Q: A disinfectant is tested at two temperatures: $20^\\circ C$ and $45^\\circ C$. According to the provided graph, which statement is correct?

Microbial death rate is higher at $45^\\circ C$ than at $20^\\circ C$.

Question 1

Which of the following microbial forms is most resistant to antimicrobial agents?

Accepted Answer

Prions

Question 2

A hospital is planning to sterilize surgical instruments that may be contaminated with Mycobacterium tuberculosis. Which factor should be considered when selecting an antimicrobial method?

Accepted Answer

The high lipid content in the cell wall of Mycobacterium tuberculosis

Question 3

Why are nonenveloped viruses generally more resistant to antimicrobial agents than enveloped viruses?

Accepted Answer

Nonenveloped viruses have a protein coat that is less susceptible to chemical disruption than the lipid envelope of enveloped viruses.

Question 4

Which environmental condition can decrease the efficacy of a chemical disinfectant when cleaning a surface?

Accepted Answer

Presence of organic matter such as blood or feces

Question 5

Acanthamoeba keratitis is an emerging disease often associated with which real-world scenario?

Accepted Answer

Swimming in lakes and wearing contact lenses

Question 6

Which biosafety level (BSL) is required for handling Ebola virus in a laboratory?

Accepted Answer

BSL-4

Question 7

A laboratory technician is working with Escherichia coli. What is the minimum biosafety level required?

Accepted Answer

BSL-1

Question 8

Which of the following statements best explains why bacterial endospores are highly resistant to heat and chemicals?

Accepted Answer

Endospores have a thick protein coat and can remain dormant for long periods.

Question 9

A disinfectant is tested at two temperatures: $20^\circ C$ and $45^\circ C$. According to the provided graph, which statement is correct?

Accepted Answer

Microbial death rate is higher at $45^\circ C$ than at $20^\circ C$.

Question 10

Which of the following is a critical factor when choosing an antimicrobial method for treating a patient with a biofilm-associated infection?

Accepted Answer

The ability of the agent to penetrate the biofilm matrix

Question 11

Which group of microorganisms is most susceptible to antimicrobial agents?

Accepted Answer

Enveloped viruses

Question 12

A medical device contaminated with cysts of Cryptosporidium requires disinfection. Which property of these cysts makes them difficult to eliminate?

Accepted Answer

A protective outer shell that resists chemical disinfectants

Question 13

Which of the following best describes the function of HEPA filters in a BSL-3 laboratory?

Accepted Answer

They remove airborne pathogens before air leaves the laboratory.

Question 14

A scientist is working with Mycobacterium tuberculosis. Which biosafety level is required and why?

Accepted Answer

BSL-3, because it is an airborne pathogen with high risk to laboratory personnel.

Question 15

Which of the following is NOT a factor affecting the efficacy of antimicrobial methods?

Accepted Answer

Color of the microorganism

Question 16

A patient develops Acanthamoeba keratitis after swimming in a lake. Which property of Acanthamoeba makes treatment challenging?

Accepted Answer

Ability to form cysts that resist chemical disinfectants

Question 17

Which of the following equations best represents the relationship between microbial death rate and temperature, as shown in the provided graph?

Accepted Answer

$N_t = N_0 e^{-kt}$, where $k$ increases with temperature

Question 18

Which biosafety level requires personnel to wear 'space suits' and work in completely isolated facilities?

Accepted Answer

BSL-4

Question 19

Why might the use of medical instruments on patients with prion diseases require special sterilization procedures?

Accepted Answer

Prions are highly resistant to standard sterilization methods, including heat and chemicals.

Question 20

A hospital is disinfecting a room after treating a patient with vegetative bacteria. Which of the following is most likely to be effective?

Accepted Answer

Low-level disinfectant

Microbial Control Methods: Efficacy Factors, Resistance, and Biosafety

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