What bacteria have porins, are resistant to bisphenols, and survive and may grow in quats?

Which of the following does not kill endospores?

a. autoclaving

b. incineration

c. hot-air sterilization

d. pasteurization

e. All of the above kill endospores.

Which of the following is most likely to be bactericidal?

a. membrane filtration

b. ionizing radiation

c. lyophilization (freeze-drying)

d. deep-freezing

e. all of the above

Which of the following is most effective for sterilizing mattresses and plastic Petri dishes?

a. chlorine

b. ethylene oxide

c. glutaraldehyde

d. autoclaving

e. nonionizing radiation

Which of these disinfectants does not act by disrupting the plasma membrane?

a. phenolics

b. phenol

c. quats

d. halogens

e. biguanides

Which of the following cannot be used to sterilize a heat-labile solution stored in a plastic container?

a. gamma radiation

b. ethylene oxide

c. supercritical fluids

d. autoclaving

e. short-wavelength radiation

Which of the following is used to control microbial growth in foods?

a. organic acids

b. alcohols

c. aldehydes

d. heavy metals

e. all of the above

How do autoclaving, hot air, and ultra-high-temperature pasteurization illustrate the concept of equivalent treatments?

Use the following information to answer questions 6 and 7. The data were obtained from a use-

dilution test comparing four disinfectants against Salmonella Choleraesuis.

G = growth, NG = no growth <IMAGE>

Which disinfectant is the most effective?

How do salts and sugars preserve foods? Why are these considered physical rather than chemical methods of microbial control? Name one food that is preserved with sugar and one preserved with salt. How do you account for the occasional growth of Penicillium mold in jelly, which is 50% sucrose?

Use the following information to answer questions 6 and 7. The data were obtained from a use-

dilution test comparing four disinfectants against Salmonella Choleraesuis.

G = growth, NG = no growth <IMAGE>

Which disinfectant(s) is (are) bactericidal?

a. A,B,C, and D

b. A,C, and D

c. A only

d. B only

e. none of the above

Which of the following is not a characteristic of quaternary ammonium compounds?

a. bactericidal against gram-positive bacteria

b. sporicidal

c. amebicidal

d. fungicidal

e. kills enveloped viruses

A large hospital washes burn patients in a stainless steel tub. After each patient, the tub is cleaned with a quat. It was noticed that 14 of 20 burn patients acquired Pseudomonas infections after being bathed. Provide an explanation for this high rate of infection.

You and your classmates are trying to determine how a disinfectant might kill cells. You observe that when you spill the disinfectant in a tube of reduced litmus milk, the litmus turns blue again. You suggest to your classmates that

a. the disinfectant might inhibit cell wall synthesis.

b. the disinfectant might oxidize molecules.

c. the disinfectant might inhibit protein synthesis.

d. the disinfectant might denature proteins.

e. the disinfectant might damage DNA.

DRAW IT Show where the following antibiotics work: ciprofloxacin, tetracycline, streptomycin, vancomycin, polymyxin B, sulfanilamide, rifampin, erythromycin.

<IMAGE>

NAME IT This microorganism is not susceptible to antibiotics or neuromuscular blocks, but is susceptible to protease inhibitors.

Which of the following pairs is mismatched?

a. antihelminthic—inhibition of oxidative phosphorylation

b. antihelminthic—inhibition of cell wall synthesis

c. antifungal—injury to plasma membrane

d. antifungal—inhibition of mitosis

e. antiviral—inhibition of DNA synthesis

Chloramphenicol binds to the 50S portion of a ribosome, which will interfere with

a. transcription in prokaryotic cells.

b. transcription in eukaryotic cells.

c. translation in prokaryotic cells.

d. translation in eukaryotic cells.

e. DNA synthesis.

List and explain five criteria used to identify an effective antimicrobial agent.

All of the following are modes of action of antiviral drugs except

a. inhibition of protein synthesis at 70S ribosomes.

b. inhibition of DNA synthesis.

c. inhibition of RNA synthesis.

d. inhibition of uncoating.

e. All of the above are modes of action of antiviral drugs.

What similar problems are encountered with antiviral, antifungal, antiprotozoan, and antihelminthic drugs?

Which of the following modes of action would not be fungicidal?

a. inhibition of peptidoglycan synthesis

b. inhibition of mitosis

c. injury to the plasma membrane

d. inhibition of nucleic acid synthesis

e. All of the above are fungicidal modes of action.

Define drug resistance. How is it produced? What measures can be taken to minimize drug resistance?

An antimicrobial agent should meet all of the following criteria except

a. selective toxicity.

b. the production of hypersensitivities.

c. a narrow spectrum of activity.

d. no production of drug resistance.

e. All of the above are necessary criteria for an antimicrobial.

List the advantages of using two chemotherapeutic agents simultaneously to treat a disease. What problem can occur when two drugs are used?

The most selective antimicrobial activity would be exhibited by a drug that

a. inhibits cell wall synthesis.

b. inhibits protein synthesis.

c. injures the plasma membrane.

d. inhibits nucleic acid synthesis.

e. all of the above

Why does a cell die from the following antimicrobial actions?

a. Colistimethate binds to phospholipids.

b. Kanamycin binds to 70S ribosomes.

Antibiotics that inhibit translation have side effects

a. because all cells have proteins.

b. only in the few cells that make proteins.

c. because eukaryotic cells have 80S ribosomes.

d. at the 70S ribosomes in eukaryotic cells.

e. None of the above is correct.

How does each of the following inhibit translation?

a. chloramphenicol

b. erythromycin

c. tetracycline

d. streptomycin

e. oxazolidinone

f. streptogramin

Which of the following will not affect eukaryotic cells?

a. inhibition of the mitotic spindle

b. binding with sterols

c. binding to 80S ribosomes

d. binding to DNA

e. All of the above will affect them.