Chpt 9 control of growth q & a

Alcohol is most effective when used as a ________ solution. A. 95% B. 100% C. 60% D. 70% E. 25%

70%

Which concentration of ethanol is the most effective bactericide? A. 100% B. 70% C. 50% D. 40% E. 30%

70%

A nurse is degerming a patient's arm before giving a vaccination. Which of these concentrations of alcohol is most effective? A. 100% B. 75% C. 50% D. 25%

75% Alcohols work by denaturing proteins, and this process requires water. Generally, the most effective alcohol concentration is 70%.

The decimal reduction time is the time required to kill __________ percent of a bacterial population

90%

By definition, a tincture contains alcohol. Why would a tincture of an antiseptic be more effective than an aqueous solution? A. Alcohol contributes to the effectiveness of an antiseptic because it denatures proteins. B. Alcohol contributes to the effectiveness of an antiseptic because it dissolves lipids. C. Answers A and B are both correct. D. Neither answer A nor B is correct

Answers A and B are both correct

Treatment is directed at living tissue A. sterilization B. Antisepsis C. Disinfection D. Degerming E. Sanitization

Antisepsis

Kills microorganisms A. Biocides B. fungicides C. virucide D. bacteriostasis E. spesis

Biocides

The mechanical removal of most microbes in an area A. sterilization B. Antisepsis C. Disinfection D. Degerming E. Sanitization

Degerming

When skin is cleaned with alcohol prior to an injection A. sterilization B. Antisepsis C. Disinfection D. Degerming E. Sanitization

Degerming

The destruction of vegetative pathogens that do not form endospores A. sterilization B. Antisepsis C. Disinfection D. Degerming E. Sanitization

Disinfection

Some microbes are very resistant to antimicrobial chemicals. Which of the following would be the easiest to kill? A. Mycobacterium tuberculosis B. E. coli. C. cysts of protozoa D. Pseudomonas aeruginosa E. Clostridium endospores

E. coli

True/ False Microorganisms placed in high concentrations of salts and sugars undergo lysis.

False

True/ False The pH of the medium has no effect on the activity of the disinfectant being applied.

False

True/False All bacteria die at once when they are exposed to heat or chemical treatment

False

True/False Iodine is one of the least effective antimicrobial chemicals, effective only against certain very sensitive strains of bacteria.

False

True/False Most viruses are highly resistant to disinfectants and antiseptics

False

True/False Soap is ineffective in killing bacteria. Therefore, hand washing is a rather ineffective measure in preventing disease transmission.

False

True/False UV radiation and x-ray radiation are similar in that they damage DNA and have a high penetrating power

False

Why would filter sterilization be used rather than heat, such as autoclaving? A. Filter sterilization is less expensive than autoclaving. B. Filter sterilization is used when the contents of the liquid could be harmed by heat. C. Filter sterilization is more effective than autoclaving

Filter sterilization is used when the contents of the liquid could be harmed by heat

__________ bacteria may survive pasteurization

Heat resistant

60 minutes

In the figure, what is the thermal death time? A. 150°C B. 120 minutes C. 100°C D. 60 minutes E. The answer cannot be determined.

Which of the following is a limitation of the autoclave? A. It requires an excessively long time to achieve sterilization. B. It cannot be used with glassware. C. It cannot inactivate viruses. D. It cannot be used with heat-labile materials. E. It cannot kill endospores

It cannot be used with heat-labile materials

_______________ is a process used to destroy pathogens in food and drinks. It must be done at a lower temperature than other methods so that _______________. A. autoclaving; beneficial microorganisms are not killed B. Pasteurization; beneficial microorganisms are not killed C. autoclaving; the taste of the food or drink will not be altered D. Pasteurization; the taste of the food or drink will not be altered

Pasteurization; the taste of the food or drink will not be altered

You are preparing a medium for growing fastidious bacteria and must add several heat-labile solutions of growth factors. Which of the following is an appropriate strategy for preparing and sterilizing this medium? A. Prepare and autoclave the medium before adding the growth factors. After the medium has cooled, filter sterilize and aseptically add the growth factors. B. Use UV radiation to sterilize this medium. C. Use dry heat to sterilize the medium. D. Prepare the medium, add the growth factors, and autoclave. E. Pasteurize the medium.

Prepare and autoclave the medium before adding the growth factors. After the medium has cooled, filter sterilize and aseptically add the growth factors.

__________ ammonium compounds are less effective against gram-negative bacteria and more effective against gram-positive bacteria.

Quaternary

Treatment intended to lower microbial counts on eatting and drinking utensils to safe public health levels A. sterilization B. Antisepsis C. Disinfection D. Degerming E. Sanitization

Sanitization

When a restaurant washes its dishes in a high-temp dishwasher A. sterilization B. Antisepsis C. Disinfection D. Degerming E. Sanitization

Sanitization

A nurse is working in southeast Asia, where the incidence of Mycobacterium tuberculosis is very high. Why is it necessary to select a specific method of disinfection for this organism ? A. The presence of a capsule makes this organism more resistant to disinfectants. B. Bacterial endospores made by this organism are resistant to disinfectants. C. The presence of an envelope makes this organism relatively resistant to disinfectants. D. The waxy, lipid-rich components of the cell wall make this organism relatively resistant to disinfectants.

The waxy, lipid-rich components of the cell wall make this organism relatively resistant to disinfectants

________ is a compound found in antimicrobial soaps that targets gram-positive bacteria. A. Sodium nitrate B. Mercuric chloride C. Formaldehyde D. Triclosan E. Hydrogen peroxide

Triclosan

True/ False Heating is the most common use for killing microbes

True

True/ False Pseudomonas has been found growing in quaternary ammonium compounds (quats).

True

True/False Ethylene oxide gas is used to sterilize medical equipment that might be damaged by exposure to the heat of autoclaving

True

True/False Ionizing radiation can be used to sterilize some foods such as spices, meat, and fruits and vegetables.

True

True/False The presence of organic matter, such as blood or saliva, may impair the action of antimicrobial chemicals

True

True/False Times required for sterilization in an autoclave are shorter than those required in a dry oven because moist heat penetrates biological specimens more effectively than does dry heat.

True

While waiting for your meal at a restaurant, you read the information on the creamer containers at your table and notice that they do not need to be refrigerated. You are surprised, because dairy products typically must be kept cold to prevent spoilage. How were these products treated to eliminate microbial growth and prevent spoilage? A. UHT treatment B. chemical preservatives C. gamma irradiation D. pasteurization

UHT treatment Ultra-high-temperature (UHT) is a treatment that essentially sterilizes the product

Which of the following shows the moist heat methods in order of the temperature used (highest to lowest)? A. Ultrahigh>Boiling>Autoclave>Batch Pasteurization B. Ultrahigh>Autoclave>Boiling>Batch Pasteurization C. Autoclave>Ultrahigh>Batch Pasteurization>Boiling D. Ultrahigh> Boiling>Batch Pasteurization >Autoclave

Ultrahigh>Autoclave>Boiling>Batch Pasteurization

Which of the following pairs is mismatched? A. organic acids food preservation B. H2O2 open wounds C. alcohols open wounds D. Ag wound dressings E. CuSO4 algicide

alcohols open wounds

Oxidizing agents, such as hydrogen peroxide, are useful for irrigating deep wounds where released oxygen will inhibit the growth of __________.

anaerobic bacteria

The chemical disinfection of living tissue is known as A) antisepsis B) degerming

antisepsis Antisepsis is the chemical disinfection of living tissues

Which method achieves sterilization? A) pasteurization B) the autoclave

autoclave The autoclave uses heat under pressure to allow temperatures above the boiling point of water to be reached.

Which of the following treatments achieves sterilization? A. pasteurization B. freezing C. bringing water to a boil D. autoclaving

autoclaving Autoclaving destroys all living organisms, spores, and endospores, thereby sterilizing heat-stable items

Some antimicrobial treatments kill microbes; some inhibit growth. Which term refers to an agent that inhibits bacterial growth? A. germicidal B. bacteriostatic C. homeostatic D. fungicidal E. bacteriocidal

bacteriostatic

Which of the following pairs of terms is mismatched? A. virucide - inactivates viruses B. fungicide kills yeasts and molds C. sterilant destroys all living microorganisms D. bacteriostatic kills vegetative bacterial cells E. germicide - kills microbes

bacteriostatic kills vegetative bacterial cells

All of the following are examples of microbial control using heavy metals except ________. A. mouthwash solution containing zinc chloride. B. burn treatment using silver-sulfadiazine ointment C. algae control in swimming pools using copper sulfate D. benzoyl peroxide used for acne treatment E. antiseptic solution containing mercurochrome

benzoyl peroxide used for acne treatment

What group of chemicals does triclosan fall into? A) a halogen B) a bisphenol

bisphenol Triclosan is a bisphenol found in many antimicrobial products, including antibacterial soaps

Which of the following disinfectants acts by disrupting the plasma membrane? A. heavy metals B. halogens C. bisphenols D. soaps E. aldehydes

bisphenols

__________ is a common household disinfectant that has been used to disinfectant everything from dairies to drinking water.

bleach

How does alcohol kill bacteria? A) by denaturing proteins B) by inhibiting DNA synthesis

by denaturing proteins

Which one of the following substances is effective against bacterial endospores? A. bisphenols B. quaternary compounds C. mercury D. chlorine

chlorine

Which one of these halogen compounds would be considered an antiseptic? A. hypochlorous acid B. calcium hypochlorite C. chlorine dioxide D. chlorine gas

chlorine dioxide

Application of heat to living cells can result in all of the following EXCEPT A. alteration of membrane permeability. B. denaturation of enzymes. C. decreased thermal death time. D. damage to nucleic acids. E. breaking of hydrogen bonds

decreased thermal death time

What is removal of microbes from skin by mechanical cleansing or by an antiseptic called? A) sanitization B) degerming

degerming Degerming removes microbes from the skin, such as when an alcohol swab is used prior to an injection.

Moist heat kills microbes by __________ of cellular components

denaturation

The preservation of beef jerky from microbial growth relies on which method of microbial control? A. filtration B. lyophilization C. desiccation D. supercritical CO2 E. ionizing radiation

desiccation

Sterilization is the ________. A. destruction of all life-forms B. destruction of all forms of microbial life except endospores C. effective removal of all microbes on a surface D. control of all microbial growth E. same as sanitization

destruction of all life-forms

All of the following methods are used for food preservation except ________. A. dessication B. osmotic pressure C. direct flaming D. deep freezing E. commercial canning

direct flaming

What is the best definition of sterilization? A. removal of unwanted microorganisms B. removal of viruses C. elimination of bacteria D. elimination of all microorganisms

elimination of all microorganisms

Which of the following chemical agents is used for sterilization? A. phenolics B. ethylene oxide C. alcohol D. soap E. chlorine

ethylene oxide

Which one of these chemical treatments kills cells by causing cross-linking of nucleic acids and proteins and inhibits vital cellular functions? A. alcohol B. ethylene oxide C. heavy metals D. soaps and detergents

ethylene oxide

True/False Household bleach contains chlorhexidine as the active ingredient

false

Which of the following is not a major target for action of antimicrobials? A. proteins B. nucleic acids C. enzymes D. cell membranes E. flagella

flagella

A chemical that reduces spoilage in fruit by destroying fungi, but does not appear to affect other microbes, would be called a __________. A. fungicidal agent B. fungistatic agent C. sterilant D. bactericidal agent

fungicidal agent

Which one of these products is most useful for disinfecting medical instruments? A. iodine B. glutaraldehyde C. alcohols D. soap and detergents

glutaraldehyde

To which category do iodine and chlorine belong? A) biguanide B) halogen

halogen

Which of the following results in lethal damage to nucleic acids? A. heat B. radiation C. certain chemicals D. heat and radiation E. heat, radiation, and some chemicals

heat, radiation, and some chemicals

Which one of the following physical methods of microbial control is bactericidal? A. refrigeration B. deep-freezing C. desiccation D. incineration

incineration

When iodine is combined with an organic molecule, it is called A) an iodophor B) tincture

iodophor When iodine is combined with an organic molecule, it is called an iodophor.

Which of the following is the best method to sterilize heat-labile solutions? A. dry heat B. autoclave C. pasteurization D. freezing E. membrane filtration

membrane filtration

What is the typical mechanism of action for chemical food preservatives? A. oxidation B. surface-active agents for removal of microbes C. metabolic inhibition D. disruption of plasma membranes

metabolic inhibition

Which type of radiation is least effective in killing microbes? A. gamma rays B. microwaves C. x-rays D. high-energy electron beams E. ultraviolet rays

microwaves

Which of the following are NOT typically destroyed by antimicrobial agents? A. nuclei B. proteins C. nucleic acids D. plasma membranes

nuclei Bacteria do not contain nuclei, and since most disinfectants target bacteria, nuclei are not a typical target

Recently, silver has been considered in new applications for microbial control, such as impregnating surgical dressings and infusing food containers with silver. These new applications are important because silver is__________. A. useful as a surface-active agent B. effective in dissolving lipids in the plasma membrane C. oligodynamic and unaffected by antimicrobial resistance D. effective as an oxidizing agent

oligodynamic and unaffected by antimicrobial resistance

Which method of control is it when we use concentrated salt solutions to cure meats? A) osmotic pressure B) high pressure

osmotic pressure

Which of the following does not kill endospores? A) autoclaving B) pasteurization

pasteurization Pasteurization does not kill endospores

Which of the following infectious agents challenges current sterilization strategies that have been accepted and in use for decades? A. endospores B. mycobacteria C. HIV D. methicillin-resistant Staphylococcus aureus (MRSA) E. prions

prions

Which of the following is least likely to be damaged by exposure to gamma radiation? A. protozoa B. prions C. bacteria D. fungi E. viruses

prions

Disinfection methods have NOT completely solved the problem of destroying which of the following? A. prions B. endospores C. protozoan cysts D. enveloped viruses

prions Prions are especially difficult to destroy. Incineration has been used for infected organisms. but effective treatment for equipment is still being determined. Even autoclaving requires the addition of sodium hydroxide.

Which of these microbes is the most difficult to destroy using either chemical or physical methods? A. prions B. HIV C. MRSA (methicillin-resistant Staphylococcus aureus) D. bacterial endospores

prions Prions are the most difficult infectious particles to destroy. Currently, a combination of very high temperature and sodium hydroxide is used

Which of the following correctly describes antisepsis? A. destruction of vegetative microorganisms on inanimate surfaces B. removal of vegetative microorganisms from living tissue C. reduction of microbial cells on eating or drinking utensils D. destruction of all organisms on any surface

removal of vegetative microorganisms from living tissue

Which type of treatment is it when a restaurant washes its eating utensils? A) sanitization B) degerming

sanitization Sanitization lowers the microbial count to safe public health levels

An antiseptic is used to remove microbes from ________. A. restaurant glassware B. food preparation areas C. toilet surfaces D. skin, before an injection E. foods, before canning them

skin, before an injection

What is the main effect of refrigeration on microbes? A) kills microbes B) slows microbial growth

slows microbial growth

Food is subjected to enough heat to destroy the endospores A. sterilization B. Antisepsis C. Disinfection D. Degerming E. Sanitization

sterilization

The destruction or removal of all forms of life A. sterilization B. Antisepsis C. Disinfection D. Degerming E. Sanitization

sterilization

Usually done by steam under pressure or ethylene oxide A. sterilization B. Antisepsis C. Disinfection D. Degerming E. Sanitization

sterilization

Destroying all forms of microbial life is known as A) disinfection B) sterilization

sterilization Sterilization is the destruction of all forms of microbial life

What would be an appropriate use of ultra-high-temperature treatment? A) sterilizing rubber tubing B) sterilizing coffee creamers.

sterilizing coffee creamers

What does UV radiation damage in a cell? A) proteins B) the DNA

the DNA

Pasteurized milk in an unopened container spoils in the refrigerator. A sample reveals the presence of microorganisms. The most likely explanation is ________. A. the microbes that survived pasteurization were able to grow at 4°C. B. the microbes are pathogens C. the pasteurization process was ineffective D. a leak in the milk carton allowed microbes to enter E. pasteurization-resistant mutants developed after pasteurization

the microbes that survived pasteurization were able to grow at 4°C.

Which of these is not a characteristic of the autoclave? A. the use of moist heat B. the requirement for long (hours) exposure times C. the ability to sterilize solutions with endospores D. the use of high temperatures E. the use of high pressures

the requirement for long (hours) exposure times

For which of the following would it be appropriate to use high-energy electron beams as a means to control microbial growth? A) to sterilize disposable dental supplies B) to disinfect the air going into a nursery

to sterilize disposable dental supplies

Which of these chemicals inhibits an enzyme required for synthesis of membrane lipids? A. chlorine B. hydrogen peroxide C. ozone D. triclosan

triclosan

True/False The most commonly used iodophor is Betadine

true

Packages of milk and coffee creamers may be stored without refrigeration if they have been sterilized by ________. A. boiling B. ultra-high-temperature (UHT) treatment C. autoclaving D. treatment with phenol E. high-temperature short-time (HTST) pasteurization

ultra-high-temperature (UHT) treatment

For control of microbial growth on a surface, which of these conditions is LEAST likely to interfere with the effectiveness of an antiseptic or disinfectant? A. presence of organic matter B. high numbers of microbes C. presence of biofilms D. warm environmental conditions

warm environmental conditions

When would it be appropriate to use glutaraldehyde? A) when embalming corpses B) when disinfecting water for swimming pools

when embalming corpses

Pasteurization was first used by Pasteur to control spoilage of ________. A. milk B. yogurt C. wine D. cheese E. canned foods

wine

The following may be listed on the ingredients of your favorite snack food. Which of these products is not antimicrobial? A. sodium benzoate B. sorbic acid C. xanthan D. potassium sorbate E. calcium propionate

xanthan

During a flood, a community's well water system is contaminated with a pathogenic fungus. If the residents boil their water for 15 minutes prior to consumption, will they be protected? A. yes, most likely B. probably not C. definitely not

yes, most likely