11. Controlling Microbial Growth

A broad-spectrum drug is best described as

a. bactericidal against a wide range of species.

b. bacteriostatic against a wide range of species.

c. effective against a wide range of species.

d. empiric therapy.

e. selectively toxic.

A patient who is not a healthcare worker is diagnosed with C. difficile pseudomembranous colitis. What most likely led to this infection? (NCLEX/HESI/TEAS)

a. The patient was recently treated with a bacteriostatic drug.

b. The patient was recently treated with a broad-spectrum drug.

c. The patient was treated with a bactericidal drug.

d. The patient recently became immune compromised and therefore had an increased risk for infection.

e. The patient was recently exposed to someone with an active C. difficile infection.

Assume a bacterium makes beta-lactamase. Could you still use a glycopeptide drug to treat an infection caused by this bacterium? Explain your reasoning.

If a gene encoding a bacterial transpeptidase enzyme undergoes mutation, which of the following antimicrobials may no longer be effective against the mutated bacterium?

a. Macrolides

b. Polypeptide drugs

c. Tetracyclines

d. Penicillins

e. Quinolones

Which of the following disinfectants acts against cell membranes?

a. phenol

b. peracetic acid

c. silver nitrate

d. glutaraldehyde

Which antimicrobial chemical has been used to sterilize spacecraft?

a. phenol

b. alcohol

c. heavy metal

d. ethylene oxide

Which class of surfactant is most soluble in water?

a. quaternary ammonium compounds

b. alcohols

c. soaps

d. peracetic acids

Which of the following substances or processes kills microorganisms on laboratory surfaces?

a. antiseptics

b. disinfectants

c. degermers

d. pasteurization

The microbial death rate is used to measure the effectiveness of            .

a. a detergent

b. an antiseptic

c. sanitization techniques

d. all of the above

Which of the following statements is true concerning the selection of an antimicrobial agent?

a. An ideal antimicrobial agent is stable during storage.

b. An ideal antimicrobial agent is fast acting.

c. Ideal microbial agents do not exist.

d. All of the above are correct.

Describe three types of microbes that are extremely resistant to antimicrobial treatment, and explain why they are resistant.

Compare and contrast four tests that have been developed to measure the effectiveness of disinfectants.

Why is it necessary to use strong disinfectants in areas exposed to tuberculosis patients?

Cross resistance is __________ .

a. the deactivation of an antimicrobial agent by a bacterial enzyme

b. alteration of the resistant cells so that an antimicrobial agent cannot attach

c. the mutation of genes that affect the cytoplasmic membrane channels so that antimicrobial agents cannot cross into the cell’s interior

d. resistance to one antimicrobial agent because of its similarity to another antimicrobial agent

Multiple-drug-resistant microbes _____________________  .

a. are resistant to all antimicrobial agents

b. respond to new antimicrobials by developing resistance

c. frequently develop in hospitals

d. all of the above