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GCSU Bachoon Microbiology Test 2 Exam Newest
2026 Test Bank Verified Questions Answers 2026
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 - ANSWER -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 - ANSWER -D
Most strains of Escherichia coli can be presumptively identified on the
basis of which characteristic?
A. Spot indole-positive
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B. Citrate-positive
C. Methyl red-negative
D. Urease-positive - ANSWER -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. - ANSWER -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. - ANSWER -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
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B. Xylose-lysine-deoxycholate (XLD) agar
C. Cefsulodin-irgasan-novobiocin (CIN) agar
D. Hektoen enteric (HE) agar - ANSWER -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 - ANSWER -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 - ANSWER -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 - ANSWER -B
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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 - ANSWER -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 - ANSWER -A
MacConkey-sorbitol agar is useful for detecting pathogenic strains of:
A. Escherichia coli.
B. Shigella spp.
C. Salmonella spp.
D. Vibrio spp. - ANSWER -A
The major etiologic agent of urinary tract infections is:
A. Escherichia coli.
GCSU Bachoon Microbiology Test 2 Exam Newest
2026 Test Bank Verified Questions Answers 2026
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 - ANSWER -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 - ANSWER -D
Most strains of Escherichia coli can be presumptively identified on the
basis of which characteristic?
A. Spot indole-positive
,2|Page
B. Citrate-positive
C. Methyl red-negative
D. Urease-positive - ANSWER -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. - ANSWER -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. - ANSWER -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
,3|Page
B. Xylose-lysine-deoxycholate (XLD) agar
C. Cefsulodin-irgasan-novobiocin (CIN) agar
D. Hektoen enteric (HE) agar - ANSWER -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 - ANSWER -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 - ANSWER -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 - ANSWER -B
, 4|Page
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 - ANSWER -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 - ANSWER -A
MacConkey-sorbitol agar is useful for detecting pathogenic strains of:
A. Escherichia coli.
B. Shigella spp.
C. Salmonella spp.
D. Vibrio spp. - ANSWER -A
The major etiologic agent of urinary tract infections is:
A. Escherichia coli.
