Test bank Microbiology Exam CORRECT
ANSWERS100%
For the most part, all Enterobacteriaceae are positive for which biochemical
reactions?
A. Glucose, oxidase, and catalase
B. Glucose, indole, and oxidase
C. Glucose, reduce nitrates to nitrites, and oxidase
D. Glucose, catalase, and reduce nitrates to nitrites - ---correct answers ---
D
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?
A. Neisseriaceae
B. Micrococcaceae
C. Enterococcus
D. Enterobacteriaceae - ---correct answers ---D
Most strains of Escherichia coli can be presumptively identified on the basis of
which characteristic?
A. Spot indole-positive
B. Citrate-positive
C. Methyl red-negative
,D. Urease-positive - ---correct answers ---A
The swarming gram-negative bacillus that can be presumptively identified on the
basis of a positive indole test is:
A. Klebsiella pneumoniae.
B. Proteus vulgaris.
C. Enterobacter aerogenes.
D. Shigella sonnei. - ---correct answers ---B
A gram-negative bacillus that is hydrogen sulfide (H2S)-positive, citrate-positive,
spot indole-negative, and associated with gastroenteritis in the United States is
most likely:
A. Klebsiella pneumoniae.
B. Proteus vulgaris.
C. Salmonella enteritidis.
D. Shigella sonnei. - ---correct answers ---C
This organism, belonging to the family Enterobacteriaceae, grows best at 25º to 30º
C. Domestic and wild rats and other animals can carry this organism. What is the
medium of choice?
A. MacConkey agar
B. Xylose-lysine-deoxycholate (XLD) agar
C. Cefsulodin-irgasan-novobiocin (CIN) agar
D. Hektoen enteric (HE) agar - ---correct answers ---C
Escherichia coli would appear what color on HE agar?
,A. Green
B. Green with a black center
C. Yellow
D. Yellow with a black center - ---correct answers ---C
Enterotoxigenic and enteroinvasive are terms often linked to which of the
following bacterial species?
A. Escherichia coli
B. Salmonella enteritidis
C. Shigella sonnei
D. Yersinia pestis - ---correct answers ---A
A green colony with a black center is isolated on HE agar from a stool specimen. It
is most likely which organism?
A. Escherichia coli
B. Salmonella spp.
C. Shigella spp.
D. Klebsiella pneumoniae - ---correct answers ---B
Escherichia coli can produce a toxin similar to Shigella dysenteriae and can cause
hemorrhagic colitis. What other organ does it affect?
A. Heart
B. Lungs
C. Liver
D. Kidney - ---correct answers ---D
, Of the following bacterial species, which is associated with a serious diarrheal
illness with high mortality rates among some populations?
A. Escherichia coli
B. Shigella spp.
C. Salmonella spp.
D. Vibrio spp - ---correct answers ---A
MacConkey-sorbitol agar is useful for detecting pathogenic strains of:
A. Escherichia coli.
B. Shigella spp.
C. Salmonella spp.
D. Vibrio spp. - ---correct answers ---A
The major etiologic agent of urinary tract infections is:
A. Escherichia coli.
B. Shigella spp.
C. Salmonella spp.
D. Vibrio spp. - ---correct answers ---A
An organism that appears red with a black center on XLD agar is lactose-_____
and H2S-_____.
A. positive; positive
B. positive; negative
C. negative; positive
D. negative; negative - ---correct answers ---C
ANSWERS100%
For the most part, all Enterobacteriaceae are positive for which biochemical
reactions?
A. Glucose, oxidase, and catalase
B. Glucose, indole, and oxidase
C. Glucose, reduce nitrates to nitrites, and oxidase
D. Glucose, catalase, and reduce nitrates to nitrites - ---correct answers ---
D
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?
A. Neisseriaceae
B. Micrococcaceae
C. Enterococcus
D. Enterobacteriaceae - ---correct answers ---D
Most strains of Escherichia coli can be presumptively identified on the basis of
which characteristic?
A. Spot indole-positive
B. Citrate-positive
C. Methyl red-negative
,D. Urease-positive - ---correct answers ---A
The swarming gram-negative bacillus that can be presumptively identified on the
basis of a positive indole test is:
A. Klebsiella pneumoniae.
B. Proteus vulgaris.
C. Enterobacter aerogenes.
D. Shigella sonnei. - ---correct answers ---B
A gram-negative bacillus that is hydrogen sulfide (H2S)-positive, citrate-positive,
spot indole-negative, and associated with gastroenteritis in the United States is
most likely:
A. Klebsiella pneumoniae.
B. Proteus vulgaris.
C. Salmonella enteritidis.
D. Shigella sonnei. - ---correct answers ---C
This organism, belonging to the family Enterobacteriaceae, grows best at 25º to 30º
C. Domestic and wild rats and other animals can carry this organism. What is the
medium of choice?
A. MacConkey agar
B. Xylose-lysine-deoxycholate (XLD) agar
C. Cefsulodin-irgasan-novobiocin (CIN) agar
D. Hektoen enteric (HE) agar - ---correct answers ---C
Escherichia coli would appear what color on HE agar?
,A. Green
B. Green with a black center
C. Yellow
D. Yellow with a black center - ---correct answers ---C
Enterotoxigenic and enteroinvasive are terms often linked to which of the
following bacterial species?
A. Escherichia coli
B. Salmonella enteritidis
C. Shigella sonnei
D. Yersinia pestis - ---correct answers ---A
A green colony with a black center is isolated on HE agar from a stool specimen. It
is most likely which organism?
A. Escherichia coli
B. Salmonella spp.
C. Shigella spp.
D. Klebsiella pneumoniae - ---correct answers ---B
Escherichia coli can produce a toxin similar to Shigella dysenteriae and can cause
hemorrhagic colitis. What other organ does it affect?
A. Heart
B. Lungs
C. Liver
D. Kidney - ---correct answers ---D
, Of the following bacterial species, which is associated with a serious diarrheal
illness with high mortality rates among some populations?
A. Escherichia coli
B. Shigella spp.
C. Salmonella spp.
D. Vibrio spp - ---correct answers ---A
MacConkey-sorbitol agar is useful for detecting pathogenic strains of:
A. Escherichia coli.
B. Shigella spp.
C. Salmonella spp.
D. Vibrio spp. - ---correct answers ---A
The major etiologic agent of urinary tract infections is:
A. Escherichia coli.
B. Shigella spp.
C. Salmonella spp.
D. Vibrio spp. - ---correct answers ---A
An organism that appears red with a black center on XLD agar is lactose-_____
and H2S-_____.
A. positive; positive
B. positive; negative
C. negative; positive
D. negative; negative - ---correct answers ---C
