BOC Microbiology Exam Questions With
Correct Answers A+
The aseptic collection of blood cultures requires that the skin be cleansed with: - Answer✔70%
alcohol and 2% iodine or an iodophor.
When cleansing the skin with alcohol and then iodine for the collection of a blood culture, the
iodine (or iodophor) should remain intact on the skin for at least: - Answer✔60 seconds
What is the purpose of adding 0.025% to 0.050% sodium polyanetholsulfonate (SPS) to nutrient
broth media for the collection of blood cultures? - Answer✔It inhibits phagocytosis and
complement
A flexible calcium alginate nasopharyngeal swab is the collection device of choice for recovery
of which organism from the nasopharynx? - Answer✔Corynebacterium diphtheriae
Semisolid transport media such as Amies, Stuart, or Cary-Blair are suitable for the transport of
swabs for culture of most pathogens except: - Answer✔Neisseria gonorrhoeae
What is the best method of recovery of anaerobic bacteria from a deep abscess?
-Cotton Fiber swab of abscess area
-Skin snip of surface tissue
-Needle aspirate after surface decontamination
-Swab of the scalpel used for debridement - Answer✔Needle aspirate after surface
decontamination
What is the primary and differential media of choice for recovery of most fecal pathogens? -
Answer✔Hekotoen, MacConkey, Campy, colistin-nalidixic acid (CNA) agars
What is the media of choice for recovery of Vibrio cholerae from a stool specimen? -
Answer✔Thiosulfate-citrate-bile-sucrose (TCBS) agar and alkaline peptone water (APW) broth
Colistin-nalidixic acid agar (CNA) is used primarily for the recovery of: -
Answer✔Staphylococcus aureus
In the United States, most blood agar plates are prepared with 5% or 10% red blood cells (RBCs)
obtained from: - Answer✔Sheep