Question 1

Which of the following best describes sterilization?

Accepted Answer

The destruction or removal of all forms of microbial life, including spores.

Question 2

A surgical instrument that will enter sterile tissue must undergo which of the following processes before use?

Accepted Answer

Sterilization

Question 3

Which of the following statements about autoclaves is CORRECT?

Accepted Answer

Steam at 121°C for 15 minutes at 15 psi is used to achieve sterilization.

Question 4

Which physical method is most appropriate for sterilizing heat-sensitive liquids such as vaccines?

Accepted Answer

Filtration

Question 5

Which of the following is a limitation of using ultraviolet (UV) radiation for sterilization?

Accepted Answer

It has poor penetration and is not effective for sterilizing surfaces with shadows or crevices.

Question 6

Which chemical agent is most appropriate for disinfecting a computer keyboard in a patient room?

Accepted Answer

Quaternary ammonium compound

Question 7

A hospital uses a spore strip to monitor the effectiveness of its autoclave. What does a positive result (growth of spores) indicate?

Accepted Answer

The autoclave failed to sterilize the load.

Question 8

Which of the following is a property of an ideal chemical disinfectant?

Accepted Answer

Works against a broad spectrum of microbes and is fast acting

Question 9

Which of the following best describes the action of alcohols as disinfectants?

Accepted Answer

They denature proteins and disrupt membranes but evaporate quickly.

Question 10

A laboratory spill of a bacterial culture containing heat-sensitive components occurs. What is the most appropriate method for decontamination?

Accepted Answer

Wiping with a quaternary ammonium compound

Question 11

Which of the following is the main reason why boiling is not considered a reliable method for sterilization?

Accepted Answer

It does not destroy bacterial endospores.

Question 12

Which of the following equations best represents the relationship between microbial death rate and time under constant conditions?

Accepted Answer

$$N_t = N_0$ e$$^{-kt}$$

Question 13

Which of the following is a disadvantage of using ethylene oxide (ETO) for sterilization?

Accepted Answer

It is toxic and requires aeration of products before use.

Question 14

Which of the following best explains why Gram-negative bacteria are often more resistant to disinfectants than Gram-positive bacteria?

Accepted Answer

Their outer membrane acts as a barrier to many chemicals.

Question 15

A hospital is evaluating a new disinfectant using the disk diffusion method. What does a larger zone of inhibition indicate?

Accepted Answer

The disinfectant is more effective at inhibiting microbial growth.

Question 16

Which of the following is the most appropriate method for decontaminating soiled linens from a highly infectious ICU patient?

Accepted Answer

Bagging at point of use and washing with hot water at 160°F for 25 minutes

Question 17

Which of the following is a key difference between disinfection and antisepsis?

Accepted Answer

Antisepsis is used on living tissues, while disinfection is used on inanimate objects.

Question 18

Which of the following best describes the action of halogens such as chlorine and iodine?

Accepted Answer

They are strong oxidizing agents that damage cellular components.

Question 19

Which of the following is the best method for sterilizing glass pipettes to be used in the laboratory?

Accepted Answer

Hot air oven at 160°C for 2 hours

Question 20

A heat-sensitive endoscope must be sterilized before use. Which method is most appropriate?

Accepted Answer

Ethylene oxide gas sterilization

Control of Microbial Growth: Methods and Applications in Healthcare and Laboratory Settings

Study Guide - Practice Questions