BOC MICROBIOLOGY ASSESSMENT TEST
PAPER QUESTIONS AND SOLUTIONS
GRADED A+ FULL REVIEW GUIDE
●● A sheep blood agar plate inoculated with 0.001 mL of urine grows 70
colonies of Staphylococcus aureus. How many colony forming units per
mL of urine should be reported?
70
700
7,000
70,000
Answer: 70,000
●● The lowest concentration of antibiotic that inhibits growth of a test
organism:
Minimum inhibitory concentration
Serum inhibitory concentration
Minimum bactericidal titer
Maximum inhibitory titer
Answer: Minimum inhibitory concentration
,●● Which of the following clean catch urine culture colony counts
indicates the patient likely has a urinary tract infection?
10¹ CFU/mL
10³ CFU/mL
10⁵ CFU/mL
No growth
Answer: 10³ CFU/mL
●● The steam autoclave method of sterilization:
Uses 15 lbs of pressure for 15 minutes
Utilizes dry heat for 20 minutes
Produces a maximum temperature of 100°C
Requires a source of ethylene oxide
Answer: Uses 15 lbs of pressure for 15 minutes
●● The expected colony count in a suprapubic urine from a healthy
individual is:
0 CFU/mL
100 CFU/mL
,1,000 CFU/mL
100,000 CFU/mL
Answer: 0 CFU/mL
●● An aspirate of a deep wound was plated on blood agar plates and
incubated aerobically and anaerobically. At 24 hours there was growth
on both plates. This indicates that the organism is a(n):
Nonfermenter
Obligate anaerobe
Aerobe
Facultative anaerobe
Answer: Facultative anaerobe
●● A penicillin-resistant Neisseria gonorrhoeae produces:
Alpha-hemolysin
Beta-lactamase
Enterotoxin
Coagulase
Answer: Beta-lactamase
, ●● Which selective medium is used for the isolation of gram-positive
microorganisms?
Columbia CNA with 5% sheep blood
Trypticase soy agar with 5% sheep blood
Eosin methylene blue
Modified Thayer-Martin
Answer: Columbia CNA with 5% sheep blood
●● The most sensitive substrate for the detection of beta-lactamase is:
Penicillin
Ampicillin
Cefoxitin
Nitrocefin
Answer: Nitrocefin
●● An Enterococcus isolated from multiple blood cultures in a patient
endocarditis should be:
Screened for high level aminoglycoside resistance
Checked for tolerance
Assayed for serum antimicrobial activity
PAPER QUESTIONS AND SOLUTIONS
GRADED A+ FULL REVIEW GUIDE
●● A sheep blood agar plate inoculated with 0.001 mL of urine grows 70
colonies of Staphylococcus aureus. How many colony forming units per
mL of urine should be reported?
70
700
7,000
70,000
Answer: 70,000
●● The lowest concentration of antibiotic that inhibits growth of a test
organism:
Minimum inhibitory concentration
Serum inhibitory concentration
Minimum bactericidal titer
Maximum inhibitory titer
Answer: Minimum inhibitory concentration
,●● Which of the following clean catch urine culture colony counts
indicates the patient likely has a urinary tract infection?
10¹ CFU/mL
10³ CFU/mL
10⁵ CFU/mL
No growth
Answer: 10³ CFU/mL
●● The steam autoclave method of sterilization:
Uses 15 lbs of pressure for 15 minutes
Utilizes dry heat for 20 minutes
Produces a maximum temperature of 100°C
Requires a source of ethylene oxide
Answer: Uses 15 lbs of pressure for 15 minutes
●● The expected colony count in a suprapubic urine from a healthy
individual is:
0 CFU/mL
100 CFU/mL
,1,000 CFU/mL
100,000 CFU/mL
Answer: 0 CFU/mL
●● An aspirate of a deep wound was plated on blood agar plates and
incubated aerobically and anaerobically. At 24 hours there was growth
on both plates. This indicates that the organism is a(n):
Nonfermenter
Obligate anaerobe
Aerobe
Facultative anaerobe
Answer: Facultative anaerobe
●● A penicillin-resistant Neisseria gonorrhoeae produces:
Alpha-hemolysin
Beta-lactamase
Enterotoxin
Coagulase
Answer: Beta-lactamase
, ●● Which selective medium is used for the isolation of gram-positive
microorganisms?
Columbia CNA with 5% sheep blood
Trypticase soy agar with 5% sheep blood
Eosin methylene blue
Modified Thayer-Martin
Answer: Columbia CNA with 5% sheep blood
●● The most sensitive substrate for the detection of beta-lactamase is:
Penicillin
Ampicillin
Cefoxitin
Nitrocefin
Answer: Nitrocefin
●● An Enterococcus isolated from multiple blood cultures in a patient
endocarditis should be:
Screened for high level aminoglycoside resistance
Checked for tolerance
Assayed for serum antimicrobial activity
