Povidone iodine (Betadine\textsuperscript{\textregistered})

Question 1

Which of the following best explains why alcohol-based hand sanitizers are ineffective against Clostridium difficile infections?

Accepted Answer

Alcohols do not destroy bacterial endospores, which Clostridium difficile produces.

Question 2

Which chemical disinfectant is considered sporicidal and is commonly used to sterilize medical equipment that cannot be autoclaved?

Accepted Answer

Glutaraldehyde

Question 3

Why are gram-negative bacteria generally more resistant to chemical biocides than gram-positive bacteria?

Accepted Answer

Their outer membrane contains lipopolysaccharides that restrict entry of biocides.

Question 4

Which of the following statements about phenolics is TRUE?

Accepted Answer

Phenolics disrupt plasma membranes and remain active in the presence of organic matter.

Question 5

A hospital needs to sterilize heat-sensitive electronic equipment. Which method is most appropriate?

Accepted Answer

Exposure to ethylene oxide gas in a sealed chamber

Question 6

Which of the following is a major advantage of glutaraldehyde over other chemical disinfectants?

Accepted Answer

It is effective against bacterial endospores (sporicidal).

Question 7

Which of the following is an example of a halogen used as an antiseptic?

Accepted Answer

Povidone iodine (Betadine	extsuperscript{	extregistered})

Question 8

A food processing plant wants to prevent the germination of Clostridium botulinum endospores in canned meats. Which preservative should be used?

Accepted Answer

Nitrites

Question 9

Which of the following best describes the mechanism of action of heavy metals such as silver and mercury in microbial control?

Accepted Answer

They denature proteins through oligodynamic action.

Question 10

Which surface-active agent is commonly used in the dairy industry due to its effectiveness and safety?

Accepted Answer

Benzalkonium chloride (a quaternary ammonium compound)

Question 11

Which of the following statements about peroxygens is correct?

Accepted Answer

Peracetic acid is an effective liquid sterilant for medical equipment.

Question 12

Which of the following is a gaseous chemosterilant that sterilizes by alkylation?

Accepted Answer

Ethylene oxide

Question 13

Why are nonenveloped viruses generally more resistant to chemical biocides than enveloped viruses?

Accepted Answer

They have a thicker protein coat that resists chemical penetration.

Question 14

Which essential oil component is primarily responsible for the antimicrobial activity of oregano?

Accepted Answer

Carvacrol

Question 15

A mortician is preparing a body for embalming. Which chemical is most likely to be used for this purpose?

Accepted Answer

Formalin

Question 16

Which of the following is NOT a correct use of antibiotics in microbial control?

Accepted Answer

Antibiotics are used to treat viral infections in food.

Question 17

Which of the following statements about aldehydes is TRUE?

Accepted Answer

Aldehydes inactivate proteins by cross-linking with functional groups.

Question 18

Which of the following is a correct statement about the use of chlorine in microbial control?

Accepted Answer

Chlorine acts as an oxidizing agent, shutting down cellular enzyme systems.

Question 19

Which of the following is a reason why prions are difficult to destroy during sterilization procedures?

Accepted Answer

Prions are resistant to standard chemical and physical sterilization methods.

Question 20

Which of the following best describes the use of supercritical fluids in microbial control?

Accepted Answer

They are used to sterilize heat-sensitive medical implants by combining gaseous and liquid properties.

Chemical Methods of Microbial Control: Study Notes for Microbiology Students

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