Microbiology BOC Practice Questions with Complete Solutions (Latest 2025) Proper media for culture of a urethral discharge from a man
include:
a sheep blood and phenylethyl alcohol agars b eosin- methylene blue and sheep blood agars c thioglycollate broth and chocolate agar d chocolate and modified Thayer-Martin agars - Correct Answers ✅d chocolate and modified Thayer-Martin agars d Chocolate agar and chocolate agar- based selective media should be used for recovery of Neisseria gonorrhoeae from urethral discharge. Chocolate agar provides the nutrients required by N gonorrhoeae and selective media contains antimicrobial agents that inhibits other organisms and permits recovery of pathogenic Neisseria.A sheep blood agar plate inoculated with 0.001mL of urine grows 70 colonies of Staphylococcus aureus. How many colony forming units per mL of urine be reported?a 70 b 700 c 7,000 d 70,000 - Correct Answers ✅d 70,000 d When 0.001 mL of urine is plated, the growth of one colony is equivalent to 1000 CFU/mL. Thus 70 colonies is 70,000 CFU/mL. 1 / 4
Microbiology BOC Practice Questions with Complete Solutions (Latest 2025) The lowest concentration of antibiotic that inhibits growth of
a test that inhibits growth of a test organism is the:
a minimum inhibitory concentration b serum inhibitory concentration c minimum bactericidal titer d maximum inhibitory titer - Correct Answers ✅a minimum inhibitory concentration a The MIC is a basic laboratory measurement of the activity of an antibiotic against an organism. It is the lowest concentration of antibiotic that inhibits visible growth of the organism. It does not represent the concentration of antibiotic that is lethal to the organism.Which of the following clean catch urine culture colony counts indicates the patient likely has a urinary tract infection?a 10^1 CFU/mL b 10^3 CFU/mL c 10^5 CFU/mL d no growth - Correct Answers ✅b 10^3 CFU/mL b Patients with infection often have at least 100,000 bacteria/mL of urine in the bladder. However one third of young women with symptomatic cystitis have less than 2 / 4
Microbiology BOC Practice Questions with Complete Solutions (Latest 2025) 100,000 bacteria/mL of urine. The Infectious Disease Society of America consensus definition of cystitis is greater than or equal to 1,000 CFU/mL of a uropathogen.
The steam autoclave method of sterilization:
a uses 15 lbs of pressure for 15 minutes b utilizes dry heat for 20 minutes c produces a maximum temperature of 100 C d requires a source of ethylene oxide - Correct Answers ✅a uses 15 lbs of pressure for 15 minutes a The traditional gravity displacement steam sterilization cycle is 121°C for 15 minutes at 15 pounds per square inch.Ethylene oxide is an alternative sterilization method.The expected colony count in a suprapubic urine from a
healthy individual is:
a 0 CFU/mL b 100 CFU/mL c 1,000 CFU/mL d 100,000 CFU/mL - Correct Answers ✅a 0 CFU/mL a Urine in the bladder is normally sterile. Suprapubic aspiration removes urine directly from the bladder and yields a specimen free of urethral contamination. 3 / 4
Microbiology BOC Practice Questions with Complete Solutions (Latest 2025) 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):
a nonfermenter b obligate anaerobe c aerobe d facultative anaerobe - Correct Answers ✅d facultative anaerobe d Facultative anaerobes are organisms that can grow under both aerobic and anaerobic conditions.The proper blood-to-broth ratio for blood cultures to reduce
the antibacterial effect of serum in adults is:
a 1:2
b 1:3
c 1:10
d 1:30 - Correct Answers ✅c 1:10 c Human blood contains substances that may inhibit microbial growth. Diluting blood in culture broth reduces the concentration of these substances as well as any antibiotics
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