5% blood agar Mueller-Hinton agar Mueller-Hinton broth Brain-heart infusion broth
Cholera toxin (CT)
Profuse watery diarrhea (i.e., "rice water stools"), leading to dramatic fluid loss, severe dehydration, and hypotension that frequently leads to death, is the hallmark of which toxin activity? Toxin A Enteric endotoxin Cholera toxin (CT) Shiga toxin
cystic fibrosis
The isolation of an extremely mucoid, oxidase-positive, non-lactose fermenter from the lower respiratory tract usually correlates with the clinical diagnosis of: melioidosis nothing-it is an environmental contaminant glanders cystic fibrosis
intrinsic and acquired
Microorganisms can exhibit antibiotic resistance due to which of the following? captured only intrinsic and acquired acquired only intrinsic only
Neisseria gonorrhoeae
Modified Thayer Martin (MTM), Martin-Lewis (ML), and New York City (NYC) media were all developed for the selective isolation of which organism? Neisseria gonorrhoeae Neisseria mucosa Neisseria meningitidis Moraxella catarrhalis
gram-negative diplococcus
Moraxella catarrhalis can be described as a: gram-positive diplococcus gram-negative diplococcus gram-negative bacillus gram-negative coccobacillus
oxidase-positive.
Moraxella catarrhalis may be described as: often carrying an antiphagocytic capsule. a major cause of venereal disease. oxidase-positive. a glucose utilizer.
production of DNase.
Moraxella catarrhalis may be differentiated from gonococci and meningococci on the basis of its: growth on nutrient agar at 22° C. reduction of nitrate to nitrate. growth on blood agar at 35° C. production of DNase.
Oxidase, oxidation-fermentation (OF) glucose, motility, pigment production
Presumptive tests used for identification of the Pseudomonas spp are: Growth on MacConkey, EMB, and XLD agars and motility Growth on blood agar plate (BAP) and eosinmethylene blue (EMB) agars, lysine decarboxylation, catalase Oxidase, oxidation-fermentation (OF) glucose, motility, pigment production Growth on mannitol salt agar and flagellar stain
for 48 hours
Prior to adding reagent(s) and interpretation, the conventional methyl red test requires incubation for 24 hours. at 42°C. at 25°C. for 48 hours.
Pseudomonas aeruginosa
Production of exotoxin A and several proteolytic enzymes and hemolysis are factors that contribute to the pathogenicity of which organism? Pseudomonas aeruginosa Burkholderia mallei Ralstonia pickettii Burkholderia cepacia
Burkholderia cepacia complex
Respiratory cultures obtained from an individual with cystic fibrosis should include selective medium for the isolation of: Stenotrophomonas maltophilia Burkholderia pseudomallei Burkholderia cepacia complex Acinetobacter sp.
causes the production of rice water stools
Small comma-shaped, oxidase-positive, gram-negative rods that are susceptible to O/129 and string test positive are characteristic for an organism that: -s able to grow to 42ºC -causes peptic ulcers -causes the production of rice water stools -is part of the normal gut flora of leeches
cell wall synthesis.
Staphylococcus aureus is a gram-positive organism that produces the enzyme beta-lactamase, which renders certain types of antibiotics inactive. The mode of action that is prevented in certain antibiotics sensitive to this enzyme is: -protein synthesis to the 50S ribosomal subunit. -protein synthesis to the 30S ribosomal subunit. -cell wall synthesis. -deoxyribonucleic acid (DNA) synthesis.
oxidation/fermentation
Test requires the addition of parrafin oil to tube to ensure conditions to encourage fermentation before incubation
methyl red/vp
Test to detect the end product of glucose fermentation and requires the addition of these reagents: alpha-naphthol and KOH
ONPG
Test to detect the enzyme beta-galactosidase in fermentation of the sugar
Oxidase
Test to detect the enzyme cytochrome oxidase
Urea
Test to detect the enzyme urease
Phenylalanine deaminase
Test used to detect the end product phyenylpyruvic acid and uses ferric chloride as a reagent
Citrate
Test uses ammonium salts as the sole nitrogen source
Neisseria meningitidis
The bacterial species that can be described as oxidase-positive, glucose-positive, maltose-positive, sucrose-negative, lactose-negative, and a major cause of bacterial meningitis is: Neisseria gonorrhoeae Neisseria flavescens Neisseria lactamica Neisseria meningitidis
Neisseria meningitidis
The bacterial species that can be described as oxidase-positive, glucose-positive, maltose-positive, sucrose-negative, lactose-negative, and a major cause of bacterial meningitis is: Neisseria meningitidis Neisseria lactamica Neisseria flavescens Neisseria gonorrhoeae
cannot ferment the sugars present
The deep or butt reaction of a TSI slant appears red-orange for non-fermenting gram-negative rods because the organisms: oxidize the sugars present cannot ferment the sugars present ferment the sugars present degrade the proteins present
Methyl Red Voges-Proskauer
The detection of stable acid end products or neutral end products (acetoin) is the basis of the __________ test. Methyl Red Voges-Proskauer citrate urease Indole
glucose utilization testing
The differentiation of the similar Moraxella catarrhalis and Neisseria spp can be best accomplished by: the oxidase test glucose utilization testing examination of Gram stain of the colony vancomycin susceptibility testing
Burkholderia pseudomallei
The disease referred to as melioidosis is caused by which one of the following? Burkholderia mallei Pseudomonas aeruginosa Burkholderia pseudomallei Ralstonia pickettii
False
The disk diffusion susceptibility test requires that the media has a pH between 7.4 and 7.6.
Moraxella catarrhalis.
The gram-negative coccus that can be described as oxidase-positive, glucose-negative, maltose-negative, sucrose-negative, lactose-negative, and DNase-positive is: Moraxella catarrhalis. Neisseria cinerea. Neisseria gonorrhoeae. Neisseria meningitidis.
Mueller Hinton agar
The media used for the Kirby Bauer test is: Mueller Hinton agar Blood agar Chocolate agar Nutrient agar
lowest antimicrobial agent concentration that completely inhibits visible bacterial growth.
The minimum inhibitory concentration (MIC) result recorded in antimicrobial testing can be defined as the: maximum concentration of antimicrobial agent that should be used for optimal therapy. minimum concentration of antimicrobial agent that should be used for optimal therapy. lowest antimicrobial agent concentration that completely inhibits visible bacterial growth. highest antimicrobial agent concentration that completely inhibits visible bacterial growth.
natural and hospital environments
The natural habitat of Stenotrophomonas sp. can best be described as the: -gastrointestinal tract of humans and other animals. -natural and hospital environments -mucous membranes of animals. -genitourinary tract of animals.
certain gram-negative organisms.
The oxidase test is used primarily for the identification of.. certain gram-negative organisms. gram-positive organisms. Veillonella species. Micrococcus species.
produce a powerful enterotoxin
The pathogenesis of Vibrio cholerae is related to its ability to: -produce an ammonia cloud for protection -invade tissue with cilia -invade the mucous membranes of the intestine -produce a powerful enterotoxin
determine whether the pathogen is capable of expressing resistance to the potential choices of antimicrobial agents.
The primary goal of antimicrobial susceptibility testing is to: determine whether the pathogen --is capable of expressing resistance to the potential choices of antimicrobial agents. -determine in vivo whether the administered antibiotic is killing the pathogen. -determine the extent of an organism's intrinsic resistance. -identify toxins associated with bacterial pathogens.
determine whether the pathogen is capable of expressing resistance to the potential choices of antimicrobial agents.
The primary goal of antimicrobial susceptibility testing is to: determine whether the pathogen is capable of expressing resistance to the potential choices of antimicrobial agents. determine the extent of an organism's intrinsic resistance. determine in vivo whether the administered antibiotic is killing the pathogen. identify toxins associated with bacterial pathogens.
Conjugation
The process by which bacterial genes are transferred to new bacteria by sex pili is called: Transformation Transduction Conjugation Replication
0.6 mL of 5.0% alpha naphthol and 0.2 mL of 40% KOH.
The proper amount and order of addition of reagent(s) for the test for the VP portion of the MRVP test is 0.2 mL of 5.0% 40% KOH and 0.6 mL of 5.0% alpha naphthol. 0.2 mL of 5.0% alpha naphthol and 0.6 mL of 40% KOH. 0.6 mL of 40% KOH and 0.2 mL of 5.0% alpha-naphthol. 0.6 mL of 5.0% alpha naphthol and 0.2 mL of 40% KOH.
Cefsulodin-irgasan-novobiocin (CIN) agar
This organism, belonging to the family Enterobacteriaceae, grows best at 25° to 30° C. Domestic and wild rats and other animals can carry this organism. What is the medium of choice? Xylose-lysine-deoxycholate (XLD) agar MacConkey agar Cefsulodin-irgasan-novobiocin (CIN) agar Hektoen enteric (HE) agar
phenylalanine deaminase
This test shows a green color when positive: oxidation-fermentation methyl red amino acid decarboxylase phenylalanine deaminase
0.5
What McFarland standard do you use for the Kirby Bauer test? 0.5 1.0 2.0 4.0
Neisseria meningitidis
What Neisseria sp. may be found as part of the transient flora of the upper respiratory tract? Neisseria meningitidis Neisseria sicca Neisseria subflava Neisseria gonorrhoeae
tryptophan
What amino acid is in indole test broth? ornithine arginine tryptophan leucine
Oxidase, TSI (glucose fermentation), nitrate reduction, growth on MacConkey agar
What are the most appropriate screening tests to presumptively differentiate and identify the nonfermentative gram-negative bacilli (NFB) from the Enterobacteriaceae? -Motility, urease, morphology on blood agar -Oxidase, TSI (glucose fermentation), nitrate reduction, growth on MacConkey agar -Oxidase, indole, and growth on blood agar -Catalase, decarboxylation of arginine, growth on blood agar
pink
What color is a positive urease test? green blye pink red
Standardization of the initial inoculum
What is the most important step in setting up the Kirby Bauer test? Standardization of the initial inoculum Lawn streak technique Incubation time Applying the disks
The physican expects the laboratory to affirm or reject the antibiotic choice he made after the lab has a presumptive diagnosis.
What role does the laboratory play in antibiotic selection if the physician has already treated the patient before receiving the culture results? -The physician can treat the patient for bacterial infections without lab data, but if the patient has a fungal infection, the physician relies on the laboratory to tell him if the patient has a fungal infection. -The physican expects the laboratory to affirm or reject the antibiotic choice he made after the lab has a presumptive diagnosis. -The physician has only given the patient antibiotic samples and they will only last for a couple days--until the culture results are ready and a proper prescription can be written. -Physicians will only write antibiotic precriptions for patients who are infected with a large number of bacteria, so the laboratory needs to tell the physician which antibiotic to treat the patient infected with small number of bacteria.
True
When measuring the zones around sulfonamides in disk diffusion susceptibility testing, measure the outer zone of heavy growth.
influenzae
Which Haemophilus species is non-hemolytic and will only grow with both X and V factors present? influenzae haemolyticus parahaemolyticus ducreyi
Capnocytophagia Eikenella corrodens
Which of the following are MOST typical of human bites from normal oral flora? Capnocytophagia Eikenella corrodens Campylobacter jejuni Streptobacillus
None of the above
Which of the following are oxidase negative? Haemophilus influenzae Campylobacter jejuni Aeromonas hydrophilia None of the above
Clear colonies on MacConkey agar
Which of the following characteristics would lead you to suspect the presence of a nonfermenting gram-negative rod? -TSI reaction is K/A -Oxidase negative -Clear colonies on MacConkey agar -Susceptible to multiple antimicrobial agents
Inability to ferment glucose
Which of the following characteristics would lead you to suspect the presence of a nonfermenting gram-negative rod? Oxidase negative Susceptible to multiple antimicrobial agents Inability to ferment glucose TSI reaction is K/A
a and c
Which of the following gram-negative rods is associated with individuals who have cystic fibrosis? -an oxidase-positive, pyocyanin-producing, non-lactose fermenter -an oxidase-negative, non-motile, non-lactose fermenter that is K/NC on TSI -an oxidase-positive, lysine-positive, non-lactose fermenter -a and c -All of the above
Pasteurella multicoda
Which of the following is MOST typical of animal bites? Pasteurella multicoda Capnocytophagia Eikenella corrodens Vibrio cholerae
Pseudomonas aeruginosa
Which of the following is NOT tested for CRE? E. coli Klebsiella pneumoniae Proteus mirabilis Pseudomonas aeruginosa
Acinetobacter baumannii
Which of the following oxidase-negative, non-motile, non-fermenting, gram-negative rods can mimic a late lactose fermenter due to the oxidation of lactose rather than fermtation? Acinetobacter baumannii Burkholderia cepacia complex Achromobacter xylosoxidans Stenotrophomonas maltophilia
A fish hook injury on the hand of a 58-year-old male acquired while on vacation in the Gulf of Mexico.
Which of the following scenarios indicates the potential for the isolation of Vibrio vulnificus? -A 17-year-old female experiencing diarrhea after eating undercooked chicken at a family picnic. -A foot wound from a 7-year-old male acquired while catching frogs in a freshwater stream -A 24-year-old female experiencing massive diarrhea after visiting New Delhi for missionary work. -A fish hook injury on the hand of a 58-year-old male acquired while on vacation in the Gulf of Mexico.
Oxidase
Which of the following tests should be done first in order to differentiate Aeromonas spp from the Enterobacteriaceae? Oxidase Catalase OF glucose Urease
Pseudomonas aeruginosa
Which of these organisms is beta hemolytic? Pseudomonas aeruginosa Acinetobacter lwoffi Burkholderia cepacia Stenotrophomonas maltophilia
V. vulnificus
Which organism appears green on TCBS agar and is halophilic? V. harveyi V. cholerae V. vulnificus V. fluvialis
Burkholderia pseudomallei
Which organism exhibits bipolar staining on the Gram stain, which resembles a "safety-pin" appearance? Pseudomonas aeruginosa The Centers for Disease Control and Prevention (CDC) group Burkholderia pseudomallei Brevundimonas diminuta
Burkholderia pseudomallei
Which organism is associated with immunodeficiency syndromes and melioidosis (a glanders-like disease in Southeast Asia and northern Australia)? Burkholderia pseudomallei Pseudomonas stutzeri Pseudomonas aeruginosa Pseudomonas putida
bacteriostatic
______ refers to those antibiotics that inhibit the bacterial growth, but require the host immune system to kill the microorganism. bacteriostatic antibiotic inhibitor antibiotic enhancer bacteriocidal
Increased white blood cells with a predominance of neutrophils, decreased glucose, and increased protein.
An infant has been diagnosed with bacterial meningitis. Further testing of the spinal fluid would likely indicate: -Increased white blood cells with a predominance of neutrophils, increased glucose, and decreased protein. -Increased white blood cells with a predominance of neutrophils, decreased glucose, and increased protein. -Increased white blood cells with a predominance of lymphocytes, decreased glucose, and increased protein. -Decreased white blood cells, increased protein, and decreased glucose.
Sorbitol (fermentation)
An isolate of E. coli recovered from the stool of a patient with severe bloody diarrhea should be tested for which sugar before sending it to a reference laboratory for serotyping? (Hint: Think SMAC) Raffinose (fermentation) Mannitol (oxidation) Sorbitol (fermentation) Sucrose (fermentation)
Salmonella typhi
An organism has the following biochemical reactions...what is the identity of the organism? Lactose fermentation neg H2S positive Phenylalanine deaminase negative Indole negative Citrobacter freundii Klebsiella pneumoniae Salmonella typhi Edwardsiella tarda
Edwardsiella tarda
An organism has the following biochemical reactions...what is the identity of the organism? Lactose fermentation neg H2S positive Phenylalanine deaminase negative Indole positive Edwardsiella tarda Klebsiella pneumoniae Citrobacter freundii Salmonella typhi
Glucose-negative, maltose-negative, and lactose-negative
An organism isolated from a sputum sample that has a "hockey puck" consistency would have which of the following biochemical profiles? Glucose-positive, maltose-negative, and lactose-negative Glucose-negative, maltose-negative, and lactose-negative Glucose-positive, maltose-positive, and lactose-positive Glucose-positive, maltose-positive, and lactose-negative
negative; positive
An organism that appears red with a black center on XLD agar is lactose-fermenting __________ and H2S-producing __________. negative; positive negative; negative positive; positive positive; negative
Escherichia coli
Enterotoxigenic and enteroinvasive are terms often linked to which of the following bacterial species? Shigella sonnei Yersinia pestis Salmonella enteritidis Escherichia coli
Yellow
Escherichia coli would appear what color on HE agar? Green Yellow with a black center Yellow Green with a black center
yellow
Escherichia coli would appear what color on HE agar? Green with a black center Yellow with a black center Yellow Green
Directly inoculated agar plate in a container which maintains CO2 conditions during transport and incubation OR a non-cotton swab placed in a liquid or semi liquid (gel) transport medium (Amies with or without charcoal)
How should a specimen for Neisseria gonorrhoeae be transported to the laboratory? -Directly inoculated agar plate in a container which maintains CO2 conditions during transport and incubation OR a non-cotton swab placed in a liquid or semi liquid (gel) transport medium (Amies with or without charcoal) -Placed in the paper swab cover and transported to the laboratory at the end of the day. -Placed in a tube of broth and transported to the laboratory immediately. -Placed in a transport tube and transported to the laboratory at the end of the day.
Enterobacteriaceae
In addition to being a group of gram-negative bacteria considered normal flora of the gastrointestinal tract of humans and animals, which one of the following also contains agents of important diseases such as gastroenteritis and enteric fevers, urinary tract infections, and bacterial pneumonia? Enterococcus Enterobacteriaceae Micrococcaceae Neisseriaceae
Ferment glucose, reduce nitrate to nitrite, and are oxidase-negative
In general for the organisms that we are concerned with in this group, the Enterobacteriaceae are gram-negative rods that: Ferment glucose, reduce nitrate to nitrite, and are oxidase-negative Ferment glucose, produce indophenol oxidase, and form gas Ferment lactose and produce indophenol oxidase Ferment lactose and reduce nitrite to nitrogen gas
Ferment glucose, reduce nitrate to nitrite, and are oxidase-negative
In general for the organisms that we are concerned with in this group, the Enterobacteriaceae are gram-negative rods that: Ferment lactose and produce indophenol oxidase Ferment lactose and reduce nitrite to nitrogen gas Ferment glucose, produce indophenol oxidase, and form gas Ferment glucose, reduce nitrate to nitrite, and are oxidase-negative
Ammonia and CO2
In the test for urease production, urea is broken down by urease to form which product? Ammonium citrate Ammonia and CO2 Ammonium oxalate Ammonium nitrate
Spot indole-positive
Most strains of Escherichia coli can be presumptively identified on their appearance on MAC as a lactose fermenter and which test that can be performed directly on the colony at the benchtop without further incubation? Citrate-positive Methyl red-negative Spot indole-positive Urease-positive
Salmonella, Shigella, and Yersinia
Of the possible organisms below, which genera of the Enterobacteriaceae are known to cause diarrhea and are considered enteric pathogens? Salmonella, Shigella, and Yersinia Enterobacter, Citrobacter, and Morganella Enterobacter, Klebsiella, Providencia, and Proteus Pseudomonas, Moraxella, Acinetobacter, and Aeromonas
both tubes
Oxidative/Fermentative (O/F) basal medium is a medium that will test the oxidative and fermentative capabilities of a microbe. The organisms that are able to produce acids from carbs will show yellow color in: the tube open to the air the tube with oil overlay both tubes neither tube
indole
Test uses broth containing tryptophan
carbon dioxide (CO2)
The JEMBEC Transport system for Neisseria spp. provides an atmosphere with increased __________ to keep the organism viable during transport. carbon dioxide (CO2) nitrogen (N2) nitrate (NO3) hydrogen (H2)
Acetoin
The Voges-Proskauer (VP) test detects which of the selections below as one of the end products of glucose fermentation? Nitrite Hydrogen sulfide Acetic acid Acetoin
Yersinia enterocolitica
Three consecutive stool cultures from a 25-year-old male patient produced scant normal fecal flora on MacConkey and Hektoen agars. However, colonies on CIN agar (cefsoludin-irgasan-novobiocin) displayed "bulls-eye" colonies after 48 hours incubation. The patient had been suffering from enterocolitis with fever, diarrhea, and abdominal pain for 2 days. What is the most likely identification of this gram-negative rod? E. coli Proteus mirabilis Klebsiella pneumoniae Yersinia enterocolitica
sucrose, glucose, lactose
What are the sugars present in triple sugar iron (TSI)? lactose, sucrose, raffinose sucrose, glucose, rhamnose sucrose, glucose, lactose mannitol, lactose, arabinose
Opthalmia neonatorum
What disease can newborns acquire through a birth canal infected with Neisseria gonorrhoeae? Opthalmia neonatorum Opthalmitis Blindness Conjunctivitis
Purulent discharge
What is the specimen of choice in males for genital infections? Stool Throat culture Urine Purulent discharge
Moraxella catarrhalis
What organism is a commensal of the upper respiratory tract and has become an opportunistic pathogen causing upper respiratory tract infections in otherwise healthy children and the elderly? Moraxella catarrhalis Neisseria lactamica Neisseria sicca Neisseria gonorrhoeae
The toxins are composed of lipopolysaccharide components of the cell wall.
What statement correctly describes the toxins associated with Neisseria? -The toxins are composed of lipopolysaccharide components of the cell wall. -The toxins are characterized as endotoxins -The toxins are similar to the enzymes of Staph aureus -The toxins are released by the living bacterial cell
Hockey puck colonies
What term is used to describe the colonies of M. catarrhalis on plates? Medusa head colonies Fried egg colonies Hockey puck colonies Coin-like colonies
Dacron
What type of swab should be used for a Neisseriae gonorrhoeae culture? Cotton Calcium alginate Flax Dacron
to create an anaerobic (fermentative) environment
When performing the oxidative/fermentative (O/F) test, one tube is covered with mineral oil and one tube is left uncovered. Why is one tube covered with parafin oil? to create a recutive environment to create an asaccharolytic environment to create an anaerobic (fermentative) environment to create an aerobic (oxidative) environment
Phenylalanine deaminase
Which biochemical test requires the use of 10% ferric chloride to detect a positive reaction? Phenylalanine deaminase Deamination of lysine Urease Citrate
Morganella, Providencia, and Proteus
Which genera are positive for phenylalanine deaminase? Klebsiella and Enterobacter Enterobacter, Escherichia, and Salmonella Morganella, Providencia, and Proteus Proteus, Escherichia, and Shigella
Indole, MR, VP, Citrate and MacConkey agar plates
Which group of tests, along with colonial morphology on primary media (hint: think about the normal plates that we use to isolation gram negative rods), aids most in the rapid identification of the Enterobacteriaceae? Indole, MR, VP, Citrate and MacConkey agar plates Bacitracin, β-lactamase, and BAP agar plate MR and VP, urease and PEA agar plate Phyenylanine deaminase, urease, and PEA agar plate
Indole, MR, VP, Citrate and MacConkey agar plates
Which group of tests, along with colonial morphology on primary media (hint: think about the normal plates that we use to isolation gram negative rods), aids most in the rapid identification of the Enterobacteriaceae? Indole, MR, VP, Citrate and MacConkey agar plates Phyenylanine deaminase, urease, and PEA agar plate Bacitracin, β-lactamase, and BAP agar plate MR and VP, urease and PEA agar plate
deep purple
Which is a positive color for Hippurate hydrolysis production? deep purple tan
blue
Which is a positive color for the Citrate test? blue green
red
Which is a positive color for the Methyl Red test? yellow red
red/pink
Which is a positive color for the VP test? yellow red/pink
purple
Which is a positive color for the oxidase test? white purple
Escherichia coli
Which is correct for the description "acid slant, acid butt, no H2S"? Escherichia coli Pseudomonas spp. Proteus spp. Salmonella spp.
Yersinia, Salmonella, and Shigella
Which of the following genera of the Enterobacteriaceae are considered enteric pathogens? Enterobacter, Providencia, and Proteus Yersinia, Salmonella, and Shigella E. coli, Citrobacter, and Klebsiella Enterobacter, Citrobacter, and Morganella
Neisseria flavescens
Which of the following gram-negative diplococci fail to produce acid from glucose, maltose, lactose, and sucrose; produce yellow-pigmented colonies on blood and nutrient agar, and fail to produce DNase? Neisseria meningitidis Neisseria gonorrhoeae Moraxella catarrhalis Neisseria flavescens
1 and 2
Which of the following reagents are required for testing of nitrate reduction? 1. Alpha-naphthylamine 2. Sulfanilic acid 3. Zinc dust 4. Alpha-naphthol 5. 40% KOH
p-Dimethylamino-benzaldehyde (Kovac's reagent)
Which of the following reagents is added to detect the production of indole? Bromcresol purple Methyl red p-Dimethylamino-benzaldehyde (Kovac's reagent) Cytochrome oxidase
