Question 1

Rectal swab is:&#10;A) acceptable.&#10;B) not acceptable.

Accepted Answer

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:&#10;A) take care not to tip the container.&#10;B) hold the collected specimen in the refrigerator until processing.&#10;C) hold the collected specimen in the incubator until processing.&#10;D) avoid opening the container in an aerobic atmosphere.

Accepted Answer

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?&#10;A) Bacteroides spp.&#10;B) Clostridia spp.&#10;C) Actinomyces spp.&#10;D) Veillonella spp.

Accepted Answer

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

Accepted Answer

An alternative to the commercial anaerobic devices available, the evacuation-replacement method can be used.Air is removed from a sealed jar by drawing a vacuum of 25 inches (62.5 cm)of mercury.This process is repeated two times, filling the jar with an oxygen-free gas, such as nitrogen, between evacuations.The final fill of the jar is made with a gas mixture containing 80% to 90% nitrogen, 5% to 10% hydrogen, and 5% to 10% CO₂.

Question 5

Tissue biopsy taken from a puncture wound is:&#10;A) acceptable.&#10;B) not acceptable.

Accepted Answer

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.In general, material for anaerobic culture is best obtained by tissue biopsy or by aspiration using a needle and syringe.

Question 6

Aspiration of peritoneal fluid using a needle and syringe is:&#10;A) acceptable.&#10;B) not acceptable.

Accepted Answer

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.In general, material for anaerobic culture is best obtained by tissue biopsy or by aspiration using a needle and syringe.

Question 7

Actinomyces spp., Bifidobacterium spp., and Clostridium spp.can be described as:&#10;A) aerotolerant organisms that can grow in the presence of either reduced or atmospheric oxygen but grow best under microaerobic conditions.&#10;B) strictly anaerobic organisms that cannot grow in the presence of either reduced or atmospheric oxygen but grow only under anaerobic conditions.&#10;C) microaerophilic organisms that can grow in the presence of either reduced or atmospheric oxygen but grow best under anaerobic conditions.&#10;D) facultatively anaerobic organisms that grow in the presence or absence of atmospheric oxygen.

Accepted Answer

Chapter 41 includes some microaerophilic organisms, such as Actinomyces spp., Bifidobacterium spp., and Clostridium spp.that can grow in the presence of either reduced or atmospheric oxygen but grow best under anaerobic conditions.

Question 8

The indicator used to determine whether anaerobic conditions are achieved in an anaerobic jar is:&#10;A) phenol red.&#10;B) bromothymol blue.&#10;C) methylene blue.&#10;D) methyl red.

Accepted Answer

Methylene blue is used as an indicator to determine whether anaerobic conditions have been met.The strip is blue in the presence of oxygen and turns white once anaerobic conditions are achieved.

Question 9

Prereduced, anaerobically sterilized (PRAS)media:&#10;A) are produced, packaged, shipped, and stored under anaerobic conditions.&#10;B) have a short shelf life of only 2 weeks.&#10;C) enable the culture to be incubated in the regular incubator under aerobic conditions.&#10;D) contain peroxides that enhance the growth of certain anaerobes.

Accepted Answer

Optimally, media for anaerobic culture should be pretreated to eliminate oxygen.Reduction of media in an anaerobic environment eliminates dissolved oxygen but has no effect on the peroxides that may accumulate over time and inhibit growth.PRAS media are produced, packaged, shipped, and stored under anaerobic conditions.

Question 10

Nasopharyngeal swab is:&#10;A) acceptable.&#10;B) not acceptable.

Accepted Answer

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.

Question 11

Cervical swab is:&#10;A) acceptable.&#10;B) not acceptable.

Accepted Answer

The answer of Cervical swab is:&#10;A) acceptable.&#10;B) not acceptable....

Question 12

Expectorated sputum is:&#10;A) acceptable.&#10;B) not acceptable.

Accepted Answer

The answer of Expectorated sputum is:&#10;A) acceptable.&#10;B) not acceptable....

Question 13

Urine via catheter is:&#10;A) acceptable.&#10;B) not acceptable.

Accepted Answer

The answer of Urine via catheter is:&#10;A) acceptable.&#10;B) not acceptable....

Question 14

Urine via percutaneous aspiration is:&#10;A) acceptable.&#10;B) not acceptable.

Accepted Answer

The answer of Urine via percutaneous aspiration is:&#10;A) acceptable.&#10;B) not...

Question 15

To isolate anaerobic gram-positive organisms, which of the following media should be used?&#10;A) Anaerobic blood agar&#10;B) Cycloserine cefoxitin fructose agar (CCFA)&#10;C) Laked kanamycin-vancomycin (LKV) blood agar&#10;D) Anaerobic phenylethyl alcohol agar (PEA)

Accepted Answer

The answer of To isolate anaerobic gram-positive organisms, which of...

Question 16

An acceptable specimen for anaerobic culture is:&#10;A) nasopharyngeal swab.&#10;B) tissue obtained at biopsy.&#10;C) small bowel contents.&#10;D) catheterized urine.

Accepted Answer

The answer of An acceptable specimen for anaerobic culture is:&#10;A)...

Question 17

Bronchial washing collected with a double lumen-plugged catheter is:&#10;A) acceptable.&#10;B) not acceptable.

Accepted Answer

The answer of Bronchial washing collected with a double lumen-plugged...

Question 18

Percutaneous lung aspirate is:&#10;A) acceptable.&#10;B) not acceptable.

Accepted Answer

The answer of Percutaneous lung aspirate is:&#10;A) acceptable.&#10;B) not acceptable....

Question 19

Feces in a sterile specimen cup is:&#10;A) acceptable.&#10;B) not acceptable.

Accepted Answer

The answer of Feces in a sterile specimen cup is:&#10;A)...

Question 20

MATCHING&#10;Match the media with its primary purpose.a.Isolates of Prevotella and Bacteroides spp.&#10;b.Inhibits gram-negative rods&#10;c.Is nonselective; supports the growth of facultative anaerobes and aerobes&#10;d.Determines lecithinase and lipase production of Clostridia and Fusobacteria&#10;e.Is selective for Clostridium difficile&#10;Egg-yolk agar

Accepted Answer