Deck 40: Overview and General Considerations

Question 1

Rectal swab is:

A) acceptable.
B) not acceptable.

Answer 1

B
Because indigenous anaerobes are often present in large numbers as normal flora on mucosal surfaces, even minimal contamination of a specimen can give misleading results.Specimens that are likely to be contaminated are unacceptable for anaerobic culture.A rectal swab would be highly contaminated with normal bowel flora.

Question 2

During specimen collection, an important thing to remember when handling a collection device with an oxygen-free atmosphere is to:

A) take care not to tip the container.
B) hold the collected specimen in the refrigerator until processing.
C) hold the collected specimen in the incubator until processing.
D) avoid opening the container in an aerobic atmosphere.

Answer 2

A
When tubes or other oxygen-free devices are used for the collection of specimens for anaerobic culture, care must be taken not to tip the container, which would cause the oxygen-free carbon dioxide (CO₂)or nitrogen to spill out and be displaced by ambient air, which contains oxygen.

Question 3

An anaerobic media, which contains ferric ammonium citrate and hemin, bile salts, and gentamicin, is used to isolate which group of organisms?

A) Bacteroides spp.
B) Clostridia spp.
C) Actinomyces spp.
D) Veillonella spp.

Answer 3

A
Bacteroides bile esculin (BBE)agar contains a trypticase soy agar base with ferric ammonium citrate and hemin; bile salts and gentamicin act as inhibitors.BBE is selective and differential for the Bacteroides fragilis group.

Question 4

The final fill of the anaerobe jar prepared by the evacuation-replacement method consists of:

A) 20% to 30% nitrogen, 5% to 10% hydrogen, and 70% to 80% CO2.
B) 80% to 90% oxygen, 5% to 10% hydrogen, and 5% to 10% CO2.
C) 80% to 90% nitrogen, 5% to 10% hydrogen, and 5% to 10% CO2.
D) 80% to 90% nitrogen, 5% to 10% oxygen, and 5% to 10% CO2.

Question 5

Tissue biopsy taken from a puncture wound is:

A) acceptable.
B) not acceptable.

Question 6

Aspiration of peritoneal fluid using a needle and syringe is:

A) acceptable.
B) not acceptable.

Question 7

Actinomyces spp., Bifidobacterium spp., and Clostridium spp.can be described as:

A) aerotolerant organisms that can grow in the presence of either reduced or atmospheric oxygen but grow best under microaerobic conditions.
B) strictly anaerobic organisms that cannot grow in the presence of either reduced or atmospheric oxygen but grow only under anaerobic conditions.
C) microaerophilic organisms that can grow in the presence of either reduced or atmospheric oxygen but grow best under anaerobic conditions.
D) facultatively anaerobic organisms that grow in the presence or absence of atmospheric oxygen.

Question 8

The indicator used to determine whether anaerobic conditions are achieved in an anaerobic jar is:

A) phenol red.
B) bromothymol blue.
C) methylene blue.
D) methyl red.

Question 9

Prereduced, anaerobically sterilized (PRAS)media:

A) are produced, packaged, shipped, and stored under anaerobic conditions.
B) have a short shelf life of only 2 weeks.
C) enable the culture to be incubated in the regular incubator under aerobic conditions.
D) contain peroxides that enhance the growth of certain anaerobes.

Question 10

Nasopharyngeal swab is:

A) acceptable.
B) not acceptable.

Question 11

Cervical swab is:

A) acceptable.
B) not acceptable.

Question 12

Expectorated sputum is:

A) acceptable.
B) not acceptable.

Question 13

Urine via catheter is:

A) acceptable.
B) not acceptable.

Question 14

Urine via percutaneous aspiration is:

A) acceptable.
B) not acceptable.

Question 15

To isolate anaerobic gram-positive organisms, which of the following media should be used?

A) Anaerobic blood agar
B) Cycloserine cefoxitin fructose agar (CCFA)
C) Laked kanamycin-vancomycin (LKV) blood agar
D) Anaerobic phenylethyl alcohol agar (PEA)

Question 16

An acceptable specimen for anaerobic culture is:

A) nasopharyngeal swab.
B) tissue obtained at biopsy.
C) small bowel contents.
D) catheterized urine.

Question 17

Bronchial washing collected with a double lumen-plugged catheter is:

A) acceptable.
B) not acceptable.

Question 18

Percutaneous lung aspirate is:

A) acceptable.
B) not acceptable.

Question 19

Feces in a sterile specimen cup is:

A) acceptable.
B) not acceptable.

Question 20

MATCHING
Match the media with its primary purpose.a.Isolates of Prevotella and Bacteroides spp.
b.Inhibits gram-negative rods
c.Is nonselective; supports the growth of facultative anaerobes and aerobes
d.Determines lecithinase and lipase production of Clostridia and Fusobacteria
e.Is selective for Clostridium difficile
Egg-yolk agar

Question 21

MATCHING
Match the media with its primary purpose.a.Isolates of Prevotella and Bacteroides spp.
b.Inhibits gram-negative rods
c.Is nonselective; supports the growth of facultative anaerobes and aerobes
d.Determines lecithinase and lipase production of Clostridia and Fusobacteria
e.Is selective for Clostridium difficile
Thioglycollate broth

Question 22

MATCHING
Match the media with its primary purpose.a.Isolates of Prevotella and Bacteroides spp.
b.Inhibits gram-negative rods
c.Is nonselective; supports the growth of facultative anaerobes and aerobes
d.Determines lecithinase and lipase production of Clostridia and Fusobacteria
e.Is selective for Clostridium difficile
LKV blood agar

Question 23

MATCHING
Match the media with its primary purpose.a.Isolates of Prevotella and Bacteroides spp.
b.Inhibits gram-negative rods
c.Is nonselective; supports the growth of facultative anaerobes and aerobes
d.Determines lecithinase and lipase production of Clostridia and Fusobacteria
e.Is selective for Clostridium difficile
PEA agar

Question 24

MATCHING
Match the media with its primary purpose.a.Isolates of Prevotella and Bacteroides spp.
b.Inhibits gram-negative rods
c.Is nonselective; supports the growth of facultative anaerobes and aerobes
d.Determines lecithinase and lipase production of Clostridia and Fusobacteria
e.Is selective for Clostridium difficile
CCFA