Microbiology, 2021

13 • Review Questions 555
12. Bleach is an example of which group of
chemicals used for disinfection?
A. heavy metals
B. halogens
C. quats
D. bisbiguanides
13. Which chemical disinfectant works by
methylating enzymes and nucleic acids and is
known for being toxic and carcinogenic?
A. sorbic acid
B. triclosan
C. formaldehyde
D. hexaclorophene
14. Which type of test is used to determine whether
disinfectant solutions actively used in a clinical
setting are being used correctly?
A. disk-diffusion assay
B. phenol coefficient test
C. in-use test
D. use-dilution test
15. The effectiveness of chemical disinfectants has
historically been compared to that of which of
the following?
A. phenol
B. ethyl alcohol
C. bleach
D. formaldehyde
16. Which of the following refers to a germicide that
can kill vegetative cells and certain enveloped
viruses but not endospores?
A. high-level germicide
B. intermediate-level germicide
C. low-level germicide
D. sterilant
True/False
17. Sanitization leaves an object free of microbes.
18. Ionizing radiation can penetrate surfaces, but
nonionizing radiation cannot.
19. Moist-heat sterilization protocols require the
use of higher temperatures for longer periods of
time than do dry-heat sterilization protocols do.
Fill in the Blank
22. A medical item that comes into contact with
intact skin and does not penetrate sterile
tissues or come into contact with mucous
membranes is called a(n) ________ item.
23. The goal of ________ ________ protocols is to
rid canned produce of Clostridium botulinum
endospores.
24. In an autoclave, the application of pressure to
________ is increased to allow the steam to
achieve temperatures above the boiling point of
water.
Short Answer
29. What are some characteristics of microbes and
infectious agents that would require handling in
a BSL-3 laboratory?
20. Soaps are classified as disinfectants.
21. Mercury-based compounds have fallen out of
favor for use as preservatives and antiseptics.
25. Doorknobs and other surfaces in clinical
settings are often coated with ________,
________, or ________ to prevent the
transmission of microbes.
26. If a chemical disinfectant is more effective than
phenol, then its phenol coefficient would be
________ than 1.0.
27. If used for extended periods of time, ________
germicides may lead to sterility.
28. In the disk-diffusion assay, a large zone of
inhibition around a disk to which a chemical
disinfectant has been applied indicates
________ of the test microbe to the chemical
disinfectant.
30. What is the purpose of degerming? Does it
completely eliminate microbes?
31. What are some factors that alter the
effectiveness of a disinfectant?