BOC MICROBIOLOGY 6TH EDITION
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 - (ANSWER)c
The most appropriate method for collecting a urine specimen from a patient with an indwelling
catheter is:
a. remove the catheter, cut the tip and submit it for culture
b. disconnect the catheter from the bag, and aseptically collect urine from the terminal end of the
catheter
c. asepticaly collect urine directly from the drainage bag
d. aspirate urine aseptically from the catheter bag - (ANSWER)d
Which of the following groups of specimens would be acceptable for anaerobic culture?
a. vaginal swab, eye swab
b. intraoral surface swab, leg swab
c. pleural fluid, brain, brain abscess fluid
d. urine, sputum - (ANSWER)c
Sodium polyanetholsulfonate (SPS) is used as an anticoagulant for blood cultures because it:
a. inactivates penicillin and cephalosporins
b. prevents clumping of red cells
c. inactivates neutrophils and components of serum complement
d. facilitates growth of anaerobes - (ANSWER)c
,The optimal collection of a wound specimen for culture of anaerobic organisms is a:
a. swab of lesion obtained before administration of antibiotics
b. swab of lesion obtained after administration of antibiotics
c. syringe filled with pus, obtained before administration of antibiotics
d. syringe filled with pus, obtained after administration of antibiotics - (ANSWER)c
The MOST important variable in the recovery of organisms in adult patients with bacteremia
(bacterial sepsis) is:
a. subculture of all bottles at day 5 of incubation
b. the recommended volume of blood cultured
c. collection of daily blood cultures set for 3 consecutive days
d. collection of multiple blood culture sets from a single venipuncture - (ANSWER)b
Virus transport medium should contain agents that:
a. enable rapid viral growth during the transport time
b. inhibit bacterial and fungal growth
c. destroy nonpathogenic viruses
d. inhibit complement fixing antibodies - (ANSWER)b
A bronchoscopy sample with the request for culture of Legionella is sent to the laboratory. The
correct plating protocol is:
a. culture on thiosulfate citrate bile salt media
b. incubate the culture media anaerobically
c. reject the specimen and request a sputum sample
d. culture of buffered charcoal yeast extract agar with antibiotics - (ANSWER)d
A community hospital microbiology laboratory is processing significant numbers of stool
cultures because of an outbreak of diarrhea following heavy rains and flooding in the county. A
media that should be incorporated in the plating protocol is:
a. colistin nalidixic acid for Listeria
,b. MacConkey agar with sorbitol for Camplobacter
c. mannitol salt agar for Enterococcus species
d. thiosulfate citrate bile salts sucrose for Vibrio species - (ANSWER)d
A male urethral discharge specimen submitted for culture should be innoculated to:
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 - (ANSWER)d
The steam autoclave method of sterilization requires:
a. 15 lb of pressure for 15 minutes
b. dry heat for 20 minutes
c. a maximum temperature of 100 degrees C
d. a source of ethylene oxide - (ANSWER)a
Which selective medium is used for the isolation of gram-positive microorganisms?
a Columbia CNA with 5% sheep blood
b trypticase soy agar with 5% sheep blood
c eosin methylene blue
d modified Thayer-Martin - (ANSWER)a
Camplyobacter jejuni isolation requires the fecal specimen to be:
a. Inoculated onto selective plating media and incubated in reduced oxygen with added CO2 at
42 degrees C
b. stored in tryptic soy broth before plating to ensure growth of organism
c. inoculated onto selective plating media and incubated at both 35 degrees C and at room
temperature
, d. incubated at 35 degrees C for 2 hours in Cary-Blair media before inoculating onto selective
plating media - (ANSWER)a
Which of the following specimen requests is acceptable?
a. feces submitted for anaerobe culture
b. Foley catheter tip submitted for aerobic culture
c. rectal swab submitted for direct smear for gonococci
d. urine for culture of acid-fast bacilli - (ANSWER)d
A CSF specimen containing only 2 drops of CSF was collected by lumbar puncture from a
febrile 25-year old male and was submitted for a stat gram stain and culture. The direct specimen
Gram stain was reported as many neutrophils and no microorganism seen. The remain drop of
CSF should be inoculated to:
a. blood agar
b. CNA agar
c. chocolate agar
d. Thayer-Martin agar - (ANSWER)c
A diabetic foot swab from an 82 year old woman with recurrent infections is submitted for
culture. The gram stain reveals:
Many neutrophils, no squamous epithelial cells
Many Gram-negative bacilli
Many Gram-positive cocci in chains
The physician requests that all pathogens be worked up. In addition to the sheep blood, chocolate
and MacConkey agar plates routinely used for wound cultures, the technologist might also
process an:
a. anaerobic blood agar plate
b. BCYE agar plate
c. CNA agar plate
d. XLD agar plate - (ANSWER)c
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 - (ANSWER)c
The most appropriate method for collecting a urine specimen from a patient with an indwelling
catheter is:
a. remove the catheter, cut the tip and submit it for culture
b. disconnect the catheter from the bag, and aseptically collect urine from the terminal end of the
catheter
c. asepticaly collect urine directly from the drainage bag
d. aspirate urine aseptically from the catheter bag - (ANSWER)d
Which of the following groups of specimens would be acceptable for anaerobic culture?
a. vaginal swab, eye swab
b. intraoral surface swab, leg swab
c. pleural fluid, brain, brain abscess fluid
d. urine, sputum - (ANSWER)c
Sodium polyanetholsulfonate (SPS) is used as an anticoagulant for blood cultures because it:
a. inactivates penicillin and cephalosporins
b. prevents clumping of red cells
c. inactivates neutrophils and components of serum complement
d. facilitates growth of anaerobes - (ANSWER)c
,The optimal collection of a wound specimen for culture of anaerobic organisms is a:
a. swab of lesion obtained before administration of antibiotics
b. swab of lesion obtained after administration of antibiotics
c. syringe filled with pus, obtained before administration of antibiotics
d. syringe filled with pus, obtained after administration of antibiotics - (ANSWER)c
The MOST important variable in the recovery of organisms in adult patients with bacteremia
(bacterial sepsis) is:
a. subculture of all bottles at day 5 of incubation
b. the recommended volume of blood cultured
c. collection of daily blood cultures set for 3 consecutive days
d. collection of multiple blood culture sets from a single venipuncture - (ANSWER)b
Virus transport medium should contain agents that:
a. enable rapid viral growth during the transport time
b. inhibit bacterial and fungal growth
c. destroy nonpathogenic viruses
d. inhibit complement fixing antibodies - (ANSWER)b
A bronchoscopy sample with the request for culture of Legionella is sent to the laboratory. The
correct plating protocol is:
a. culture on thiosulfate citrate bile salt media
b. incubate the culture media anaerobically
c. reject the specimen and request a sputum sample
d. culture of buffered charcoal yeast extract agar with antibiotics - (ANSWER)d
A community hospital microbiology laboratory is processing significant numbers of stool
cultures because of an outbreak of diarrhea following heavy rains and flooding in the county. A
media that should be incorporated in the plating protocol is:
a. colistin nalidixic acid for Listeria
,b. MacConkey agar with sorbitol for Camplobacter
c. mannitol salt agar for Enterococcus species
d. thiosulfate citrate bile salts sucrose for Vibrio species - (ANSWER)d
A male urethral discharge specimen submitted for culture should be innoculated to:
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 - (ANSWER)d
The steam autoclave method of sterilization requires:
a. 15 lb of pressure for 15 minutes
b. dry heat for 20 minutes
c. a maximum temperature of 100 degrees C
d. a source of ethylene oxide - (ANSWER)a
Which selective medium is used for the isolation of gram-positive microorganisms?
a Columbia CNA with 5% sheep blood
b trypticase soy agar with 5% sheep blood
c eosin methylene blue
d modified Thayer-Martin - (ANSWER)a
Camplyobacter jejuni isolation requires the fecal specimen to be:
a. Inoculated onto selective plating media and incubated in reduced oxygen with added CO2 at
42 degrees C
b. stored in tryptic soy broth before plating to ensure growth of organism
c. inoculated onto selective plating media and incubated at both 35 degrees C and at room
temperature
, d. incubated at 35 degrees C for 2 hours in Cary-Blair media before inoculating onto selective
plating media - (ANSWER)a
Which of the following specimen requests is acceptable?
a. feces submitted for anaerobe culture
b. Foley catheter tip submitted for aerobic culture
c. rectal swab submitted for direct smear for gonococci
d. urine for culture of acid-fast bacilli - (ANSWER)d
A CSF specimen containing only 2 drops of CSF was collected by lumbar puncture from a
febrile 25-year old male and was submitted for a stat gram stain and culture. The direct specimen
Gram stain was reported as many neutrophils and no microorganism seen. The remain drop of
CSF should be inoculated to:
a. blood agar
b. CNA agar
c. chocolate agar
d. Thayer-Martin agar - (ANSWER)c
A diabetic foot swab from an 82 year old woman with recurrent infections is submitted for
culture. The gram stain reveals:
Many neutrophils, no squamous epithelial cells
Many Gram-negative bacilli
Many Gram-positive cocci in chains
The physician requests that all pathogens be worked up. In addition to the sheep blood, chocolate
and MacConkey agar plates routinely used for wound cultures, the technologist might also
process an:
a. anaerobic blood agar plate
b. BCYE agar plate
c. CNA agar plate
d. XLD agar plate - (ANSWER)c
