Test Bank Docx 1e Chapter.13 Control Of Microbial Growth

Chapter 13: Control of Microbial Growth

= Correct answer

Multiple Choice

1. Which of the following is not an example of a fomite?
2. catheter
3. doorknob
4. mosquitoes
5. towels

Difficulty: Easy

ASM Standard: 13, 14, 23

1. HEPA filters are required for which Biological Safety Level (BSL)?
2. BSL 1
3. BSL 2
4. BSL 3
5. BSL 4

Difficulty: Easy

ASM Standard: 14, 37

1. From a clinical perspective, aseptic technique is carried out to do which of the following?
2. clean fomites
3. contaminate fomites
4. introduce contamination in living tissue
5. prevent contamination in living tissue

Difficulty: Easy

ASM Standard: 36, 37

1. The autoclave uses which of the following mechanism(s) for sterilization?
2. pressure
3. temperature
4. pressure and temperature
5. pressure, temperature, and pH

Difficulty: Easy

ASM Standard: 14, 36, 37

1. Autoclaves are designed to kill which of the following heat-resistant microbes?
2. endospores
3. prions
4. vegetative bacterial and fungal cells
5. viruses

Difficulty: Easy

ASM Standard: 14, 36, 37

1. The decimal reduction time (D-value) is how long it takes to kill which percentage of a microbial population?
2. 10%
3. 50%
4. 90%
5. 100%

Difficulty: Moderate

ASM Standard: 14

1. Which of the following actions would be most clearly considered bacteriostatic rather than bactericidal?
2. autoclaving bacterial cultures
3. placing a bacterial culture in the −80 °C freezer
4. spraying 70% alcohol on a laboratory bench
5. treating a mattress with ethylene oxide

Difficulty: Moderate

ASM Standard: 14

1. Microbial death follows which type of trend?
2. linear
3. logarithmic
4. power series
5. variable

Difficulty: Moderate

ASM Standard: 14

1. Which of the following are the standard conditions for an autoclave?
2. 100 °C, 1 psi, 60 minutes
3. 121 °C, 1 psi, 60 minutes
4. 121 °C, 15 psi, 20 minutes
5. 212 °C, 15 psi, 10 minutes

Difficulty: Moderate

ASM Standard: 14, 36, 37

1. Which of the following is not a milkborne pathogen?
2. Escherichia coli O157:H7
3. Listeria monocytogenes
4. Salmonella enterica
5. Yersinia pestis

Difficulty: Moderate

ASM Standard: 23

1. For appropriate food storage in refrigerators, the temperature should be set to no higher than which of the following?
2. 5 °C
3. 7 °C
4. 9 °C
5. 11 °C

Difficulty: Easy

ASM Standard: 14

1. How does pascalization control microbial growth?
2. by cross-linking proteins
3. by damaging DNA
4. by denaturing proteins
5. by disrupting membrane integrity

Difficulty: Moderate

ASM Standard: 14

1. X-rays and gamma rays are examples of which type of radiation?
2. beta emission radiation
3. ionizing radiation
4. nonionizing radiation
5. nonpenetrating radiation

Difficulty: Easy

ASM Standard: 14

1. Ultraviolet light is an example of which type of radiation?
2. beta emission radiation
3. ionizing radiation
4. nonionizing radiation
5. penetrating radiation

Difficulty: Easy

ASM Standard: 14

1. To sterilize packaged intravenous tubing, which method would not be acceptable?
2. ethylene oxide
3. freezing
4. ionizing radiation
5. nonionizing radiation

Difficulty: Moderate

ASM Standard: 14, 36

1. Liquid growth media that contain antibiotics should be sterilized using which method?
2. autoclaving
3. boiling
4. HEPA filtration
5. membrane filtration

Difficulty: Easy

ASM Standard: 14, 36

1. Which method of microbial control introduces double-strand breaks into DNA?
2. alcohols
3. autoclaving
4. ionizing radiation
5. nonionizing radiation

Difficulty: Easy

ASM Standard: 14

1. Which method of microbial control does not rely on denaturing proteins and/or disrupting the integrity of the cell membrane?
2. autoclaving
3. lyophilization
4. treatment with alcohols
5. treatment with phenolics

Difficulty: Moderate

ASM Standard: 14

1. Phenolic compounds can be found naturally in which group of organisms?
2. animals
3. bacteria
4. fungi
5. plants

Difficulty: Easy

ASM Standard: N/A

1. Which phenolic compound has commonly been added to soap and raises concerns about selection for more antimicrobial-resistant bacteria?
2. capsaicin
3. carbolic acid
4. o-phenylphenol
5. triclosan

Difficulty: Moderate

ASM Standard: 3, 14

1. Which best describes how heavy metals can control microbial growth?
2. by binding to sulfur-containing amino acids
3. by cross-linking proteins
4. by introducing double-strand breaks into DNA
5. by inserting pores in the cell membrane

Difficulty: Moderate

ASM Standard: 14

1. What is argyria?
2. a buildup of silver in the body resulting in blue-gray skin
3. a form of skin necrosis due to topical use of phenolics
4. inadequate blood supply resulting in chest pain
5. microorganisms growing in the blood

Difficulty: Moderate

ASM Standard: N/A

1. Which halogen or halogen-containing compound is typically used as a form of topical antisepsis?
2. bromine
3. chloramine
4. fluorine
5. iodophor

Difficulty: Easy

ASM Standard: 14, 37

1. All but which of the following may be used to disinfect water to make it potable?
2. bleach
3. chloramine
4. fluoride
5. sodium dichloroisocyanurate

Difficulty: Easy

ASM Standard: 14, 23

1. Contact lens cleaners commonly use which type of chemical agent to control microbial growth?
2. alkylating agents
3. peroxygen
4. quats
5. supercritical fluid

Difficulty: Easy

ASM Standard: 14

1. Which of the following is not an alkylating agent?
2. chlorhexidine
3. ethylene oxide
4. formalin
5. o-phenylphenol

Difficulty: Moderate

ASM Standard: 14

1. Many chemical preservatives, such as potassium sorbate, preserve food products in which of the following ways?
2. by altering the pH
3. by binding to pathogens
4. by changing the osmolarity
5. by drying foods

Difficulty: Easy

ASM Standard: 14

1. Nisin is an antimicrobial peptide produced by which bacterium?
2. Lactobacillus acidophilus
3. Lactococcus lactis
4. Listeria monocytogenes
5. Streptomyces natalensis

Difficulty: Easy

ASM Standard: 14, 26

1. Examine the disk-diffusion assay shown below. Which antimicrobial agent is the least effective?

1. A
2. B
3. C
4. D

Difficulty: Moderate

ASM Standard: 14, 28b

30. Which of the following is used to determine if a solution of disinfectant actively used in the clinical setting is contaminated?

the disk-diffusion method

the in-use test

the phenol coefficient test

1. the use-dilution test

Difficulty: Moderate

ASM Standard: 14, 36

True/False

1. Commercial sterilization kills all microbes.

Difficulty: Easy

ASM Standard: 14

1. Pasteurized foods cannot spoil.

Difficulty: Easy

ASM Standard: 14

1. Autoclaves use moist heat to sterilize materials.

Difficulty: Easy

ASM Standard: 14

1. X-rays and gamma rays are examples of ionizing radiation and cause the formation of thymine dimers.

Difficulty: Moderate

ASM Standard: 14

35. Mercury compounds may be dissolved in alcohol and used as tinctures.

Difficulty: Easy

ASM Standard: 14

1. HEPA filters are able to filter many airborne virions.

Difficulty: Easy

ASM Standard: 14

1. Quats are not effective against endospores and prions.

Difficulty: Difficult

ASM Standard: 14

1. Quats are anionic compounds.

Difficulty: Moderate

ASM Standard: 14

1. Soaps with no added ingredients are bactericidal.

Difficulty: Easy

ASM Standard: 14

1. Sonication causes cavitation in cells.

Difficulty: Easy

ASM Standard: 14

Matching

1. Match the medical instrument to its proper classification.

Note than an answer may be used more than once.

Answers: A. i., B. ii., C. ii., D. iii., E. iii.

Difficulty: Moderate

ASM Standard: N/A

1. Match the microbial growth control term with its correct definition.

Answers: A. ii., B. i., C. v., D. iii., E. iv.

Difficulty: Moderate

ASM Standard: 14

1. Match the agent to its mechanism of action.

Answers: A. iv., B. ii., C. iii., D. i.

Difficulty: Moderate

ASM Standard: 14

1. Match the agent to the mechanism of action.

Answers: A. i., B. iii., C. iv., D. ii.

Difficulty: Moderate

ASM Standard: 14

Fill in the Blank

1. The complete removal of vegetative cells, endospores, and viruses is known as ________.

Difficulty: Easy

ASM Standard: 14

1. Traditional pasteurization kills pathogens and reduces the number of ________ while maintaining food quality.

Difficulty: Easy

ASM Standard: 14, 23

1. A microbiology laboratory that works with many indigenous environmental samples would be classified as a Biological Safety Lab (BSL) ________.

Difficulty: Moderate

ASM Standard: 37

1. ________ is the appropriate method to pasteurize milk for areas where the milk cannot be refrigerated.

Difficulty: Moderate

ASM Standard: 14

1. Food items are irradiated using ________ radiation.

Difficulty: Moderate

ASM Standard: 14

1. Prior to the use of antibiotics, newborns were routinely treated with ________ upon birth as protection against bacterial infection they may have acquired during passage through the birth canal.

Difficulty: Easy

ASM Standard: 14, 23

1. Recently, the heavy metal ________ has been used in designing pots for water storage to reduce diarrheal diseases.

Difficulty: Easy

ASM Standard: 14, 23

1. ________ is a gaseous alkylating agent used to sterilize objects, like bed mattresses, that cannot be autoclaved.

Difficulty: Moderate

ASM Standard: 14

1. Some bacteria and other organisms produce the enzyme ________, which catalyzes the reaction .

Difficulty: Easy

ASM Standard: 14

1. A recently developed method of antisepsis that can be used on skin before transplantation is ________.

Difficulty: Moderate

ASM Standard: 14

Short Answer

1. What is the difference between a disinfectant and an antiseptic?

Sample

Difficulty: Easy

ASM Standard: 14

1. Which heat method (dry or moist) is more effective? Why?

Sample

Difficulty: Easy

ASM Standard: 14

1. Name two quality-control methods/indicators used to determine if something has been autoclaved properly.

Sample

Difficulty: Easy

ASM Standard: 36, 37

1. Is desiccation a “-cidal” mechanism and what effect does it have on microbes?

Sample

Difficulty: Moderate

ASM Standard: 13, 14

1. Why is it rare to hear about foodborne disease outbreaks from the consumption of candy bars?

Sample

Difficulty: Moderate

ASM Standard: 13, 14

1. An experiment is conducted to see how many bacteria remain in a culture at different times and temperatures. The data are shown below.
2. What is the lowest temperature that represents the thermal death point?
3. What is the thermal death time at 67 °C?

Sample

Difficulty: Moderate

ASM Standard: 13, 14, 28b

1. How does nonionizing radiation cause mutations in DNA?

Sample

Difficulty: Moderate

ASM Standard: 14

1. What is the mode of action for iodine?

Sample

Difficulty: Moderate

ASM Standard: 14

1. What is the mode of action for alcohols?

Sample

Difficulty: Moderate

ASM Standard: 14

1. Name two chemical food preservatives that are naturally produced by microorganisms.

Sample

Difficulty: Easy

ASM Standard: 14, 26

1. Name one benefit of using quats.

Answers will vary. Quats are stable, nontoxic, inexpensive, colorless, odorless, and tasteless. They are also active against fungi, protozoans, and enveloped viruses. They may be used as antiseptics or disinfectants.

Difficulty: Moderate

ASM Standard: 14

Questions 66 and 67 are based on the following experiment:

Different disinfectants are soaked on sterile pads that are then placed on a lawn of bacteria. The photo below shows the results after 24 hours of incubation.

1. What assay is being shown here?

Sample

Difficulty: Easy

ASM Standard: 14, 36

1. Which antimicrobial agent (A through F) is the most effective against the bacteria that were plated?

Sample

Difficulty: Easy

ASM Standard: 28b, 38

Questions 68 and 69 are based on the following experiment:

You wish to test the efficacy of a disinfectant that has been used to clean hospital rooms. The diagram below shows the experimental setup and the results.

1. What assay is being shown here?

Sample

Difficulty: Easy

ASM Standard: 14, 36

1. What conclusion can you draw from the results of this experiment?

Sample

Difficulty: Moderate

ASM Standard: 28b, 38

Brief Essay

Essay Question Rubric

Assume rating/grading scale for the question ranges from 0 to 3 points.

1. A simple example of controlling microbial growth is based on how we handle our food products. Name three food preparation methods that counter microbial growth. Be sure to discuss the mode of action for each method.

Difficulty: Difficult

ASM Standard: 14

1. A company has hired you and your laboratory to test the efficacy of a new alkylating agent, “Substance X.” You prepare a culture of endospores and add Substance X. Every 5 minutes, you plate the endospores to see if they are still viable. The data from this experiment are shown below.

A. What is the mode of action for Substance X?

B. State the independent and dependent variables of this experiment.

C. Prepare a graph of these data using a logarithmic scale for the y-axis and a linear sale for the x-axis.

D. What is the approximate decimal reduction time (D-value) of Substance X against the endospores used?

E. Would you classify Substance X as a high-, intermediate- or low-level germicide? Why?

Difficulty: Difficult

ASM Standard: 14, 28b, 29, 29a, 38

1. Explain how hyperbaric oxygen therapy works. What types of bacterial infections can be treated with hyperbaric oxygen?

Difficulty: Moderate

ASM Standard: 13, 14, 23

1. Name two chemical preservatives and state their modes of action. Be sure to indicate whether they target bacteria and/or fungi.

Difficulty: Difficult

ASM Standard: 13, 14

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