MT AAB STUDY GUIDE TEST
QUESTIONS WITH CORRECT ANSWERS
Methods of testing for the production of beta-lactamase? - Answer-Chromogenic
cephalosporin method, acidometric method, and idiometric method.
What indicates a positive reaction for the beta-lactamase chromogenic cephalosporin
method? - Answer-Color change
Which of the following tests can give a presumptive identification of Moraxella
catarrhalis if the isolate is a Gram-negative diplococci that is oxidase positive and
isolated from a body fluid from the middle ear? - Answer-Beta-lactamase test
What is the morphology of C. diphtheriae - Answer-Gram-positive, non-motile rods
The terms "picket fence" and "Chinese letters" describe the common arrangement of
cells for which organism? - Answer-Corynebacterium
Babes-Ernst granules are characteristic of which organism? - Answer-Corynebacterium
diphtheriae
What is the purpose of potassium tellurite in tellurite medium? - Answer-Inhibits normal
flora
Potassium tellurite medium produces what color colonies of C. diphtheriae - Answer-
Gray-black
When culturing C. diphtheriae, which of the following media will enhance pleomorphism
and granule production? - Answer-Loeffler serum agar
The Elek test is for the detection of which toxin? - Answer-C. diphtheriae toxin
Which of the following diphtheroids is normal flora in the throat? - Answer-
Corynebacterium pseudodiphtheriticum
How long does the morphological cycle of Rhodococcus equi from coccoid to rod form
take? - Answer-24 hours
Which of the following is a Gram-positive to Gram-variable coccobacillus? - Answer-
Listeria monocytogenes
Refrigeration of the specimen for several months may enhance isolation of which
organism? - Answer-Listeria monocytogenes
,Listeria monocytogenes produces a positive in which one of the following biochemical
tests? - Answer-Catalase
Listeria monocytogenes is negative for these biochemical tests? - Answer-Coagulase,
beta-lactamase, and the lactose fermentation test.
Which of the following will differentiate Listeria monocytogenes from Corynebacteria
species? - Answer-Nonmotile and salicin negative
Spore-forming cells in bamboo pole arrangement are characteristic of which organism?
- Answer-Bacillus anthracis
Which aerobic, Gram-positive, sporulating rod can cause food poisoning? - Answer-
Bacillus cereus
Which one of the following will stain acid-fast bacilli? - Answer-Kinyoun stain
What is the function of N-acetyl-L-cysteine-NaOH? - Answer-Liquefy mucus and control
contaminants
How should mycobacterial cultures be incubated? - Answer-In 5% CO2
Which of the following media is clear so that colonies of mycobacteria can be examined
microscopically? - Answer-Middlebrook 7H11
What are some methods for identification of mycobateria? - Answer-Biochemical
reactions, pigment production, and growth rate. NOT spore formation!
What color is a negative enzymatic hydrolysis Tween 80 test? - Answer-Amber
How is Mycobacterium tuberculosis best differentiated from Mycobacterium bovis? -
Answer-Niacin and nitrate tests (M. bovis is nitrite and niacin negative)
A slow-growing, unbranched, acid-fast bacilli that is nitrate negative and niacin negative
is most likely which organism? - Answer-Mycobacterium bovis
Which differential test for identifying the species of mycobacterium spits phenolphthalein
from tripostassium phenolphthalein-sulfate within 2-3 days? - Answer-Arylsulfatase test
One tube of Lowentein-Jensen medium is incubated covered with foil, and one tube is
incubated uncovered. When is the covered tube observed? - Answer-When growth
appears in the uncovered tube.
Which of the following organisms belong to Group IV (rapid growers)? - Answer-
Mycobacterium phlei, Mycobacterium fortuitum, and Mycobacterium smegmatis. (NOT
Mycobacterium gordonae)
,Which statement is true concerning acid-fast bacilli from a nasal mucosa specimen? -
Answer-Not a diagnostic characteristic (for Hansen's disease)
What specimen is usually used for the diagnosis of Hansen's disease? - Answer-Tissue
fluid
What are "lepra" cells? - Answer-Macrophages containing acid-fast bacilli
Lumpy jaw is caused by which organism? - Answer-Actinomyces israelii
Which one of the following is anaerobic? - Answer-Actinomyces israelii
Which of the following organisms is urease positive? - Answer-Nocardia is urease
positive.
NOT Salmonella, Moraxella, or Shigella.
Nocardia will grow on any medium that does not contain... - Answer-Antibiotics
A fastidious, small to filamentous, Gram-negative rod from a nasopharyngeal swab is
most likely to be which organism? - Answer-Haemophilus influenzae
Which medium is preferred for the culture of Haemophilus species? - Answer-Enriched
chocolate agar
Cultures of Staphylococcus aureus supply which of the following to cultures of
Haemophilus? - Answer-V factor
Which organism causes whooping cough? - Answer-Bordatella pertussis
What is the preferred method for the isolation of Bordatella pertussis? - Answer-Regan-
Lowe medium
Which of the following species of Bordatella are urease-positive and oxidase-positive? -
Answer-B. parapertussis
A Brucella isolate that does not produce H2S, does not require CO2, and is not inhibited
by thionin or basic fuschin is probably which species of Brucella? - Answer-B. melitensis
A relatively slow growing and fastidious Gram-negative rod that produces a
characteristic brown pigment on Feeley-Gorman iron cysteine agar is most probably
which organism? - Answer-Legionella pneumophila
What is the best medium for the isolation of Legionella? - Answer-Buffered charcoal
yeast extract agar
, Which Gram-negative, fastidious bacillus has been isolated from air-conditioning
towers? - Answer-Legionella pneumophila
Which atmospheric conditions are best for Campylobacter? - Answer-Obligate
microaerophilic
A curved, Gram-negative rod that is nonfermentative, nitrite positive, and
microaerophilic is probably which organism? - Answer-Campylobacter jejuni
A motile, Gram-negative, slender, curved rod that is the cause of enteritis is best
isolated on which agar? - Answer-Campylobacter blood agar
What does the Campy gas mixture consist of? - Answer-5% O2, 10% CO2, 85% N2
Which organism colonizes the human stomach and is associated with peptic ulcer
disease? - Answer-Helicobacter pylori
Clue cells may be found in infections with which organism? - Answer-Gardnerella
vaginalis
What kind of media extends the lag phase of normal flora and decreases the lag phase
of pathogens? - Answer-Enrichment media
Which type of selective media for Salmonella and Shigella uses bromthymol blue and
acid fuschin as indicators? - Answer-Hektoen Enteric (HE) agar
What is the hydrogen sulfide indicator in triple sugar iron agar? - Answer-Sodium
thiosulfate
IMViC is a series of which of the following tests? - Answer-Indole, methyl red, Voges-
Proskauer, and citrate. Which tests for evidence of an enteric bacterium.
What is the indicator in the methyl red test? - Answer-Methyl red
Which pair of organisms can be used for quality control in the Voges-Proskauer test? -
Answer-Enterobacter (positive) and Echerichia (negative)
What is the Voges-Proskauer test? - Answer-VP is a test used to detect acetoin in a
bacterial broth culture. A cherry red color indicates a positive result, while a yellow-
brown color indicates a negative result.
Voges-Proskauer positive organisms? - Answer-Enterobacter, Klebsiella, and Serratia
marcescens
QUESTIONS WITH CORRECT ANSWERS
Methods of testing for the production of beta-lactamase? - Answer-Chromogenic
cephalosporin method, acidometric method, and idiometric method.
What indicates a positive reaction for the beta-lactamase chromogenic cephalosporin
method? - Answer-Color change
Which of the following tests can give a presumptive identification of Moraxella
catarrhalis if the isolate is a Gram-negative diplococci that is oxidase positive and
isolated from a body fluid from the middle ear? - Answer-Beta-lactamase test
What is the morphology of C. diphtheriae - Answer-Gram-positive, non-motile rods
The terms "picket fence" and "Chinese letters" describe the common arrangement of
cells for which organism? - Answer-Corynebacterium
Babes-Ernst granules are characteristic of which organism? - Answer-Corynebacterium
diphtheriae
What is the purpose of potassium tellurite in tellurite medium? - Answer-Inhibits normal
flora
Potassium tellurite medium produces what color colonies of C. diphtheriae - Answer-
Gray-black
When culturing C. diphtheriae, which of the following media will enhance pleomorphism
and granule production? - Answer-Loeffler serum agar
The Elek test is for the detection of which toxin? - Answer-C. diphtheriae toxin
Which of the following diphtheroids is normal flora in the throat? - Answer-
Corynebacterium pseudodiphtheriticum
How long does the morphological cycle of Rhodococcus equi from coccoid to rod form
take? - Answer-24 hours
Which of the following is a Gram-positive to Gram-variable coccobacillus? - Answer-
Listeria monocytogenes
Refrigeration of the specimen for several months may enhance isolation of which
organism? - Answer-Listeria monocytogenes
,Listeria monocytogenes produces a positive in which one of the following biochemical
tests? - Answer-Catalase
Listeria monocytogenes is negative for these biochemical tests? - Answer-Coagulase,
beta-lactamase, and the lactose fermentation test.
Which of the following will differentiate Listeria monocytogenes from Corynebacteria
species? - Answer-Nonmotile and salicin negative
Spore-forming cells in bamboo pole arrangement are characteristic of which organism?
- Answer-Bacillus anthracis
Which aerobic, Gram-positive, sporulating rod can cause food poisoning? - Answer-
Bacillus cereus
Which one of the following will stain acid-fast bacilli? - Answer-Kinyoun stain
What is the function of N-acetyl-L-cysteine-NaOH? - Answer-Liquefy mucus and control
contaminants
How should mycobacterial cultures be incubated? - Answer-In 5% CO2
Which of the following media is clear so that colonies of mycobacteria can be examined
microscopically? - Answer-Middlebrook 7H11
What are some methods for identification of mycobateria? - Answer-Biochemical
reactions, pigment production, and growth rate. NOT spore formation!
What color is a negative enzymatic hydrolysis Tween 80 test? - Answer-Amber
How is Mycobacterium tuberculosis best differentiated from Mycobacterium bovis? -
Answer-Niacin and nitrate tests (M. bovis is nitrite and niacin negative)
A slow-growing, unbranched, acid-fast bacilli that is nitrate negative and niacin negative
is most likely which organism? - Answer-Mycobacterium bovis
Which differential test for identifying the species of mycobacterium spits phenolphthalein
from tripostassium phenolphthalein-sulfate within 2-3 days? - Answer-Arylsulfatase test
One tube of Lowentein-Jensen medium is incubated covered with foil, and one tube is
incubated uncovered. When is the covered tube observed? - Answer-When growth
appears in the uncovered tube.
Which of the following organisms belong to Group IV (rapid growers)? - Answer-
Mycobacterium phlei, Mycobacterium fortuitum, and Mycobacterium smegmatis. (NOT
Mycobacterium gordonae)
,Which statement is true concerning acid-fast bacilli from a nasal mucosa specimen? -
Answer-Not a diagnostic characteristic (for Hansen's disease)
What specimen is usually used for the diagnosis of Hansen's disease? - Answer-Tissue
fluid
What are "lepra" cells? - Answer-Macrophages containing acid-fast bacilli
Lumpy jaw is caused by which organism? - Answer-Actinomyces israelii
Which one of the following is anaerobic? - Answer-Actinomyces israelii
Which of the following organisms is urease positive? - Answer-Nocardia is urease
positive.
NOT Salmonella, Moraxella, or Shigella.
Nocardia will grow on any medium that does not contain... - Answer-Antibiotics
A fastidious, small to filamentous, Gram-negative rod from a nasopharyngeal swab is
most likely to be which organism? - Answer-Haemophilus influenzae
Which medium is preferred for the culture of Haemophilus species? - Answer-Enriched
chocolate agar
Cultures of Staphylococcus aureus supply which of the following to cultures of
Haemophilus? - Answer-V factor
Which organism causes whooping cough? - Answer-Bordatella pertussis
What is the preferred method for the isolation of Bordatella pertussis? - Answer-Regan-
Lowe medium
Which of the following species of Bordatella are urease-positive and oxidase-positive? -
Answer-B. parapertussis
A Brucella isolate that does not produce H2S, does not require CO2, and is not inhibited
by thionin or basic fuschin is probably which species of Brucella? - Answer-B. melitensis
A relatively slow growing and fastidious Gram-negative rod that produces a
characteristic brown pigment on Feeley-Gorman iron cysteine agar is most probably
which organism? - Answer-Legionella pneumophila
What is the best medium for the isolation of Legionella? - Answer-Buffered charcoal
yeast extract agar
, Which Gram-negative, fastidious bacillus has been isolated from air-conditioning
towers? - Answer-Legionella pneumophila
Which atmospheric conditions are best for Campylobacter? - Answer-Obligate
microaerophilic
A curved, Gram-negative rod that is nonfermentative, nitrite positive, and
microaerophilic is probably which organism? - Answer-Campylobacter jejuni
A motile, Gram-negative, slender, curved rod that is the cause of enteritis is best
isolated on which agar? - Answer-Campylobacter blood agar
What does the Campy gas mixture consist of? - Answer-5% O2, 10% CO2, 85% N2
Which organism colonizes the human stomach and is associated with peptic ulcer
disease? - Answer-Helicobacter pylori
Clue cells may be found in infections with which organism? - Answer-Gardnerella
vaginalis
What kind of media extends the lag phase of normal flora and decreases the lag phase
of pathogens? - Answer-Enrichment media
Which type of selective media for Salmonella and Shigella uses bromthymol blue and
acid fuschin as indicators? - Answer-Hektoen Enteric (HE) agar
What is the hydrogen sulfide indicator in triple sugar iron agar? - Answer-Sodium
thiosulfate
IMViC is a series of which of the following tests? - Answer-Indole, methyl red, Voges-
Proskauer, and citrate. Which tests for evidence of an enteric bacterium.
What is the indicator in the methyl red test? - Answer-Methyl red
Which pair of organisms can be used for quality control in the Voges-Proskauer test? -
Answer-Enterobacter (positive) and Echerichia (negative)
What is the Voges-Proskauer test? - Answer-VP is a test used to detect acetoin in a
bacterial broth culture. A cherry red color indicates a positive result, while a yellow-
brown color indicates a negative result.
Voges-Proskauer positive organisms? - Answer-Enterobacter, Klebsiella, and Serratia
marcescens
