8.1 Specimen Collection, Media and Methods Flashcards
The aseptic collection of blood cultures requires that the skin be cleansed with:
A. 2% iodin and then 70% alcohol solution
B. 70% alcohol and then 2% iodine or an iodophor
C. 70% alcohol and then 95% alcohol
D. 95% alcohol only
B
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:
A. 10 sec
B. 30 sec
C. 60 sec
D. 5 min
C. 60secs
What is the purpose of adding 0.025%-0.050% sodium polyanetholsulfanate (SPS) to nutrient broth media for the collection of blood cultures?
A. It inhibits phagocytosis and complement
B. It promotes formation of a blood clot
C. It enhances growth of anaerobes
D. It functions as a preservative
A. It inhibits phagocytosis and complement
A flexible calcium alginate nasopharyngeal swab in the collection device of choice for recovery of which organism from the nasopharynx?
A. Staphylococcus aureus
B. Streptococcus pneumoniae
C. Corynebacterium diphtheriae
D. Bacteroides fragilis
C. Corynebacterium diphtheriae
Semisolid transport media such as Amies, Stuart, or Cary-Blair are suitable for the transport of swabs for culture of most pathogen except:
A. Neisseria gonorrhoeae
B. Enterobacteriaceae
C. Camplyobacter fetus
D. Streptococcus pneumoniae
A. Neisseria gonorrhoeae
Select the method of choice for recovery of anaerobic bacteria from a deep abscess.
A. Cotton fiver swab or the abscess area
B. Skin snip of the surface tissue
C. Needle aspirate after surface decontamination
D. Swab of the scalpel used for debridement
C. Needle aspirate after surface decontamination
Select the primary and differential media of choice for recovery of most fecal pathogens.
A. MacConkey, blood, birdseed, and Campylobacter (Campy) agars
B. Hektoen, MacConkey, Campy, colistin-nalidixic acid (CNA) agars
C. CNA and Christensen urea agars and thioglycollate media
D. Blood, Campy, Mueller-Hinton agars, and thioglycollate media
B. Hektoen, MacConkey, Campy, colistin-nalidixic acid (CNA) agars
Select the media of choice for recovery of Vibrio cholerae form a stool specimen.
A. MacConkey agar and thioglycollate media
B. Thiosulfate-citrate-bile sucrose (TCBS_ agar and alkaline peptone water (APW broth)
C. Blood agar and selenite-F (SEL) broth
D. CNA agar
B. Thiosulfate-citrate-bile sucrose (TCBS_ agar and alkaline peptone water (APW broth)
Colistin-nalidixic acid agar (CNA) is used primarily for the recovery of:
A. Neisseria species
B. Enterobacteriaceae
C. Pseudomonas aeruginosa
D. Staphylococcus
D. Staphylococcus
In the United States, most blood agar plates are prepared with 5% or 10% red blood cells (RBCs) obtained from:
A. Sheep
B. Horses
C. Humans
D. Dogs
A. Sheep
All of the following are appropriate when attempting to isolate N. gonorrheae from a genital specimen except:
A. Transport the genital swab in charcoal transport medium
B. Plate the specimen on modified Thayer-Marin (MTM) medium
C. Plate the specimen on New York City or Martin-Lewis agar
D. Culture specimens in ambient oxygen at 37C
D. Culture specimens in ambient oxygen at 37C
Chocolate agar and modified Thayer-Martin agar are used for the recovery of:
A. Haemophilus spp. and Neisseria spp., respectively
B. Haemophilus spp. and N. gonorrhoeae, respectively
C. Neisseria spp. and Streptococcus spp., respectively
D. Streptococcus spp. and Staphylococcus spp., respectively
B. Haemophilus spp. and N. gonorrhoeae, respectively
Cycloserine-cefoxitin-fructose agar (CCFA) is used for the recovery of:
A. Yersinia enterocolitica
B. Yersinia intermedia
C. Clostridium perfringens
D. Clostridium difficile
D. Clostridium difficile
Deoxycholate agar (DCA) is useful for the isolation of:
A. Enterobacteriaceae
B. Enterococcus spp.
C. Staphylococcus spp.
D. Neisseria spp.
A. Enterobacteriaceae
Xylose lysine deoxycholate (XLD) agar is a highly selective medium used for the recovery of which bacteria?
A. Staphylococcus spp. from normal flora
B. Yersinia spp. that do not grow on Hektoen agar
C. Enterobacteriaceae from gastrointestinal specimens
D. Streptococcus spp. from stool culture
C. Enterobacteriaceae from gastrointestinal specimens