Micro Ch.9
T/F: Tinctures and ointments are two types of heavy metal germicides
True
dry heat occurs in the forms of
an open flame and hot air oven
disinfectants can be toxic or harmful to ____ tissues
animal
Phenol is now limited in its use to
animal quarters, cesspools, and drains
____ is the destruction of most microbes using chemicals on a living surface such as the skin.
antisepsis
chlorhexidine solutions are commonly used for
antisepsis
degermation and ____ can be accomplished with the same procedure
antisepsis
iodine compounds are commonly used for
antisepsis of skin, treatment of skin wounds, and disinfection of medical equipment
A chemical agent applied directly to exposed body surfaces (skin and mucous membranes) wounds, and surgical incisions to destroy or inhibit pathogens is a(n)
antiseptic
A chemical agent applied directly to exposed body surfaces (skin and mucous membranes), wounds, and surgical incisions to destroy or inhibit pathogens is a(n) ____.
antiseptic
alcohols are commonly used for
antiseptic preparation for skin and degarmation of skin
Antimicrobial solutions with water as the solvent are called ___ solutions, whereas antimicrobial solutions with alcohol or water-alcohol mixtures as the solvent are called _____.
aqueous; tinctures
___ is a procedure or process designed to prevent entry of infectious agents
asepsis
a(n) ____ is a sterilization chamber that allows the use of steam under pressure to sterilize materials
autoclave
chlorohexidine can kill/activate most
bacteria and viruses
chlorohexidine is reliably
bactericidal
what type of agent will kill bacteria?
bactericidal
Any process or agent that inhibits bacterial growth is referred to as _____.
bacteriostatic
A ___ agent will inhibit the growth of bacteria, whereas a ___ agent will kill bacteria
bacteristatic; bactericidal
which items can be sanitized by boiling water prior to safe, acceptable use in humans?
bedding and clothing, utensils, and drinking water
which of the following substances should be removed from items before decontamination?
blood and saliva
moist heat occurs in the forms of
boiling water and steam
iodine compounds ___ kill endospores
can
which type of detergents are more effective?
cationic
which of the following compounds are commonly used as gaseous sterilants or disinfectants?
chloride dioxide and ethylene oxide
gaseous and liquid ___ compounds are mostly used for large-scale water disinfection
chlroine
The root -_____ is used to indicate the killing of microorganisms.
cide
which of these items is considered noncritical for sterilization?
crutches and stethoscope
which of the following are limitations to the use of radiation for sterilization?
damage to some materials and danger to machine operators
____ involves the permanent termination of a particular organism's vital processes, and special qualifications are often needed to define and delineate this phenomenon in microbes
death
the lowest temperature that achieves sterilization in a given quantity of broth culture upon a 10-minute exposure is referred to as the thermal
death point
the shortest length of time required to kill all test microbes at a specified temperature is referred to as the thermal
death time
____ is the general term used for the reduction of the microbial load in order to lower the possibility of infection of spoilage
decontamination
____ is the mechanical removal of most microbes from an animate or inanimate surface
decontamination
____ is the physical removal of surface oils, debris, and soil from skin to reduce the microbial load.
degermation
the disruption of proteins from their native state is known as
denaturation
iodine compounds typically kill microbes by
denaturing proteins
chlorhexidine typically kills microbes by
denaturing proteins and disrupting the cell membrane
if an agent acts on the cell wall, it can
digest the cell wall and block cell wall synthesis
The goal of regular pasteurization methods is the _____ of the liquid.
disinfection
UV radiation is usually used for ____.
disinfection
examples of ___ include immersing thermometers in an iodine solution between uses
disinfection
boiling water can be an effective means of ___ in the clinic and home
disinfection and santization
Glutaraldehyde typically kills microbes by
disrupting enzyme function and altering amino acids
ethylene oxide typically kills microbes by
disrupting enzyme function and blocking DNA replication
Cationic detergents typically work by
disrupting the cell membrane
Alcohols usually affect microbes by
disrupting the cell membrane and disrupting cell surface tension
Phenolics typically kill microbes by
disrupting the cell membrane, disrupting the cell wall, and denaturing metabolic enzymes
higher concentrations of alcohols usually affect microbes by
dissolving membrane lipids
which of the following are examples of sanitization?
doing laundry, scouring a countertop with soap, washing utensils
Flaming the inoculating loop in the laboratory is an example of ___ heat sterilization
dry
____ heat requires longer exposure times and higher temperatures than ___ heat
dry; moist
an object can be
either sterile or not sterile
viruses, prions , and ___ are relatively resistant to heat
endospores
The two microbial agents that are least resistant to physical and chemical control methods include:
enveloped viruses and fungi
chlorine compounds usually kill microbes by denaturing metabolic
enzymes
_____ oxide is valuable for sterilization of heat-sensitive objects such as plastics, surgical and diagnostic appliances, and spices, but other related gases are available that are less toxic.
ethylene
the effect of a germicide is affected by the time of ____.
exposure
T/F hydrogen perioxide is used for disinfection of drinking water
false
T/F: household cleaners are often alcohol based.
false
T/F: the effectiveness of an antimicrobial agent is only governed by time
false
Microbes can be effectively removed from air by ____.
filtration
when decontaminating a metal instrument that has blood on it, you should
first remove the blood, then treat with a chemical disinfectant
the ___ method of pasteruization exposes liquids to higher temperatures for a very short time, whereas the ___ method uses lower temperatures for a longer period
flash; batch
An agent that kills fungal spores, hyphae and yeasts is called a ____
fungicide
which of the following are types of ionizing radiation?
gamma rays and X-rays
____ are chemical agents that kill non-endospore forming pathogens
germicides
which of the following are suited for sterilization in an autoclave?
glassware and broth media
in what unit is radiation measured?
grays
sepsis is defined as
growth of microorganisms in the blood or other tissues
which of the following is the most common physical agent used to control microbes?
heat
which of the following are not usually destroyed or inactivated with regular pasteurization methods?
heat-resistant microbes and endospores
Math each item commonly found in a health care setting with its level of chemical decontamination.
high - urinary catheter intermediate - respiratory equipment low - electrodes on an EKG machine
which level of chemical decontamination by a germicide can result in sterilization?
high level
Match each item commonly found in health care setting with its level of chemical decontamination
high- replacement hip joint intermediate- thermometers low- furniture in exam room
the dry oven is not suitable for items that may burn at ____ temperatures, or for liquids which will ____.
high; evaporate
in most cases, an agent with a ____ concentration will be more germicidal
higher
_____ ____ typically kills microbes by producing toxic free radicals
hydrogen peroxide
Plasmolysis of bacteria in food occurs when high concentration of salt or sugar are added to the foods creating a ___ environment
hypertonic
the two primary iodine preparations are free iodine and
idophors
virucides ____ viruses
inactivate
heavy metals typically kills microbes by
inactivating proteins
sterilization methods are usually reserved for
inanimate objects
which of the following is NOT an example of using moist heat to sterilize or disinfect materials?
incineration
which are examples of using dry heat to sterilize materials?
incineration and hot air oven
_____ are complexes of iodine and alcohol
iodophors
the two primary iodine preparations are free iodine and
iodophors
which of the following should be considered when initially choosing a method of microbial control?
is it cost and labor-efficient? Is it safe? Is sterilization needed? Is the item reusable or disposable? will it penetrate effectively? can it withstand physical or chemical treatments?
ethyl and ___ alcohols are effective in microbial control
isopropyl
A bactericide ____ bacteria
kills
the disadvantage of UV radiation include the inability to penetrate ___ or solids
liquids
filtration is used to prepare____ that cannot be heated, and to remove ____ contaminants that are common source of infection and spoilage
liquids; airborne
quaternary ammonium compounds are considered to be ___-level disinfections
low
what method preserves microorganisms (and other substances) by freezing and then drying them directly from the frozen state?
lyophilization
____ is a method for preserving microorganisms (and other substances) by freezing and then drying them directly from the frozen state
lyphoization
The cell __ is responsible for preventing the loss of important molecules and stopping the entry of damaging substances.
membrane
younger, active cells die more quickly when exposed to microbial agents because they are more ___ active
metabolically
Phenolics are
microbicidal
Regarding the use of the terms microbicidal and microbistatic, higher temperatures are usually __, whereas lower temperatures are usually __.
microbicidal, microbistatic
An agent's effect on cells is known as its ___ of action
mode
agents that are highly selective in their targets are usually effective against a ___ microbes
narrow
Which of the following are not suited for sterilization in an autoclave?
oils and powders
heavy metal germicides come in which of the following forms?
ointments and aqueous solutions
to prepare a common disinfectant like Lysol by performing a 1:200 dilution, you would mix
one part lysol to 200 parts water
Disinfection destroys
only vegetative bacterial cells
dry oven sterilization is not useful for plastics, cotton and ____.
paper
items are classified as critical, semicritical, or noncritical based on
parts of the body contacted by the item
the heat treatment of perishable liquids to destroy heat-sensitive vegetative cells and prevent infection and spoilage is called
pasteurization
if the cell membrane is damaged by an agent, the cell loses its membrane ___ and cannot prevent loss or entrance of substances.
permeability
temperature and radiation are two ___ method used to control microbes.
physical
Although they do have some drawbacks, heavy metals are used for
preservatives, prevention of infection, controlling microbial growth on objects, and skin cleansing
cold treatment and desiccation are reliably used for
preventing microbial growth
The four general cellular targets of antimicrobial agents are the cell wall, the cell membrane, nucleic acid synthesis, and _____ function.
protein
glutaraldehyde affects what type of macromolecules?
proteins
____ is electromagnetic waves to rays, such as those of light given off from an energy source
radiation
The inability to __ is the practical definition of microbial death.
reproduce
Prions are
resistant to heat and chemicals
Which are goals of pasteurization?
retention of liquid qualities and reduction of microbial load
The synthesis of proteins involves organelles known as ___ in a process called translation
ribosomes
washing laundry, doing dishes, and wiping down counters with soap are all examples of
sanitization
what is the thermal death time?
shortest length of time required to kill all test microbes at a specified temperature
___ and mercury are heavy metals that are still used in germicidal preparations.
silver
Antiseptics are used to destroy vegetative bacteria on
skin
soaps and quats are commonly used for
skin cleansing, disinfection of facilities, sanitization of the home, and sanitization of food preparation equipment
the main effect of cold treatment is to
slow the activity of microbes
which of the following are effects of ionizing radiation on food products?
small decreases in thiamine, killing bacterial pathogens, and changes in texture of some foods
___ objects are more reliably disinfected with a germicide
smooth
which of the following compounds is/are typical examples of sanitizers?
soap and detergent
Alcohols are not effective against naked viruses and bacterial
spores
A ___ agent can also be a sterilant because it can destroy bacterial endospores and leave an object free of all life.
sporicidal
A ___ is an agent that can destroy bacterial endospores
sporicide
what type of agent specifically destroys bacterial endospores?
sporicide
the root- ___ is used to indicate the inhibition of microbial growth
static
An object is ____ if it is free of all viable microorganisms including viruses
sterile
An object is ____ if its free of all viable microorganisms including viruses
sterile
A process that completely removes or destroys all viable microorganisms, including viruses, from an object or habitat is referred to as
sterilization
The goal of __ is to remove or destroy all viable microorganisms including viruses.
sterilization
Hydrogen peroxide is commonly used for
sterilization of diagnostic instruments, skin and wound cleaning, and disinfection of medical equipment
____ is the destruction of all microbial life, whereas ____ destroys most microbial life, thus reducing contamination on inanimate surfaces
sterilization; disinfection
A ____ is an agent that disrupts the lipid bilayer of membranes and alters the membrane's permeability.
surfactant
Which of the following are examples of degermation?
surgical handscrub and immersing skin in chemicals
which of the following are examples of antisepsis?
swabbing skin with alcohol before a venipuncture and washing hands with a germicidal soap
As the most extensively used chlorine compounds, hypochlorites are used for
swimming pool treatments, food equipment sanitation, wound treatment, skin cleansing, and household cleaning
which factors must be considered to adequately sterilize using using heat?
temperature, length of exposure and presence of water
what is desiccation?
the dehydration of microbes for preservation
an important side effect of adding antimicrobial chemicals to soaps and detergents used in the home is
the development of resistance
What is filtration?
the straining of a fluid or air through a membrane to trap microorganisms
UV radiation is effective at disinfecting ___ solid substances
the surfaces of
what is incineration ?
the use of dry heat to destroy all microbes
Death of microorganisms is hard to detect because:
they have no obvious vital signs
Sterilization methods are often used
to prepare instruments for surgery and for inanimate objects
T/F: Soaps and detergents are sufficient on their own for home cleaning, and additional antimicrobial agents are likely to lead to resistance in the microbes
true
True or False: The primary targets of microbial control are microorganisms that cause infection or spoilage.
true
____ radiation is a type of nonionizing radiation
ultraviolet
____ radiation is most lethal from 240 mm to 280 nm
ultraviolet
liquids can be sterilized by suctioning through a filter with uniform pores. Viruses can be eliminated from the liquid by
using a small pore size
What is a concern when attempting to control a microbial population?
variable resistance
Which of the following are effectively destroyed with regular pasteurization methods?
vegetative bacteria, vegetative fungi, viruses
which of the following statements microbial sensitivity to heat are correct?
vegetative cells of endospore-formers are just as susceptible to heat killing as vegetative cells of other species and nematodes are very susceptible to heat killing
which of the following microbial forms are relatively resistant to heat?
viruses and endospores
which of the following statements regarding microbial sensitivity to heat are correct?
viruses are among the more heat-stable microbes and pathogens are equally susceptible to heat killing as other microbes
desiccation can preserve foods by reducing the availability of ___ to their metabolism
water
adding pressure to water in an autoclave increases boiling point of ___ and increases the temperature of ___.
water; steam
agents that are least selective in their targets are usually effective against a ___ range of microbes
wide
Aldehydes are organic substances that contain a ___ functional group on a terminal carbon
-CHO
which of the following are some of the desirable qualities in a germicide?
-Selective toxicity -Solubility in a solvent -Broad-spectrum action -Penetrating ability -Rapid action
what are tinctures?
Antimicrobial solutions with alcohol or water-alcohol mixtures as the solvent
A sterliant is a chemical that
Destroys all life forms, including endospores
True or False: There are several degrees of sterility, based on the destruction of endospores
False
