Chapter 11 Practice Exercises Flashcards
Sanitization is a process by which
Multiple Choice
A) objects are made sterile with chemicals.
B) the microbial load on an object is reduced.
C) skin is debrided.
D) hands are scrubbed.
B) the microbial load on an object is reduced.
Select the major cellular targets of physical and chemical control agents.
Check All That Apply
A) Cell wall
B) Flagella
C) Cell membrane
D) Proteins
E) Microcompartments
A) Cell wall
C) Cell membrane
D) Proteins
Explanation: There are four main targets of physical and chemical control agents. These include the cell wall, the cell membrane, cellular synthetic processes, and proteins.
Disinfection procedures must take into account
Multiple Choice
A) the mixture of microbes being targeted.
B) whether the microbes in biofilms are dispersed.
C) the amount of organic matter associated with the microbes.
D) All of these choices must be taken into account.
D) All of these choices must be taken into account.
Select the characteristics of a chemical control agent that make it a desirable agent.
Check All That Apply
A) Corrosive to metals and plastics
B) Water or alcohol soluble and stable
C) “-cidal” to a wide range of microbes, but nontoxic to humans and animal tissue
D) Rapidly effective in low concentrations
E) Ineffective in the presence of organic matter
F) Inexpensive
G) Short-lived, spontaneously inactivates with time
B) Water or alcohol soluble and stable
C) “-cidal” to a wide range of microbes, but nontoxic to humans and animal tissue
D) Rapidly effective in low concentrations
F) Inexpensive
Explanation: Some desirable characteristics that chemical control agents should possess include the following: They should be rapidly effective in low concentrations, -cidal to a wide range of microbes yet nontoxic to human and animal tissue, soluble in water or alcohol, inexpensive, noncorrosive to metals and plastics, demonstrate persistent or cumulative activity, and be stable and effective in the presence of organic matter.
Because prions are so resistant to typical control methods, it is not important to consider them when attempting to sterilize a substance or environment.
A) True
B) False
B) False
Explanation: Sterilization means void of all microbial life. Prions are merely infectious protein molecules, but they are important agents of disease that must be considered when sterilizing items such as surgical instruments.
Clostridioides difficile forms endospores. This characteristic makes this pathogen a concern for healthcare-associated infections.
A) True
B) False
A) True
Explanation: Endospores are highly resistant, making any organism that produces them highly resistant. This has made C. diff a major cause of HAIs (healthcare-association infections).
Order these types of microbes in terms of their resistance, from least resistance to most resistance.
A) Enveloped viruses, naked viruses, vegetative bacteria, protozoans, endospores, prions
B) Naked viruses, enveloped viruses, vegetative bacteria, protozoans, endospores, prions
C) Enveloped viruses, naked viruses, protozoans, vegetative bacteria, endospores, prions
D) Enveloped viruses, naked viruses, protozoans, prions, vegetative bacteria, endospores
A) Enveloped viruses, naked viruses, vegetative bacteria, protozoans, endospores, prions
Explanation: Review Figure 11.2 to help you determine the relative resistance of different microbial agents.
Which of these represents a chemical sterilant?
A) Chlorhexidine
B) Phenolics
C) Alcohols
D) Ethylene oxide
D) Ethylene oxide
Explanation: Ethylene oxide is a chemical sterilant. The others only affect some microbes and are not sporocidal.
Select all of the food items where microbial growth is controlled by means of osmotic pressure.
Check All That Apply
A) Honey
B) Apple cider
C) Salt-cured meats
D) Milk
E) Yogurt
F) Jellies
A) Honey
C) Salt-cured meats
F) Jellies
Explanation: Some foods are preserved by osmotic pressure. This is done by creating a hypertonic environment with salt or sugar that will cause bacteria to plasmolyze. Examples are honey, corn syrup, and jellies (high sugar) as well as salt-cured meats and fish (high salt).
Desiccation is a form of physical control of microorganisms that can be used in moist or dry forms.
A) True
B) False
B) False
Explanation: The six methods of physical control of microorganisms include heat (which can occur in moist or dry forms), cold, radiation, filtration, desiccation, and osmotic pressure. Desiccation refers to “drying” so there is definitely not a moist option!
Select the advantages of glutaraldehyde as an antimicrobial agent.
Check All That Apply
A) It can be used as an antiseptic as well as a disinfectant.
B) It remains effective in the presence of organic matter.
C) It is non-corrosive.
D) It is a chemical sterilant and high level disinfectant.
E) It is effective over a broad range of pH and temperatures.
B) It remains effective in the presence of organic matter.
C) It is non-corrosive.
D) It is a chemical sterilant and high level disinfectant.
Explanation: Glutaraldehyde is a broad-spectrum microbicide that is classified as a chemical sterilant and high level disinfectant. It maintains its activity in the presence of organic matter, is non-corrosive, and does not damage plastics. While less toxic than formaldehyde (another adehyde used for microbial control), it is not used as an antiseptic. The major disadvantage is its instability at increased pH and temperature.
The most versatile method for sterilizing heat-sensitive liquids is
Multiple Choice
A) peracetic acid.
B) exposure to ozone.
C) UV radiation.
D) filtration.
D) filtration.
Transcription is targeted most directly by
Multiple Choice
A) detergents.
B) quats.
C) alcohol.
D) UV radiation.
D) UV radiation.
Match the term to its description to test your understanding of the use of moist heat methods to control microbial growth.
1) Steam under pressure 2) Pasteurization
3) Boiling water
A) This method requires the use of an autoclave. To sterilize, temperature must reach 121°C for a minimum of 15 minutes.
B) Heat is applied to beverages to prevent spoilage and kill pathogens, but it does not sterilize. Protocols include holding liquids at 71.6°C for 15 seconds or at 63°C for 30 minutes.
C) This exposes a material to a temperature of 100°C. Thirty minutes of exposure will disinfect but will not sterilize.
1) Steam under pressure
A) This method requires the use of an autoclave. To sterilize, temperature must reach 121°C for a minimum of 15 minutes.
2) Pasteurization
B) Heat is applied to beverages to prevent spoilage and kill pathogens, but it does not sterilize. Protocols include holding liquids at 71.6°C for 15 seconds or at 63°C for 30 minutes.
3) Boiling water
C) This exposes a material to a temperature of 100°C. Thirty minutes of exposure will disinfect but will not sterilize.
Evaluate the statements below, and select those that correctly apply to the use of radiation as a microbial control mechanism.
Check All That Apply
A) The use of radiation to control microbial growth comes in two forms; ionizing and nonionizing radiation. Of the two, ionizing radiation is the most destructive.
B) Nonionizing radiation involves electrons being bombarded with enough energy to eject them from their atoms. Gamma rays are an example of this.
C) Nonionizing radiation, e.g., UV light, causes electrons to make a quantum leap to an orbital with a higher energy state, which causes thymine dimers to form, but does not create ions.
D) Ionizing radiation involves electrons being bombarded with enough energy to eject them from their atoms. X rays are an example of this.
E) The use of radiation to control microbial growth comes in two forms; ionizing and nonionizing radiation. Of the two, nonionizing radiation is the most destructive.
A) The use of radiation to control microbial growth comes in two forms; ionizing and nonionizing radiation. Of the two, ionizing radiation is the most destructive.
C) Nonionizing radiation, e.g., UV light, causes electrons to make a quantum leap to an orbital with a higher energy state, which causes thymine dimers to form, but does not create ions.
D) Ionizing radiation involves electrons being bombarded with enough energy to eject them from their atoms. X rays are an example of this.
What was the most likely mode of transmission of Cryptosporidium at the Seneca Lake State Park Sprayground?
A) Via a vector
B) Airborne
C) Water-borne
D) Food-borne
C) Water-borne
Explanation: The outbreak was most likely water-borne, where transmission of the pathogen to the children occurred through ingesting water from the spray fountains as they played.
Cryptosporidium was able to evade or resist filtration and chlorination of the spray park’s water supply.
A) True
B) False
A) True
Explanation: Cryptosporidium is resistant to chlorine and is small enough to pass through filters, and therefore was able to evade the spray park’s water treatment systems.
Ultraviolet water treatment systems are very common in _________ but not in the United States.
multiple choice
A) Australia
B) Asia
C) South America
D) Europe
D) Europe
Explanation: UV treatment systems were very common in Europe, but the system installed in the Seneca State Park was one of the first in the United States.
UV water treatment systems are effective in treating:
A) protozoans.
B) bacteria.
C) viruses.
D) All of these choices are correct.
D) All of these choices are correct.
Explanation: Because UV light damages DNA, all forms of water-borne microbes will be killed by this method.
UV irradiation inactivates Cryptosporidium because
A) it blocks the action of lysozyme.
B) it leads to a blocking of the action of DNA polymerase and RNA polymerase.
C) it removes thymine dimers within the DNA.
D) it denatures the proteins within the microorganism.
B) it leads to a blocking of the action of DNA polymerase and RNA polymerase.
Explanation: UV light induces thymine dimer formation in the DNA of this and other microorganisms, which effectively blocks the replication (by DNA polymerase) and transcription (by RNA polymerase) of the genetic material.
Using a bleach solution to clean the large metals carts in the operating room would have resulted in _________ of the carts.
A) antisepsis
B) degermation
C) sterilization
D) disinfection
D) disinfection
Explanation: Bleach is a chlorine compound that will destroy many microbes on the surface of these carts (inanimate objects), but will not result in sterility. Therefore, this is an example of disinfection.
Scrubbing the hands with water and using an alcohol-based hand cleaner is an example of:
A) degermation.
B) disinfection.
C) sterilization.
D) antisepsis.
D) antisepsis.
Explanation: Using chemicals and mechanical scrubbing on body tissues to remove and destroy microbes is referred to as antisepsis.
Which of the following methods could have been used for sterilizing the surgical equipment used in this kidney transplant?
Select all that apply.
A) Ethylene oxide
B) Chlorhexidine
C) Detergents
D) Autoclave
E) 35% hydrogen peroxide in chamber
A) Ethylene oxide
D) Autoclave
E) 35% hydrogen peroxide in chamber
Explanation: Ethylene oxide or 35% hydrogen peroxide can be used in chambers for sterilization of medical equipment. The autoclave is a physical method that can also sterilize heat-resistant materials.
The sponge used to scrub the surgical site was likely soaked in a/an
A) 35% hydrogen preoxide.
B) liquid chlorine.
C) 2-10% iodophor.
D) phenol.
C) 2-10% iodophor.
Explanation: Iodophors (2 —10%) are commonly used in surgical skin preparations.
After surgery, what methods could have been used to safely dispose of biohazard waste?
Select all that apply.
A) Incinerator
B) Detergents
C) Iodophors
D) Autoclave
E) Chlorhexidine
A) Incinerator
D) Autoclave
Explanation: Biohazard waste can be disposed of after autoclaving or by using a large incinerator.
The word thermal indicates the use of heat. In general, _________ temperatures require _________ exposure times.
A) higher; shorter
B) higher; longer
A) higher; shorter
Explanation: Higher temperatures usually require shorter exposure times.
The factors that must be considered when attempting to use heat for sterilization include which two of the following?
Select all that apply
A) Temperature
B) Concentration
C) Time
D) Population
A) Temperature
C) Time
Explanation: Exposure time and temperature must be considered for sterilization.
If we can kill all microbes in a substance in five minutes at 150 °C, that is the best temperature to use for sterilization.
A) True
B) False
B) False
Explanation: The foods may be affected by the high temperature. It might be better to use a lower temperature for a longer period of time.
What is the best measurement to consider when dealing with heat-sensitive materials?
A) Thermal death point
B) Thermal death time
B) Thermal death time
Explanation: The thermal death time is important to consider. If you know the highest temperature that a food can withstand and not be affected, you could just determine the minimum time at that temperature for sterilization.
Campylobacter jejuni, the organism implicated in this reported outbreak, is a/an:
A) yeast.
B) algae.
C) protozoan.
D) virus.
E) bacterium.
E) bacterium.
Campylobacter is a/an _________ organism, meaning that it has complex nutritional requirements and can be difficult to grow using general growth media.
A) ubiquitous
B) endogenous
C) fastidious
D) coliform
C) fastidious
What body system is usually affected by Campylobacter?
A) Gastrointestinal
B) Urogenital
C) Cardiovascular
D) Respiratory
A) Gastrointestinal
If routine testing would have been conducted on the milk from dairy A, this outbreak could have easily been prevented.
A) True
B) False
B) False
What is pasteurization?
A) The application of pressure as a microbicidal agent to pathogens in liquids
B) The use of moist heat to reduce the number of pathogens in liquids
C) The use of dry heat to remove dangerous microbes from beverages
D) The sterilization of milk, juices, and cheeses
B) The use of moist heat to reduce the number of pathogens in liquids
Choose the microbial control method that neither inhibits nor kills microbes, but instead physically removes them from liquids or air.
A) Lyophilization
B) Filtration
C) Irradiation
D) Cold sterilization
E) Desiccation
B) Filtration
Explanation: Filtration is able to physically remove microbes from liquids and from air. There are filters with pores tiny enough to prevent the passage of viruses and thus are able to sterilize solutions or air that is passed through them.
What represents a nonionizing form of radiation, often used for disinfection purposes?
A) X rays
B) UV radiation
C) Gamma rays
D) Cathode rays
B) UV radiation
Explanation: Ionizing radiation such as gamma radiation is used for cold sterilization of a variety of items, including plastics, pharmaceuticals, and foods. Nonionizing radiation, also known as UV light, doesn’t penetrate well, but can readily be used for disinfection purposes.
True or False: Moist heat methods operate at higher temperatures and longer exposure times as compared to dry heat methods.
A) True
B) False
B) False
Explanation: This is false. Moist heat methods are effective at lower temperatures and shorter exposure times when compared to dry heat methods.
Which of the following represents one of the four major targets of antimicrobial agents?
A) Lysosomes
B) Capsules
C) Cell wall
D) Flagella
C) Cell wall
Explanation: There are four main targets of physical and chemical control agents. These include the cell wall, the cell membrane, cellular synthetic processes, and proteins.
Evaluate the statements below, and select those that correctly apply to the use of radiation as a microbial control mechanism.
Check All That Apply
A) The use of radiation to control microbial growth comes in two forms; ionizing and nonionizing radiation. Of the two, ionizing radiation is the most destructive.
B) Nonionizing radiation involves electrons being bombarded with enough energy to eject them from their atoms. Gamma rays are an example of this.
C) Nonionizing radiation, e.g., UV light, causes electrons to make a quantum leap to an orbital with a higher energy state, which causes thymine dimers to form, but does not create ions.
D) Ionizing radiation involves electrons being bombarded with enough energy to eject them from their atoms. X rays are an example of this.
E) The use of radiation to control microbial growth comes in two forms; ionizing and nonionizing radiation. Of the two, nonionizing radiation is the most destructive.
A) The use of radiation to control microbial growth comes in two forms; ionizing and nonionizing radiation. Of the two, ionizing radiation is the most destructive.
C) Nonionizing radiation, e.g., UV light, causes electrons to make a quantum leap to an orbital with a higher energy state, which causes thymine dimers to form, but does not create ions.
D) Ionizing radiation involves electrons being bombarded with enough energy to eject them from their atoms. X rays are an example of this.
A drug destroys the peptidoglycan molecules of a bacterial cell. Which of the four main targets is affected in this scenario?
A) Proteins
B) Cell membrane
C) Cell wall
D) Cellular synthesis
C) Cell wall
Select all of the agents that will kill a microbial pathogen or completely inactivate its ability to cause disease.
Check All That Apply
A) Bacteristat
B) Fungistat
C) Virucide
D) Germicide
E) Sporicide
C) Virucide
D) Germicide
E) Sporicide
Explanation: Any agent labeled “–cidal” will kill the target organism. A bactericidal chemical will kill bacteria. A chemical labeled as bacteriostatic will not kill, but will inhibit the growth of the bacteria. The root “–static” means to stop or inhibit.
True or False: A chemical labeled as bactericidal will kill bacteria whereas a chemical labeled as bacteriostatic will inhibit bacterial growth but will not kill them.
A) True
B) False
A) True
Explanation: Any agent labeled “–cidal” will kill the target organism. A bactericidal chemical will kill bacteria. A chemical labeled as bacteriostatic will not kill, but will inhibit the growth of the bacteria. The root “–static” means to stop or inhibit.
A/An _________ agent would be used to destroy bacteria on a countertop whereas a/an _________ agent would be used on skin prior to making an incision.
A) antiseptic; sterilant
B) disinfectant; antiseptic
C) antiseptic; disinfectant
D) disinfectant; sterilant
B) disinfectant; antiseptic
Match the term with its description to test your understanding of microbial control terminology.
1) Sterilization
2) Disinfection
3) Antisepsis
4) Decontamination
A) Destruction of all microbial life
B) Destruction of most microbial life on inanimate surfaces
C) Destruction of most microbial life on living tissue
D) Mechanical removal of most microbes from living or inanimate surfaces
1) Sterilization
A) Destruction of all microbial life
2) Disinfection
B) Destruction of most microbial life on inanimate surfaces
3) Antisepsis
C) Destruction of most microbial life on living tissue
4) Decontamination
D) Mechanical removal of most microbes from living or inanimate surfaces
