Chapter 11 Microbiology 2*

The minimum sterilizing conditions in a steam autoclave are: A) 121 C at 15 psi for 15 minutes B) 63 C for 30 minutes C) 160 C for 2 hours D) 71.6 C for 15 seconds E) 100 C for 30 minutes

121 C at 15 psi for 15 minutes

A chemical that slows bacterial growth is said to be _________________? a) bacteriostatic b) fungistatic c) bactericidal d) microbiostatic e) allosteric

A

Agents that alter protein function may do all but which of the following? a) prevent peptide bond formation. b) Denature proteins. c) Coagulate proteins. d) Alter an enzyme's active site. e) Prevent an enzyme from interacting with the substrate.

A

Both ionizing and nonionizing radiation tend to effect what? a) DNA b) RNA c) Cell membrane d) Cell wall e) Proteins

A

Choose the best method for the sterilization of an enzyme solution: a) filtration b) dry heat c) autoclave d) freezing e) pasteurization

A

Common methods of using moist heat to control microbial growth include all but which of the following? a) Incineration. b) steam under pressure. c) live, unpressurized steam. d) Boiling water. e) Pasteurization.

A

Fluorine, bromine, chlorine and iodine are classified as nonmetallic: a) halogens b) phenolics c) alcohols d) detergents e) peroxides

A

Pasteurization is a technique in which heat is applied to liquids to kill potential agents of infection and spoilage, while at the same time retaining the liquid's flavor and food value. a) True or b) False

A

Which of the following is mismatched? a) UHT Pasteurization - 180°C. b) HT Pasteurization - 72°C . c) Incineration - 1100°C or more. d) Microwave - 100°C. e) Intermittant Dry Heat in an oven - 150 to 180°C.

A

All of the following are examples of microbial control using heavy metals except: a) mouthwash solution containing zinc chloride. b) benzoyl peroxide used for acne treatment. c) burn treatment using silver-sulfadiazine ointment. d) algae control in swimming pools using copper sulfate. e) antiseptic solution containing mecurochrome.

B

Any process that destroys the non-spore-forming contaminants on inanimate objects is: a) antisepsis b) disinfection c) sterilization d) degermination e) chemotherapy

B

Boiling an object for a few minutes will make it slightly sterile. a) True or b) False

B

Chilling, freezing and desiccation are: a) microbiocidal b) microbiostatic c) disinfectants d) sterilants e) effective against endospores

B

Detergents and soaps are: a) High level germicides b) Low level germicides c) Excellent antiseptics. d) Used in disinfecting surgical instruments. e) Totally useless against microbes.

B

Higher temperatures (100°C) _____________ and low temperatures (4°C) _____________: a) Decrease effectiveness of disinfectants, increase metabolism. b) Kill cells, inhibit cell growth. c) Burst cells, denature proteins. d) Speed up metabolism, slow down metabolism. e) Decrease metabolism, increase the effectiveness of disinfectants.

B

Inoculating loops are generally sterilized using: a) moist heat b) incineration c) chemicals d) filtration e) autoclaving

B

Lyophilization preserves food and microbes through: a) Reducing the temperature. b) Freezing and dehydration. c) Dehydration. d) Pasteurization. e) Osmotic potential.

B

Microbial death is defined as which of the following? a) the permanent termination of an organism's vital processes. b) The permanent loss of reproductive capability, even under optimal growth conditions. c) The loss of movement in a motile microbe. d) Exposure to a chemical or physical agent for a period of time until a cell structure becomes dysfunctional. e) Irreversible damage to a cell.

B

Phenolics used for disinfection include all but which of the following? a) Phenol b) Chlorhexidine c) Lysol d) PhisoHex e) Triclosan

B

The cellular targets of physical and chemical agents fall into general categories including those that damage: a) the mitochondrion b) the cell membrane c) cytoplasmic inclusions d) the nucleus e) the endoplasmic reticulum

B

The following may be listed on the ingredients of your favorite snack food. Which of the following is not antimicrobial? a) calcium propionate. b) xanthan. c) potassium sorbate. d) sodium benxoate. e) sorbic acid.

B

The primary mode of action of nonionizing radiation is to: a) Produce superoxide ions. b) Make pyrimidine dimers. c) Denature proteins. d) Break disulfide bonds. e) Cause molecules to lose electrons and ionize.

B

The temperature-pressure combination for an autoclave is: a) 100 degrees C and 4 psi. b) 121 degrees C and 15 psi. c) 131 degrees C and 9 psi. d) 115 degrees C and 3 psi. e) 72 degrees C and 0 psi.

B

What is the most widely used of the physical methods of microbial control? a) filtration b) heat c) radiation d) cold e) ultrasonic waves

B

Iodophors include: A) chloramines B) Betadine C) tincture of iodine D) alcohols E) chlorhexidine

Betadine

Desirable qualities in a microbiocidal chemical include all but which of the following? a) Rapid action b) inexpensive c) inactivated by organic matter d) broad spectrum e) soluble in water or alcohol.

C

Exposure to cold temperatures has what effect on microorganisms? a) it removes moisture from the environment and thus prevents growth. b) It oxidizes and coagulates proteins. c) It retards the activities of most microbes. d) It denatures proteins. e) It kills endospores and thermophilic organisms.

C

The first disinfectant used by Lister was ___________________. a) listerine. b) betadine. c) phenol. d) chlorine. e) iodine.

C

Which of the following is not a concern that must be taken into consideration when selecting a method of microbial control? a) The method must be suitable for the application. b) The method should not leave an undesirable residue behind. c) The method should be effective regardless of cost and labor effectiveness. d) The method should destroy only the microbial forms present. e) If the disinfected item is to be reused, it should be able to withstand the antimicrobial treatment.

C

_____ is a halogen used in gaseous and liquid form for large scale disinfection of drinking water and sewage.

Chlorine

Which of the following is not a method of microbial control used in ancient times? A) Salting, smoking, pickling, and drying foods B) Exposing food, clothing, and bedding to sunlight C) Boiling drinking water D) Consuming molds to derive antibiotic benefits E) Burying human wastes

Consuming molds to derive antibiotic benefits

A chemical with sporicidal properties is: a) Phenol b) alcohol c) quaternary ammonium compound d) gluaraldehyde e) heavy metals such as silver.

D

An effective method of sterilizing heat-sensitive liquids is: a) UV radiation. b) Exposure to ozone. c) Autoclaving. d) Filtration. e) Gamma radiation.

D

Identify the form of nonionizing radiation from the list below: a) gamma rays b) x-rays c) cathode rays d) ultra violet rays e) plutonium

D

Overuse of germicides is leading to all but which of the following problems? a) Survival and growth advantages of resistant strains. b) Obsessive fear of "germs" among the general public. c) The selection of "supermicrobes". d) Increased sensitivity of microbes to the phenolic triclosan. e) A reduction in natural contact with microbes required for maintenance of normal flora and for stimulation of immunity.

D

Pasteurization rids liquids of what microbial form? a) Endospores. b) Thermotolerant organisms. c) Nonpathogenic lactobacilli. d) Most viruses and vegetative stages of 97-99% of bacteria and fungi. e) Non-pathogenic micrococci.

D

Physical and chemical antimicrobial agents can target all but which of the following? a) protein function. b) Cell membrane integrity. c) DNA replication. d) Capsule formation. e) Cell wall synthesis.

D

Sterilization by filtration removes microbes from heat-sensitive liquids and circulating air. The type of microbe removed depends on the: a) pH of the liquid. b) Temperature of the liquid. c) Temperature of the air. d) Pore size of the filter. e) Electrical charge of the filter.

D

What process mechanically removes microorganisms, reducing contamination to safe levels? a) Sterilization b) antiseptic use c) disinfection d) sanitization e) lyophilization

D

Which of the following does not affect the action of antimicrobial agents? a) Contact time & number of microbes present. b) Temperature & pH of the environment. c) Presence of organic matter. d) Motility of the pathogen. e) Expiration date of the agent.

D

Some microbial control agents are able to _____ cell proteins by breaking bonds that maintain the native state, three-dimensional configuration of the proteins.

Denature

Alcohol is most effective when used as a ___________ solution. a) 25% b) 60% c) 95% d) 100% e) 70%

E

For what method of microbial growth control is the application of UV light useful? a) Antisepsis b) Sterilization c) Bacteriostasis d) Sanitization e) Disinfection

E

Packages of milk and coffee creamers may be stored without refrigeration if they have been sterilized by: a) boiling. b) high temperature short-time (HTST) pasteurization. c) autoclaving. d) treatment with phenol. e) ultra-high-temperature (UHT) treatment.

E

Surfactants function as microbiocidal agents because they do what to microorganisms? a) Inhibit peptide bond formation during translation. b) Interfere with the synthesis of peptidoglycan. c) Prevent mRNA transcription. d) Denature proteins. e) Disrupt the integrity and lower the surface tension of cell membranes.

E

What germicidal chemical is used to prepare skin and mucous membranes for surgery and injections, is included in surgical handscrubs, is used to treat burns, and is used to disinfect equipment and surfaces? a) Ethylene oxide gas b) formaldehyde c) phenolics d) glutaraldehyde e) iodine/iodophores

E

What term is defined as a chemical agent that is applied directly to body surfaces, wounds & surgical incisions to destroy or inhibit vegetative pathogens? a) bacteriostatic agent b) fungicide c) disinfectant d) sanitizer e) antiseptic

E

_____________ is a compound found in antimicrobial soaps that targets gram-positive bacteria. a) sodium nitrate. b) mercuric chloride. c) hydrogen peroxide. d) formaldehyde. e) triclosan.

E

A microorganism that is not motile and has stopped metabolizing could be considered dead. A) True B) False

False

All microbicidal agents are sterilants. A) True B) False

False

Bacteriostatic agents kill bacterial cells. A) True B) False

False

Chlorine compounds remain stable and effective in the presence of excess organic matter. A) True B) False

False

Isopropyl alcohol wiped across a skin site can sterilize it. A) True B) False

False

Most microbial contaminants of food are killed at freezing temperatures. A) True B) False

False

_____ is a control method that removes microorganisms rather than inhibiting or killing them.

Filtration

Vials of microorganisms that undergo the freeze-drying process called _____ will remain preserved and viable for years.

Lyophilization

Which is mismatched: A) sodium hypochlorite - chlorine B) iodophor - iodine C) benzalkonium chloride - quaternary ammonium compound D) Merthiolate - silver E) formalin - formaldehyde

Merthiolate - silver

_____ heat is more rapidly effective and efficient compared to _____heat.

Moist, Dry

_____ radiation excites atoms to a higher energy state within molecules such as DNA that then leads to the formation of pyrimidine dimers.

Nonionizing

_____ solution was introduced in the late nineteenth century for preventing gonococcal infections in a newborn's eyes after exposure to the mother's infected birth canal.

Silver Nitrate

Alcohols are more effective at inactivating enveloped viruses than naked viruses. A) True B) False

True

Analine dyes like crystal violet have antimicrobial activity particularly against gram positive bacteria and some fungi. A) True B) False

True

Chlorine dioxide and ethylene oxide are sterilizing gases. A) True B) False

True

Sonication dislodges debris and saliva from instruments but will not reliably achieve disinfection or sterilization. A) True B) False

True

The presence of organic matter such as saliva and pus can interfere with the actions of disinfectants. A) True B) False

True

When a control agent targets the metabolic processes of microbial cells, active younger cells typically die more rapidly than older cells. A) True B) False

True

A method for sterilizing milk, called _____ temperature treatment, uses 134 C for 1 to 2 seconds.

Ultrahigh

HEPA filters are used to remove microbes from: A) air B) liquids C) human tissues D) medical instruments E) all of the choices are correct

air

Alcohols: A) denature proteins when in a 50 - 95% alcohol-water solution B) disinfect items soaked in alcohol C) are skin degerming agents D) at 50% or higher concentrations dissolve cell membrane lipids E) all of the choices are correct

all of the choices are correct

Endospores can be killed by: A) dry heat at 170 C for 2 hours B) incineration C) glutaldehyde for 3 or more hours D) ethylene oxide for 3 or more hours E) all of the choices are correct

all of the choices are correct

Which of the following items are typically irradiated in order to kill microbes? A) ground beef and other meat and poultry B) human tissues such as heart valves and skin C) operating room air D) surgical gloves E) all of the choices are correct

all of the choices are correct

The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is: A) disinfection B) sterilization C) antisepsis D) sanitization E) degermation

antisepsis

Which of the following is not used as an antiseptic? A) iodophor B) chlorhexidine C) 3% hydrogen peroxide D) Merthiolate E) aqueous glutaraldehyde

aqueous glutaraldehyde

What is the goal of sterilization? a) the destruction of protozoan trophozoites. b) the destruction of bacterial endospores. c) the destruction or inhibition of vegetative pathogens through chemicals applied to body surfaces. d) to temporarily inhibit the reproduction of microbes but not inflict irreversible damage. e) the destruction of fungal sexual spores (zygospores).

b

Of the microbial forms listed below, which exhibits the highest level of resistance to physical and chemical methods of growth control? a) Protozoan cysts b) most vegetative bacterial cells c) bacterial endospores d) naked viruses e) yeasts

c

All of the following are phenols or phenolics except: A) Lysol B) hexachlorophene C) triclosan D) cresols E) chloramines

chloramines

The compound that is an organic base containing chlorine and two phenolic rings, and is used increasingly for wound degerming, neonatal washs, handscrubbing, and prepping surgical skin sites is: A) carbolic acid B) chlorhexidine C) triclosan D) formalin E) quarternary ammonium compounds

chlorhexidine

Scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is: A) disinfection B) sterilization C) antisepsis D) sanitization E) degermation

degermation

The use of a physical or chemical process to destroy vegetative pathogens is: A) disinfection B) sterilization C) antisepsis D) sanitization E) degermation

disinfection

Dry heat: A) is less efficient than moist heat B) cannot sterilize C) includes tyndallization D) is used in devices called autoclaves E) will sterilize at 121 C for 15 minutes

dry heat at 170 C for 2 hours

The sterilizing gas used in chemiclaves is: A) ethylene oxide B) iodophor C) glutaraldehyde D) formaldehyde E) chlorine dioxide

ethylene oxide

All of the following pertain to hypochlorites except: A) release hypochlorous acid in solution B) cause denaturation of enzymes C) found in iodophors D) used to disinfect dairy, restaurant, and medical equipment E) found in common household bleach

found in iodophors

Electrons are ejected from atoms in cells when organisms are exposed to: A) dessication B) ultraviolet light C) ethyl alcohol D) hydrogen peroxide E) gamma rays and X rays

gamma rays and X rays

Physical agents for controlling microbial growth include all the following except: A) ultraviolet radiation B) boiling water C) HEPA filters D) pasteurization E) hydrogen peroxide

hydrogen peroxide

The chemical agent that produces highly reactive hydroxyl-free radicals and also decomposes to O2 gas is: A) Cidex B) cationic detergents C) hydrogen peroxide D) chlorhexidine E) iodophors

hydrogen peroxide

Which of the following microbial forms have the highest resistance to physical and chemical controls? A) naked viruses B) protozoan cysts C) fungal spores D) hydrogen peroxide E) yeast

hydrogen peroxide

All the following act as surfactants except: A) detergents B) soaps C) quats D) alcohols E) hypochlorites

hypochlorites

Which is correct regarding the rate of microbial death? A) cells die at increasingly greater rates B) only older cells die in a culture C) involves the permanent termination of an organisms vital processes D) upon contact with the control agent, all cells die at one time E) cells become metabolically inactive but are never killed

involves the permanent termination of an organisms vital processes

All of the following are alkylating control agents except: A) ethylene oxide B) iodophor C) glutaraldehyde D) formaldehyde E) chlorine dioxide

iodophor

Disinfection of beverages such as apple juice, milk, and wine, is optimally achieved by: A) pasteurization B) chlorination C) moist heat autoclave D) filtration E) boiling water

pasteurization

The process of using a cleansing technique to mechanically remove and reduce microorganisms and debris to safe levels is: A) disinfection B) sterilization C) antisepsis D) sanitization E) degermation

sanitization

Ethylene oxide is: A) sporicidal B) only effective with high heat C) the active agent in household bleach D) used as an antiseptic against anaerobes E) a halogen

sporicidal

Which of the following types of control agents would be used to achieve sterility? A) virucide B) bactericide C) germicide D) sporicide E) fungicide

sporicide

Sterilization is achieved by: A) flash pasteurization B) hot water C) boiling water D) steam autoclave E) all of the choices are correct

steam autoclave

The process that destroys or removes all microorganisms and microbial forms including bacterial endospores is: A) disinfection B) sterilization C) antisepsis D) sanitization E) degermation

sterilization

The shortest time required to kill all the microbes in a sample at a specified temperature is called the: A) thermal death point (TDP) B) thermal death time (TDT) C) sporicidal time D) death phase point E) none of the choices are correct

thermal death time (TDT)

Which of the following is not a heavy metal? A) tincture of iodine B) Merthiolate C) silver nitrate solutions D) zinc E) Mercurochrome

tincture of iodine

Which control method would not be a suitable choice for killing mycobacteria in a capped culture tube? A) ultraviolet (germicidal) light B) gamma rays C) 121 C at 15 psi for 15 minutes D) 160 C for 2 hours E) all of the choices are correct

ultraviolet (germicidal) light

Microbiological contaminants are best described as: A) unwanted microbes present on or in a substance B) any and all microbes present on or in a substance C) pathogenic microbes present on or in a substance D) vegetative microbes present on or in a substance E) none of the choices are correct

unwanted microbes present on or in a substance

The easiest microbial forms to kill or inhibit are: A) naked viruses B) vegetative bacteria and fungi C) endospores D) protozoan cysts E) mycobacteria and staphylococci

vegetative bacteria and fungi