1. Lister developed his ideas on prevention of infection during medical procedures after studying the work of
A. Koch.
B. Pasteur.
C. Jenner.
D. Fleming.

B. Pasteur.

2. One of the first chemicals used by Lister to prevent surgical infections was
A. alcohol.
B. iodine.
C. carbolic acid.
D. mercury.

C. carbolic acid.

3. The process of killing or removing all of the microorganisms in or on a material is termed
A. sterilization.
B. disinfection.
C. sanitation.
D. antisepsis.

A. sterilization.

4. A sterile item is free of
A. microbes.
B. endospores.
C. viruses.
D. prions.
E. microbes, endospores, AND viruses.

E. microbes, endospores, AND viruses.

5. A suffix used to describe a killing action would be
A. -static.
B. -cidal.
C. -cillin.
D. -tion.

B. -cidal.

6. Pasteurization
A. is the use of heat to sterilize food products.
B. is the use of heat to reduce numbers of pathogenic/spoilage bacteria in a food item to a safe level.
C. is a process that uses intense cold to kill microorganisms on foods.

D. is a process that uses short bursts of radiation to kill microorganisms on foods.

B. is the use of heat to reduce numbers of pathogenic/spoilage bacteria in a food item to a safe level.

7. Plain soap is very effective in controlling spread of microorganisms because it is
A. bacteriostatic.
B. very effective at the mechanical removal of microorganisms.
C. virucidal.
D. bactericidal.

B. very effective at the mechanical removal of microorganisms.

8. Nosocomial infections
A. are acquired at various social events.
B. are acquired while in the hospital.
C. occur because of a susceptible population and presence of disease-causing organisms.

D. are acquired at sporting events.
E. are acquired while in the hospital AND occur because of a susceptible population and presence of disease-causing organisms.

E. are acquired while in the hospital AND occur because of a susceptible population and presence of disease-causing organisms.

To reduce or eliminate disease-/spoilage-causing organisms, food is often subjected to

A. heat.
B. chemical additives.
C. radiation.
D. cold.
E. All of the choices are correct.

E. All of the choices are correct.

Which of the following organisms are resistant to destruction by typical disinfection methods?

A. Endospores of Bacillus and Clostridium

B. Pseudomonas
C. Non-enveloped viruses

D. Mycobacterium spp.
E. All of the choices are correct.

E. All of the choices are correct.

11. A common environmental organism that may even grow in certain chemical disinfectants is
A. Escherichia coli.
B. Streptococcus pneumoniae.
C. Pseudomonas aeruginosa.
D. enveloped virus.

C. Pseudomonas aeruginosa.

12. Upon treatment with heat or chemicals, bacteria will
A. all die immediately.
B. die at a constant proportion.

C. die at an exponential rate.
D. die at a geometric rate.

B. die at a constant proportion.

13. In a one D process, how many D values would it take to reduce a population of 10¹⁰ cells to one survivor?
A. 2
B. 4
C. 5
D. 10

D. 10

14. If a process kills 90% of the organisms per minute, how many minutes would it take to kill all organisms when starting with 100,000 organisms?
A. 1 minute
B. 2 minutes
C. 3 minutes
D. 6 minutes

D. 6 minutes

15. Microbial death rates may be affected by
A. pH.
B. temperature.
C. the presence of organics.
D. All of the choices are correct.

D. All of the choices are correct.

16. In order to speed up the sterilization process, which of the following would be useful?
A. Drying the material

B. Washing/mechanical removal of bacteria/organic matter

C. Addition of organics

D. Nothing

E. Washing/mechanical removal of bacteria/organic matter AND addition of organics

B. Washing/mechanical removal of bacteria/organic matter

17. Moist heat kills microorganisms by
A. irreversible denaturation of proteins.

B. destruction of carbohydrates in the cell wall.
C. denaturation of nucleic acids.
D. dissolving the capsule.

A. irreversible denaturation of proteins.

18. Boiling is not reliable for sterilization because
A. heat-sensitive instruments may be destroyed.

B. heat-resistant endospores are unaffected.

C. water boils at a higher temperature at lower altitudes.
D. viruses are more sensitive to heat than bacteria.

B. heat-resistant endospores are unaffected.

19. Typical conditions used for sterilization are
A. 100C for 10 minutes.
B. 121C at 15 psi for 15 minutes.
C. 80C for 15 minutes.
D. 72C for 15 seconds.

B. 121C at 15 psi for 15 minutes.

20. Which are essentially equivalent treatments?
A. Dry 200C heat for 1.5 hours; wet 121C heat for 15 minutes

B. Dry 160C heat for 1.0 hour; wet 200C heat for 30 minutes

C. Dry 121C heat for 1.5 hours; wet 200C heat for 15 minutes

D. Dry 100C heat for 2.0 hours; wet 100C heat for 30 minutes

A. Dry 200C heat for 1.5 hours; wet 121C heat for 15 minutes

21. Which of the following is not a sterilization method?
A. Hot air oven

B. Autoclave

C. Pasteurization

D. Filtration

C. Pasteurization

22. Which of the following methods sterilize the materials?
A. Pasteurization
B. High-temperature-short-time pasteurization (HTST)
C. Ultrahigh-temperature (UHT) method
D. None of these are sterilization methods.

C. Ultrahigh-temperature (UHT) method

23. The autoclave treatment may be monitored by
A. heat-sensitive tape.
B. heat-resistant endospores of Geobacillus stearothermophilus.
C. pressure indicators alone.
D. waiting for contaminants to appear on freshly poured media.
E. heat-sensitive tape AND heat-resistant endospores of Geobacillus stearothermophilus.

E. heat-sensitive tape AND heat-resistant endospores of Geobacillus stearothermophilus.

24. Commercial canning processes
A. are geared to destroy Clostridium botulinum spores.
B. kill all endospores.
C. are especially needed on low acid foods.
D. are 12D processes (designed to kill 10¹² endospores).
E. are geared to destroy Clostridium botulinum spores, are especially needed on low acid foods, AND are 12D (designed to kill 10¹² endospores) processes.

E. are geared to destroy Clostridium botulinum spores, are especially needed on low acid foods, AND are 12D (designed to kill 10¹² endospores) processes.

25. Oxidation of proteins is achieved most readily
A. by moist heat.
B. by moist heat under pressure.
C. in a hot air oven.
D. in the presence of organics.

C. in a hot air oven.

26. A common application of dry heat in the microbiology laboratory is to
A. prepare specimens for study.
B. sterilize media.
C. sterilize plastics.
D. sterilize the inoculating loop.

D. sterilize the inoculating loop.

27. Liquid media containing heat-sensitive components would best be sterilized by
A. ultraviolet (UV) light at 500 nm.

B. freezing.
C. lyophilization.
D. membrane filtration.

D. membrane filtration.

28. Generally, membrane filters are not used to remove
A. bacteria from liquids.
B. microorganisms from gases.
C. spoilage agents from alcoholic beverages.
D. enzymes.

D. enzymes.

29. Gamma rays cause biological damage in living systems by
A. producing reactive molecules such as superoxide and hydroxyl-free radicals.

B. causing tiny gravity sinks and black holes to be formed in the substance.
C. introducing toxins.
D. making the substance radioactive.

A. producing reactive molecules such as superoxide and hydroxyl-free radicals.

30. Gamma irradiation
A. has not been approved for use on food.
B. can be used to either sterilize or pasteurize, depending on the dose of radiation.
C. leaves some radioactive particles in the treated substance.
D. usually kills by generating heat and denaturing proteins.

B. can be used to either sterilize or pasteurize, depending on the dose of radiation.

31. Which would be most effective against Pseudomonas?
A. Alcohol

B. Radiation

C. Quaternary ammonium compounds

D. Iodophors

B. Radiation

32. Ultraviolet radiation at the bactericidal wavelength destroy bacteria by
A. destroying endospores.
B. damaging nucleic acid.
C. preventing spore formation.
D. denaturing proteins.

B. damaging nucleic acid.

33. Microwaves do not kill organisms directly but kill by
A. the heat they generate in a product.
B. generating free radicals.
C. generating toxins.
D. creating thymine dimers.

A. the heat they generate in a product.

34. Chemical germicides
A. may react irreversibly with proteins/enzymes.
B. may react with cytoplasmic membranes or viral envelopes.
C. may be disinfecting or even sterilizing.
D. are sensitive to dilution factor, time of contact, and temperature of use.
E. All of the choices are true.

E. All of the choices are true.

35. Alcohols are not reliably effective at destroying
A. vegetative bacteria.
B. enveloped viruses.
C. non-enveloped viruses.

D. endospores.
E. non-enveloped viruses AND endospores.

E. non-enveloped viruses AND endospores.

36. Glutaraldehyde
A. is, if given enough time, able to destroy all forms of microbial life.
B. is very good for use on heat-sensitive medical items.
C. attacks lipids.
D. does not affect non-enveloped viruses.

E. is, if given enough time, able to destroy all forms of microbial life AND is very good for use on heat-sensitive medical items.

E. is, if given enough time, able to destroy all forms of microbial life AND is very good for use on heat-sensitive medical items.

37. Chlorhexidine
A. is a member of the biguanides.
B. is extensively used in antiseptics.
C. is ineffective against vegetative bacteria.
D. is limited in use due to its high toxicity.
E. is a member of the biguanides AND is extensively used in antiseptics.

E. is a member of the biguanides AND is extensively used in antiseptics.

38. Ethylene oxide is gas that
A. is very useful for sterilizing heat or moisture-sensitive items.

B. is potentially carcinogenic.
C. is used as a 37% aqueous solution.
D. is effective against all microorganisms except endospores and viruses.
E. is very useful for sterilizing heat or moisture-sensitive items AND is potentially carcinogenic.

E. is very useful for sterilizing heat or moisture-sensitive items AND is potentially carcinogenic.

39. Chlorine
A. readily reacts with organics to produce potentially carcinogenic trihalomethanes.
B. is an effective, inexpensive, disinfectant able to destroy all types of microorganisms.
C. is unaffected by the presence of organic material.
D. is ineffective when diluted.
E. readily reacts with organics to produce potentially carcinogenic trihalomethanes AND is an effective, inexpensive, disinfectant able to destroy all types of microorganisms.

E. readily reacts with organics to produce potentially carcinogenic trihalomethanes AND is an effective, inexpensive, disinfectant able to destroy all types of microorganisms.

40. Which is true of iodine?
A. It does not readily kill endospores.
B. It may be used as an antiseptic or as a disinfectant.
C. It is important to use it at the recommended dilution.
D. It is usually found as tinctures or iodophors.
E. All of the choices are true.

E. All of the choices are true.

41. Which of the following is true of hydrogen peroxide?
A. It is a sterilant for inanimate objects and is quickly inactivated on living tissue.
B. It leaves a toxic residue.
C. It is broken down by catalase into water and oxygen.
D. It is even more effective when used in combination with peracetic acid.
E. It is a sterilant for inanimate objects and is quickly inactivated on living tissue; it is broken down by catalase into water and oxygen; AND it is even more effective when used in combination with peracetic acid.

E. It is a sterilant for inanimate objects and is quickly inactivated on living tissue; it is broken down by catalase into water and oxygen; AND it is even more effective when used in combination with peracetic acid.

42. Phenolics
A. denature proteins and destroy cytoplasmic membranes.
B. remain effective in the presence of detergents or organic material.
C. such as triclosan, have been used widely in various lotions and soaps.
D. reliably inactivate all groups of viruses.
E. denature proteins and destroy cytoplasmic membranes, remain effective in the presence of detergents or organic material, AND phenolics such as triclosan, have been used widely in various lotions and soaps.

E. denature proteins and destroy cytoplasmic membranes, remain effective in the presence of detergents or organic material, AND phenolics such as triclosan, have been used widely in various lotions and soaps.

43. Hexachlorophene has been particularly effective against
A. Staphylococcus aureus.
B. Micrococcus aureus.
C. Escherichia coli.
D. Enterobacter aerogenes.

A. Staphylococcus aureus.

44. Quaternary ammonium compounds are
A. cationic detergents that help wash surfaces.

B. attracted to the negative charge on the microbial cell surface.
C. used as a 37% aqueous solution.
D. very effective against Pseudomonas.
E. cationic detergents that help wash surfaces AND attracted to the negative charge on the microbial cell surface.

E. cationic detergents that help wash surfaces AND attracted to the negative charge on the microbial cell surface.

45. Which of the following is(are) considered when selecting a germicidal chemical?
A. Toxicity

B. Cost

C. Compatibility with the material being treated

D. Environmental impact

E. All of the choices are correct.

E. All of the choices are correct.

46. Silver sulfadiazine, a combination of silver and a sulfa drug, is used to
A. disinfect water for drinking.
B. prevent infection of surgical wounds.
C. prevent infection of second- and third-degree burns.
D. counteract lead poisoning.
E. treat bites from werewolves.

C. prevent infection of second- and third-degree burns.

47. Compounds of tin, mercury, arsenic, and copper are no longer used to prevent microbial growth in cooling water primarily because
A. antibiotics are cheaper.
B. other chemicals were shown to be much more effective.
C. microbes developed resistance to these metals.
D. their use contributes to serious pollution of natural waters.
E. All of the choices are correct.

D. their use contributes to serious pollution of natural waters.

48. The most important function of nitrites in processed foods is to
A. prevent browning.
B. inhibit the germination of Clostridium botulinum endospores.
C. prevent carcinogen formation.
D. make the food more acidic.

B. inhibit the germination of Clostridium botulinum endospores.

1. One of the earliest researchers to explore the use of chemicals to kill microbial pathogens was
A. Koch.
B. Hooke.
C. Fleming.
D. Ehrlich.

D. Ehrlich.

2. The arsenic compound that proved highly effective in treating syphilis was called
A. penicillin.
B. sulfa.
C. erythromycin.
D. Salvarsan.

D. Salvarsan.

3. The first example of an antimicrobial drug synthesized in the laboratory was
A. penicillin.
B. sulfa.
C. erythromycin.
D. Salvarsan.

D. Salvarsan.

4. Prontosil effectively acted on streptococci when the drug was split by enzymes to produce
A. penicillin.
B. sulfanilamide.
C. erythromycin.
D. Salvarsan.

B. sulfanilamide.

5. The use of Salvarsan and Prontosil to treat microbial infections were early examples of
A. antibiotics.
B. toxins.
C. inhibitors.
D. chemotherapy.

D. chemotherapy.

6. Penicillin was discovered by
A. Koch.
B. Hooke.
C. Fleming.
D. Ehrlich.

C. Fleming.

7. The most effective form of penicillin is
A. A.
B. B.
C. E.
D. G.

D. G.

8. One of the earliest antimicrobials isolated from a bacterium was
A. penicillin.
B. ampicillin.
C. Salvarsan.
D. streptomycin.

D. streptomycin.

9. Which of the following groups of microorganisms produces antibiotics?
A. Penicillium
B. Streptomyces
C. Bacillus
D. Penicillium AND Streptomyces
E. All of the choices are correct.

E. All of the choices are correct.

10. An antibiotic made by microorganisms and modified by chemists is called
A. anti-metabolic.
B. catabolic.
C. synthetic.
D. semi-synthetic.

D. semi-synthetic.

11. The antimicrobials produced by some molds and bacteria are generally called
A. insecticides.
B. biocides.
C. antiseptics.
D. antibiotics.

D. antibiotics.

12. The toxicity of a given drug is expressed as the
A. selective toxicity.
B. biocide index.
C. biostatic index.
D. therapeutic index.

D. therapeutic index.

13. A high therapeutic index is
A. more toxic to the patient.
B. less toxic to the patient.
C. has no effect on the patient.
D. has no effect on the pathogen.

B. less toxic to the patient.

14. Drugs that are bacteriostatic
A. kill bacteria.
B. promote bacterial growth.
C. inactivate bacterial spores.
D. inhibit the growth of bacteria.

D. inhibit the growth of bacteria.

15. Antimicrobials that kill microorganisms have the suffix
A. -cidal.
B. -static.
C. -anti.
D. -genic.

A. -cidal.

16. Antimicrobials that inhibit the growth of microorganisms have the suffix
A. -cidal.
B. -static.
C. -anti.
D. -genic.

B. -static.

17. Antibiotics that affect various strains of Gram-positive bacteria and various strains of Gram-negative bacteria are called

A. isolate usable.
B. stress-induced.
C. narrow-spectrum.
D. broad-spectrum.

D. broad-spectrum.

18. The rate of elimination of an antimicrobial is expressed as its
A. metabolic destructive rate.
B. half-life.
C. effective time.
D. dosage rate.

B. half-life.

Antibiotics that are most likely to disrupt the normal microbiota are termed

A. narrow-spectrum.
B. broad-spectrum.
C. targeted spectrum.
D. semi-synthetic.

B. broad-spectrum.

20. Drugs that are more effective when taken together are called
A. energetic.
B. antagonistic.
C. subtractive.
D. synergistic.

D. synergistic.

21. If drugs are less effective when taken together than when each is taken separately, they are called
A. energetic.
B. antagonistic.
C. additive.
D. synergistic.

B. antagonistic.

22. Antimicrobials may produce
A. allergic reactions.
B. toxic effects.
C. suppression of normal microbiota.

D. All of the choices are correct.

D. All of the choices are correct.

23. Which of the following bacteria have an innate resistance to penicillin?
A. S. aureus
B. S. epidermidis
C. M. luteus
D. Mycoplasma

D. Mycoplasma

24. Which of the following drugs target peptidoglycan?
A. Penicillin

B. Cephalosporin

C. Vancomycin

D. Bacitracin

E. All of the choices are correct.

E. All of the choices are correct.

25. All members of the penicillin family have
A. beta-lactam rings.
B. alpha-lactam rings.
C. phenolic rings.
D. sulfanilic rings.

A. beta-lactam rings.

26. Penicillin-binding proteins
A. primarily function in the cell to bind to beta-lactam drugs.
B. are enzymes.
C. are involved in cell wall synthesis.
D. inhibit non-growing bacteria.
E. are enzymes AND are involved in cell wall synthesis.

E. are enzymes AND are involved in cell wall synthesis.

27. Beta-lactamases
A. bind to penicillin-binding proteins.
B. bind to peptides.
C. prevent the linking of glycan chains in peptidoglycan.
D. break the beta-lactam ring.

D. break the beta-lactam ring.

28. The major class(es) of antibiotics that inhibit protein synthesis is/are
A. aminoglycosides.
B. tetracyclines.
C. macrolides.
D. bacitracins.
E. aminoglycosides, tetracyclines, AND macrolides.

E. aminoglycosides, tetracyclines, AND macrolides.

29. Inhibitors of protein synthesis typically key on
A. peptidoglycan precursors.
B. penicillin-binding proteins.
C. ribosomes.
D. porin proteins.

C. ribosomes.

30. Which is true of aminoglycosides?
A. They are bacteriostatic.
B. They irreversibly bind to the 30S ribosomal subunit.
C. They block peptidoglycan synthesis.
D. They are bactericidal.
E. They irreversibly bind to the 30S ribosomal subunit AND they are bactericidal.

E. They irreversibly bind to the 30S ribosomal subunit AND they are bactericidal.

31. Fluoroquinolones typically target
A. ribosomes.
B. penicillin-binding proteins.
C. peptidoglycan.
D. DNA gyrase.

D. DNA gyrase.

32. Sulfonamide and trimethoprim are both
A. examples of metabolic inhibitors.
B. folate inhibitors.
C. protein synthesis inhibitors.
D. inhibitors of cell wall synthesis.
E. examples of metabolic inhibitors AND folate inhibitors.

E. examples of metabolic inhibitors AND folate inhibitors.

33. Folic acid is ultimately used in the synthesis of
A. topoisomerases.
B. proteins.
C. DNA gyrases.
D. sulfonamides.
E. coenzymes.

E. coenzymes.

34. Sulfonamides are similar in structure to
A. DNA gyrases.
B. LPS.
C. ribosomes.
D. PABA.

D. PABA.

35. Sulfonamides work as
A. competitive inhibitors.
B. noncompetitive inhibitors.
C. ribosome-binding molecules.
D. feedback inhibitors.

A. competitive inhibitors.

36. Trimethoprim and sulfonamides have a(n)
A. antagonistic effect.
B. synergistic effect.
C. energetic effect.
D. subtractive.

B. synergistic effect.

37. Mycolic acids are targeted by isoniazid in the treatment of
A. S. aureus.
B. S. epidermidis.
C. M. luteus.
D. M. tuberculosis.

D. M. tuberculosis.

38. The lowest concentration of a drug that prevents growth of a microorganism is the
A. infectious dose.
B. lethal dose.
C. effective dose.
D. minimum inhibitory concentration.

D. minimum inhibitory concentration.

39. The minimum bactericidal concentration is the lowest concentration of a specific antimicrobial drug that kills _______ of a specific type of bacteria.
A. 10%
B. 50%
C. 99.9%
D. 100%

C. 99.9%

40. The diffusion bioassay
A. determines the concentration of antimicrobial necessary to kill a bacteria.
B. determines the concentration of antimicrobial necessary to inhibit growth of a bacteria.
C. is similar in principle to the Kirby-Bauer test.

D. determines the concentration of antimicrobial in a fluid

E. is similar in principle to the Kirby-Bauer AND determines the concentration of antimicrobial in a fluid.

E. is similar in principle to the Kirby-Bauer AND determines the concentration of antimicrobial in a fluid.

41. Which test is used to determine the susceptibility of a microorganism to an antimicrobial?
A. MIC
B. MIB
C. MLB
D. Kirby-Bauer test

D. Kirby-Bauer test

42. The zone size obtained in the Kirby-Bauer test is influenced by the drug's
A. size.
B. stability.
C. concentration.
D. All of the choices are correct.

D. All of the choices are correct.

43. A commercial modification of the disk diffusion test is called the
A. A test.
B. B test.
C. C test.
D. D test.
E. E test.

E. E test.

44. Bacteria may become antibiotic resistant due to
A. drug-inactivating enzymes.
B. alteration in the target molecule.
C. decreased uptake of the drug.
D. increased elimination of the drug.
E. All of the choices are correct.

E. All of the choices are correct.

45. Spontaneous development of resistance to a particular antimicrobial is difficult if the drug
A. binds to several sites on the target molecule.
B. targets several different molecules.
C. affects only one molecule.
D. affects the plasma membrane.
E. binds to several sites on the target molecule AND targets several different molecules.

E. binds to several sites on the target molecule AND targets several different molecules.

46. The most common method of transfer of antimicrobial resistance is through the use of
A. viruses.
B. R plasmids.
C. introns.
D. exons.

B. R plasmids.

47. Compliance problems are leading to a large increase in antibiotic resistant strains of
A. Streptococcus.
B. Staphylococcus.
C. Mycobacterium.
D. Pseudomonas.

C. Mycobacterium.

48. Antiviral drugs may target
A. uncoating.
B. nucleic acid synthesis.
C. viral assembly.
D. viral ribosomes.
E. uncoating, nucleic acid synthesis, AND viral assembly.

E. uncoating, nucleic acid synthesis, AND viral assembly.

49. The target of most antifungal drugs is
A. the ribosome.
B. nucleus.
C. cholesterol.
D. ergosterol.
E. cholesterol AND ergosterol.

D. ergosterol.