Deck 9: Controlling Microbial Growth in the Environment

Question 1

Which of the following can be used to disinfect air?

A) HEPA filters
B) ethylene oxide
C) ultraviolet light
D) both HEPA filters and ultraviolet light
E) both ethylene oxide and ultraviolet light

Answer 1

D

Question 2

Which of the following is NOT a feature associated with filtration?

A) nitrocellulose or plastic membrane filters
B) sterilization of heat-sensitive materials
C) varying thicknesses of membrane filters used
D) use of HEPA filters to filter air
E) ability of some filters to trap viruses and proteins

Answer 2

C

Question 3

The dairy creamer used in restaurants is usually sterilized by

A) filtration.
B) ionizing radiation.
C) lyophilization.
D) UHT sterilization.
E) autoclaving.

Answer 3

D

Question 4

Which of the following is the most appropriate pairing of microbe and biosafety level?

A) E. coli, BSL-3
B) anthrax, BSL-1
C) Ebola, BSL-2
D) methicillin-resistant Staphylococcus aureus (MRSA), BSL-2
E) tuberculosis, BSL-1

Question 5

Lysol is an example of which of the following groups of chemical antimicrobial agents?

A) halogens
B) phenolics
C) alcohols
D) aldehydes
E) surfactants

Question 6

Which of the following types of radiation is nonionizing and has the shortest wavelength?

A) ultraviolet light
B) infrared radiation
C) microwaves
D) X rays
E) gamma rays

Question 7

Standard methods of sterilization are not effective in inactivating

A) viruses.
B) bacterial cells.
C) prions.
D) bacterial endospores.
E) fungi.

Question 8

Which of the following is a target of pasteurization?

A) Bacillus stearothermophilus
B) Clostridium botulinum
C) Neisseria gonorrhoeae
D) Chlamydia trachomatis
E) Brucella melitensis

Question 9

Which of the following is an example of sanitization?

A) A public toilet is treated with disinfectants.
B) A surgeon washes her hands before surgery.
C) Heat is used to kill potential pathogens in apple juice.
D) An autoclave is used to prepare nutrient agar.
E) A nurse prepares an injection site with an alcohol swab.

Question 10

Which of the following would NOT be bacteriostatic?

A) desiccation
B) freezing below 0°C
C) lyophilization
D) autoclaving
E) refrigeration of mesophiles

Question 11

Aseptic means

A) sterile.
B) free of all microbes.
C) clean.
D) sanitized.
E) free of pathogens.

Question 12

Which of the following is NOT an effective means of sterilization?

A) ionizing radiation
B) incineration
C) lyophilization
D) autoclaving
E) dry heat

Question 13

An instrument that will come into contact with only the skin of a patient should be disinfected with a(n)

A) high-level germicide.
B) low-level germicide.
C) intermediate-level germicide.
D) degerming agent only.
E) germistatic agent only.

Question 14

Antimicrobial agents that damage nucleic acids also affect

A) the cell wall.
B) the cell membrane.
C) the viral envelope.
D) endospores.
E) protein synthesis.

Question 15

Which of the following statements is true of disinfectants?

A) Disinfectants are effective in destroying endospores.
B) Disinfectants are used on living tissue.
C) Disinfectants are used for sterilization.
D) Disinfectants are used on inanimate surfaces.
E) Disinfectants are only effective for short periods of time (seconds to minutes).

Question 16

Which of the following describes flash pasteurization?

A) heating at 63°C for 30 minutes
B) heating at 72°C for 15 seconds
C) heating at 72°C for 15 minutes
D) heating at 134°C for one second
E) passing liquid through steam at 140°C

Question 17

Boiling water for 10 minutes is effective in ridding it of

A) actively growing bacteria.
B) enveloped viruses.
C) bacterial endospores.
D) protozoan cysts.
E) both growing bacteria and enveloped viruses.

Question 18

Seventy percent alcohol is effective against

A) enveloped viruses.
B) nonenveloped viruses.
C) bacterial endospores.
D) protozoan cysts.
E) prions.

Question 19

Which of the following statements concerning microbial death is FALSE?

A) It can be used to evaluate the efficacy of antimicrobial agents.
B) It is constant over time of exposure to an antimicrobial agent.
C) It is the permanent loss of a microbe's reproductive ability.
D) It is the permanent loss of a microbe's ability to reproduce and can be used to evaluate antimicrobial agents.
E) It is not an effective means of evaluating the efficacy of antimicrobial agents.

Question 20

Which of the following is used for microbial control in fresh fruits and vegetables?

A) X rays
B) ultraviolet light
C) electron beams
D) microwaves
E) gamma rays

Question 21

Which of the following antimicrobial agents is the most toxic to humans?

A) 70% alcohol
B) ethylene oxide
C) quats
D) chloramines
E) iodophors

Question 22

Which of the following is NOT a desirable characteristic of an ideal antimicrobial agent?

A) it is inexpensive.
B) it is stable during storage.
C) it is harmless to humans.
D) it only arrests growth of vegetative cells.
E) it acts quickly.

Question 23

Disinfectants that damage membranes include

A) alcohol.
B) phenolics.
C) iodine.
D) hydrogen peroxide.
E) both alcohol and phenolics.

Question 24

The process of filtration is a(n)

A) disinfectant method.
B) sterilizing method.
C) sanitization method.
D) antiseptic procedure.
E) ineffective method for removing microbes.

Question 25

The endospores of which of the following microbes are used to measure the effectiveness of autoclave sterilization?

A) Clostridium botulinum
B) Neisseria gonorrhoeae
C) Bacillus stearothermophilus
D) Pseudomonas aeruginosa
E) Mycobacterium bovis

Question 26

Which of the following statements about aldehydes is FALSE?

A) They are used only to preserve dead tissues.
B) They denature proteins.
C) Some aldehydes can sterilize after long periods of exposure.
D) They are usually hazardous to humans.
E) They are used in aqueous solutions.

Question 27

The process of incineration is used for

A) sterilization.
B) disinfection.
C) sanitization.
D) both disinfection and sanitization.
E) degerming.

Question 28

Which of the following procedures is currently the standard test used in the United States for evaluating the efficiency of antiseptics and disinfectants?

A) use-dilution test
B) microbial death rate
C) in-use test
D) thermal death point
E) phenol coefficient

Question 29

Which of the following is used to sterilize items that should not, or cannot, be exposed to heat or water?

A) ethylene oxide
B) formaldehyde
C) hydrogen peroxide
D) calcium hypochlorite
E) triclosan

Question 30

Disinfecting agents naturally produced by microorganisms are

A) aldehydes.
B) antimicrobials.
C) halogens.
D) quats.
E) triclosans.

Question 31

Betadine is an example of which of the following groups of antimicrobial agents?

A) alcohols
B) heavy metals
C) halogens
D) phenolics
E) surfactants

Question 32

Hydrogen peroxide is a(n)

A) sterilizing agent.
B) disinfecting agent.
C) antiseptic.
D) disinfecting and sterilizing agent.
E) ineffective method of disinfecting.

Question 33

Which of the following statements about quaternary ammonium compounds is FALSE?

A) They are a type of detergent.
B) Zephiran is an example of a quat.
C) They are not effective against Pseudomonas aeruginosa.
D) They function by cross-linking proteins.
E) They are harmless to humans except at high concentrations.

Question 34

Which of the following was used in the past to prevent the transmission of gonorrhea from an infected mother to her newborn?

A) hydrogen peroxide
B) beta-propiolactone
C) thimerosal
D) hexachlorophene
E) silver nitrate

Question 35

A scientist develops a new medication that is a protein compound and that must be administered by injection. Which of the following would be the most effective and safest means of preparing a sterile solution of the new medication?

A) autoclaving
B) filtration
C) dilution with alcohol
D) lyophilization
E) ultraviolet irradiation

Question 36

Which of the following would be used to sterilize a mattress?

A) autoclaving
B) formaldehyde
C) ethylene oxide
D) heavy metals
E) radiation

Question 37

The chemical agents known as "quats" are used for

A) antisepsis.
B) disinfection.
C) sterilization.
D) quantifying antimicrobial activity.
E) neither antisepsis nor disinfection.

Question 38

A chemical agent that kills pathogenic microbes in general is a(n)

A) sanitizer.
B) germicide.
C) disinfectant.
D) fungicide.
E) antiseptic.

Question 39

Alcohols are used for

A) disinfection.
B) sterilization.
C) antisepsis.
D) both sterilization and disinfection.
E) both antisepsis and disinfection.

Question 40

Which of the following is a sterilizing agent?

A) ozone
B) hydrogen peroxide
C) peracetic acid
D) dish soap
E) ozone and hydrogen peroxide

Question 41

Hydrogen peroxide is an effective antiseptic.

Question 42

The compound ethylene oxide is used in

A) sanitization.
B) sterilization.
C) antisepsis.
D) degerming.
E) disinfection.

Question 43

Disinfectants known as __________ have the chemical group -CHO, which reacts with and damages both proteins and nucleic acids.

Question 44

A(n) __________ is an iodine-containing organic compound found in such antiseptics as Betadine.

Question 45

The phenol coefficient is one of the most widely used measurements of an antimicrobial agent's effectiveness.

Question 46

No chemical or antimicrobial agents inactivate prions.

Question 47

Natural antiseptics such as pine or clove oil are examples of antimicrobial compounds called __________.

Question 48

__________ may be achieved using chlorine dioxide.

A) Disinfection
B) Sterilization
C) Degerming
D) Antisepsis
E) Both antisepsis and degerming

Question 49

The lowest temperature that kills all cells in a broth in 10 minutes is knows as the __________ death point.

Question 50

Antimicrobial agents usually work best at high temperatures and pH levels.

Question 51

__________ can be accomplished using boiling water.

A) Sanitization
B) Disinfection
C) Sterilization
D) Antisepsis
E) Both disinfection and sanitization

Question 52

Some viruses are inactivated by the same chemical or physical agents that damage cytoplasmic membranes.

Question 53

Slow freezing is more damaging to microbial cells than quick freezing.

Question 54

Glutaraldehyde is used for

A) antisepsis.
B) disinfection.
C) sterilization
D) sanitization.
E) both disinfection and sterilization.

Question 55

Gamma irradiation is a process for

A) sterilization.
B) disinfection.
C) antisepsis.
D) degerming.
E) both antisepsis and disinfection.

Question 56

UV light has the most effect on protein structure.

Question 57

The process of freeze-drying microbes to preserve them is __________.

Question 58

An environment may contain some microbes and still be considered sterile.

Question 59

By themselves, soaps have only degerming activity, not antimicrobial activity.

Question 60

The decimal reduction time is the time required to kill all the microbes in a given sample.

Question 61

Triclosan is a(n) __________ antimicrobial compound that has been incorporated into consumer items such as garbage bags and diapers.

Question 62

Ultraviolet light penetrates __________ effectively than gamma rays.

Question 63

BSL-4 is the appropriate __________ level when handling highly contagious deadly microbes.

Question 64

A(n) __________ is an instrument that sterilizes by exposing materials to steam under pressure.

Question 65

Heavy metal and oxidizing agent disinfectants damage __________, interfering with microbial metabolism.

Question 66

A student is shopping for antibacterial hand cleansers and is trying to decide which one to buy. One is a "waterless" hand gel containing 70% isopropanol, the second is an "antibacterial" hand soap containing triclosan (a phenolic), and the third is a wipe that lists benzethonium chloride (a synthetic quaternary ammonium salt) as the active ingredient. Compare and contrast these cleansers in terms of the action of the antimicrobial ingredient and the level of disinfection (degerming, germistatic, germicidal).

Question 67

The use of high levels of salt or sugar in the preservation of food relies on the phenomenon of __________ pressure.

Question 68

Describe the cellular structures or processes that can be targets of antimicrobial agents.

Question 69

Sterilization procedures generally focus on inactivating or eliminating bacterial __________.

Question 70

Elements such as iodine, chlorine, and bromine are examples of __________, which are the basis for many effective antimicrobial agents.

Question 71

Some sterilization procedures do not kill all the microbes that may be present. Explain how these procedures can still be considered sterilization.

Question 72

What is the in-use test, and why is it more useful than other methods of evaluating disinfectants?

Question 73

The process of heating milk or fruit juice to levels that kill any pathogenic microbes present is known as __________.

Question 74

The amount of time needed to sterilize materials using moist heat is __________ than the time needed to sterilize using dry heat.

Question 75

Some physical methods of microbial control that work by removing microbes are just as effective as agents that kill or inhibit these microbes. Explain why this is so, and give some examples of these types of agents.