Deck 9: Controlling Microbial Growth in the Environment

Question 1

is the physical removal of microbes.

A) Sanitization
B) Antisepsis
C) Degerming
D) Disinfection
E) Sterilization

Answer 1

C

Question 2

Which of the following describes flash pasteurization?

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

Answer 2

C

Question 3

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

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

Answer 3

D

Question 4

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

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

Question 5

Silvadene, a topical treatment for burns, contains 1% silver. What category of chemical control agent is in Silvadene?

A) heavy metals
B) halogens
C) surfactants
D) oxidizing agents
E) aldehydes

Question 6

Boiling water for 10 minutes is effective in ridding it of

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

Question 7

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

Question 8

Which of the following statements about aldehydes is FALSE?

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

Question 9

Disinfecting agents naturally produced by microorganisms are

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

Question 10

Which of the following is bacteriostatic?

A) heating in an oven at 171°C for an hour
B) autoclaving
C) filtration
D) freezing below 0°C
E) flash Pasteurization

Question 11

Which of the following is a sterilizing agent?

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

Question 12

The use of lysozyme during the preparation of cheeses and wines is effective in reducing the numbers of

A) fungi.
B) prions.
C) all microbes.
D) viruses.
E) bacteria.

Question 13

Which of the following is a target of pasteurization?

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

Question 14

Which of the following infectious agents is least resistant to destruction by chemical methods?

A) bacterial endospores
B) fungal spores
C) vegetative bacterial cells
D) nonenveloped viruses
E) enveloped viruses

Question 15

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

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

Question 16

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

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

Question 17

Aseptic means

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

Question 18

Disinfectants that damage membranes include

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

Question 19

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) thermal death point
D) in- use test
E) phenol coefficient

Question 20

Antimicrobial agents that damage nucleic acids also affect

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

Question 21

Glutaraldehyde is used for

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

Question 22

The compound ethylene oxide is used in

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

Question 23

The chemical agents known as "quats" are used for

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

Question 24

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

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

Question 25

Alcohols are used for

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

Question 26

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

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

Question 27

Hydrogen peroxide is a(n)

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

Question 28

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

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

Question 29

The dairy creamer used in restaurants is usually treated by

A) ionizing radiation.
B) filtration.
C) lyophilization.
D) ultra- high- temperature pasteurization.
E) autoclaving.

Question 30

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

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

Question 31

Seventy percent alcohol is effective against

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

Question 32

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

Question 33

The process of incineration is used for

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

Question 34

The process of filtration is a(n)

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

Question 35

Which of the following is the most difficult to inactivate?

A) nonenveloped viruses
B) bacterial endospores
C) fungus spores
D) enveloped viruses
E) protozoal cysts

Question 36

Which of the following is an example of sanitization?

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

Question 37

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

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

Question 38

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

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

Question 39

Which of the following can be used to disinfect air?

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

Question 40

may be achieved using chlorine dioxide.

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

Question 41

Gamma irradiation is a process for

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

Question 42

The process of heating milk or fruit juice to levels that kill any pathogenic microbes present is known as (pasteurization/sanitization/lyophilization).

Question 43

The process of freeze- drying microbes to preserve them is (lyophilization/dessication).

Question 44

The antimicrobial chemical pictured above is a(n) (phenolic/surfactant/enzyme) compound found in many consumer products.

Question 45

Elements such as iodine, chlorine, and bromine are examples of (oxidizers/halogens/metals), which are the basis for many effective antimicrobial agents.

Question 46

Disinfectants known as (alcohols/oxidizers/aldehydes) have the chemical group - CHO, which reacts with and damages both proteins and nucleic acids.

Question 47

Heavy metal and oxidizing agent disinfectants damage (proteins/DNA/membranes), interfering with microbial metabolism.

Question 48

Microbial growth in jellies is inhibited by the (acidic/hypotonic/hypertonic) condition of the food.

Question 49

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

Question 50

The amount of time needed to sterilize materials using moist heat is (more/less) than the time needed to sterilize using dry heat.

Question 51

The deadliest, most contagious microbes are studied under conditions of (BSL- 4/BSL- 3/BSL- 2/BSL- 1) containment.

Question 52

A stationary broth culture contains 10 billion (1010) cells. The microbial death rate during autoclaving of this spent culture is 1.5 minutes. How long must it be autoclaved to be considered sterile?

A) 16.5 minutes
B) 10 minutes
C) 20 minutes
D) 12 minutes
E) 9 minutes

Question 53

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

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

Question 54

Ultraviolet light penetrates (more/less) effectively than gamma rays.

Question 55

Natural antiseptics such as pine or clove oil are examples of antimicrobial compounds called (alcohols/phenolics/detergents).

Question 56

Which of the following statements is TRUE of disinfectants?

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

Question 57

The (endospores/cysts/prions) are the infectious agents most resistant to antimicrobial agents or processes.

Question 58

The lowest temperature that kills all cells in a broth in 10 minutes is known as the (microbial/thermal) death point.

Question 59

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

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

Question 60

The effectiveness of sterilization procedures is evaluated using (prions/cysts/endospores) because of their resilience.

Question 61

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

Question 62

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

Question 63

Refrigeration is an effective germicidal method.

Question 64

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

Question 65

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 66

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

Question 67

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

Question 68

No chemical or antimicrobial agents inactivate prions.

Question 69

The pH conditions under which a chemical disinfectant is used do not alter its efficacy.

Question 70

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

Question 71

Removal of microbes from the skin is antisepsis.

Question 72

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

Question 73

Design an experiment to compare the effectiveness of a physical and a chemical method of disinfection.

Question 74

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

Question 75

Compare and contrast the nine major types of antimicrobial chemicals in terms of their effective on microbes.