Ch. 9

the most efficient sterilizing conditions in a steam autoclave are

121 degrees Celsius at 15 psi for 15 minutes

which of the following is not a factor that affects germicidal activity?

All of these are factors

Which of the following factors will influence the action of microbial agents?

All of these will influence the action

The lowest temperature needed to kill all microbes in 10 minutes is the

Thermal death point (TDP)

HEPA filters are used to remove microbes from

air

alcohols

all of the choices are correct

antimicrobial agents can target the cell wall by

all of the choices are correct

hydrogen peroxide can be

all of the choices are correct

which of the following items are typically irradiated in order to kill microbes?

all of the choices are correct

The betadine swab before blood donation is an example of

antisepsis

scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is

antisepsis

the alcohol wipe before an injection is an example of

antisepsis

the method of removing vegetative life forms from living surfaces is termed

antisepsis

the use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is

antisepsis

What instrument is most effective for pressure-temperature sterilization?

autoclave

which of the following microbial forms have the highest resistance to physical and chemical controls?

bacterial endospores

placing organisms at 4 degrees C is

bacteriostatic

filtration can result in sterilization of serum and blood products

by removing viruses

which is correct regarding the rate of microbial death

cells in a culture die at a constant rate

the compound that is organic base containing chlorine and two phenolic rings, and is used increasingly for mucous membrane irrigation, obstetrical washes, hand scrubbing, and prepping surgical skin sites is

chlorhexidine

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

chlorine

each of the following is the target of antimicrobial agents except

cytoplasm

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

denature

removal of moisture by dehydration is called

desiccation

please choose the answer that best completes the blanks of this sentence in the correct order. A(n) _____ would be used to destroy bacteria on a countertop whereas a(n) _____ would be used on skin prior to making an incision.

disinfectant; antiseptic

the method of removing vegetative microbial life forms from inanimate objects is termed

disinfection

the use of a physical or chemical process to destroy vegetative pathogens is

disinfection

surfactants work by

disrupting membrane integrity

select the microorganism that is least resistant to chemical and physical control measures.

enveloped viruses

regarding use of heat to control microbial growth, dry heat at lower temperatures is as effective as moist heat at the same temperature

false

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

filtration

choose the microbial control method that neither inhibits nor kill microbes, but instead physically removes them from liquids or air.

filtration

choose the aldehyde that is the most toxic, limiting its clinical usefulness

formaldehyde/formalin

All of the following pertain to hypochlorites except

found in iodophors

which of the following forms of radiation is in order from the most penetrating to the least penetrating?

gamma, x rays, cathode

which of the following is not used as an antiseptic?

glutaraldehyde

physical agents for controlling microbial growth include all of the following except

hydrogen peroxide

the chemical agent that produces toxic and reactive free radicals is

hydrogen peroxide

heavy metals work by

inactivating proteins

choose the method used to sterilize a bacteriologic loop before and after inoculation a culture in the laboratory

incineration

in lab, inoculating loops are sterilized using

incineration

all of the following disrupt the cytoplasmic membrane except

iodine

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

lyophilization

which of the following does not affect microbial nucleic acids?

moist heat

___ heat is more rapidly effective and efficient compared to ____ heat.

moist, dry

disinfection of beverages such as apple juice, milk, wine is optimally achieved by

pasteurization

Microbial death occurs when there is

permanent loss of reproduction

Which of the following acids is not used to destroy or inhibit microbial cells in food?

phosphoric acid

pasteurization

reduces the number of vegetative forms

which of the following represents the use of osmotic pressure as a microbial control method?

salting meat

A cleansing method that mechanically removes microbes and other debris to reduce contamination is

sanitization

the process of using a cleansing technique to mechanically remove and reduce microorganisms and debris to safe levels is

sanitization

ethylene oxide is

sporicidal

which of the following types of control agents would be used to achieve sterility?

sporicide

sterilization is achieved by

steam autoclave

the process that destroys or removes all microorganisms and microbial forms including bacterial endospores on inanimate objects is

sterilization

the removal of all life forms inanimate objects is termed

sterilization

select the statement that describe the antimicrobial activity of chlorhexidine

targets cell membrane components and denatures proteins

the shortest time required to kill all the microbes in a sample at a specific temperature is called the

thermal death time (TDT)

choose the statement that identifies the major disadvantage of both cold and desiccation in terms of microbial control

these methods are bacteriostatic rather than bactericidal

Please choose the answer the best completes the blanks of this sentence in the correct order. The shortest length of time required to kill all test microbes at a specified temperature is the thermal death _____ whereas the lowest temperature required t skill al microbes in a sample within 10 minutes is the thermal death ______.

time; point

select the most disadvantageous characteristic of phenolics

toxicity

a method for sterilizing milk, called ____ treatment, uses 134 degrees c for 1 to 2 seconds.

ultra high temperature

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

ultraviolet

which control method would not be a suitable choice for killing mycobacterium in a capped culture tube?

ultraviolet (germicidal) light

the easiest microbial forms to kill or inhibit are

vegetative bacteria and fungi

agents that can denature microbial proteins include all of the following except

x rays