Chapter 9
A nurse preparing a section of skin for an injection is an example of __________.
degerming
A broth containing 1 million bacterial cells is treated with an antimicrobial agent that kills 90% of the cells in 1 minute. What is the minimum amount of time it will take before all the cells in the broth are dead?
7 minutes
An antimicrobial chemical used on the skin is usually called a(n) __________.
antiseptic
Which of the following statements is TRUE of disinfectants?
You notice a sign in a public restroom that states "Sanitized for your safety." This means
methods of disinfection that meet minimum standards of microbial removal have been used.
A chemical agent that dissolves lipids can damage
cells and enveloped viruses
Which of the following is most susceptible to antimicrobial agents?
vegetative bacteria
An instrument coming into contact with the skin of an immunocompromised patient should be treated with which of the following?
high-level germicide
Desiccation, a time-honored method of preserving food, is effective because the
water content is too low to support metabolic function
Put the following microbes in order of their resistance to antimicrobial agents, from least to most resistant: a. prions b. enveloped viruses c. mycobacteria d. Gram-negative bacteria
b, d, c, a
An instrument that will come into contact with only the skin of a patient should be disinfected with a(n)
low-level germicide.
Which of the following is NOT a desirable characteristic of an ideal antimicrobial agent?
it only arrests growth of vegetative cells
Methods of microbial control called ________ arrest the growth of microbes.
microbistatic
Which of the following is the most difficult to inactivate?
bacterial endospores
Compared to moist heat methods, dry heat needs which of the following in order to sterilize effectively?
higher temperature and increased time
Which of the following techniques can be used to sterilize microbiological media?
autoclaving
Which of the following could be used to sterilize a heat-sensitive liquid such as urea broth?
filtration
Which of the following is bacteriostatic?
freezing below 0°C
Standard pasteurization methods are used to
reduce microbes that cause disease or spoilage
Boiling water for 10 minutes is effective in ridding it of
both growing bacteria and enveloped viruses
Which of the following is used to sterilize items that should not, or cannot, be exposed to heat or water?
ethylene oxide
Which of the following is used for microbial control in fresh fruits and vegetables?
gamma rays
The process of incineration is used for
sterilization
Iodophors and chloramines are similar in that they are both halogen-containing compounds that __________.
slowly release their active ingredients
Which of the following would be used to sterilize a mattress?
ethylene oxide
Which of the following is a low-level disinfectant?
quats
Silvadene, a topical treatment for burns, contains 1% silver. What category of chemical control agent is in Silvadene?
heavy metals
Seventy percent alcohol is effective against
enveloped viruses.
Which of the following antimicrobial agents is the most toxic to humans?
ethylene oxide