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Microbiology Chapter 9

Terms in this set (44)

sterilization
The process that completely destroys all microbial life, including spores and viruses.

inanimate objects such as surgical instruments
ex: autoclave ***
sterilants
chemical agents capable of destroying endospores. ***
disinfection
Physical process or chemical agent to destroy vegetative pathogens but not bacterial endospores. Removes harmful products of microorganisms (toxins) from material.

Normally used on inanimate objects. boiling food utensils.
ex: bleach, iodine, heat (boiling) ***
decontamination/sanitization
cleansing technique that mechanically removes microorganisms as well as other debris to reduce contamination to safe levels.

important to restaurants, breweries. used for cooking utensils for reuse.
ex: soaps, detergents, dishwashers ***
antisepsis
reduces the number of microbes on the human skin; a form of decontamination but on living tissues.

scrubbing the skin
ex: alcohol, surgical hand scrubs ***
endospores
the goal of any sterilization process is the destruction of bacterial ____________. ***
infection
Primary targets of control are microbes capable of causing _______ or spoilage.
processes
The terms sterilization and disinfection (and so on) refer to __________.
agents
_________ that are used in the process may be - "cidal" or "-static". (Know what these suffix means) ***
death rate
Factors affecting _______ _______ include:
# of microbes
temperature and pH
concentration of agent
mode of action of agent
cell wall
Cellular target in which chemical agents damage by blocking synthesis or digesting it. examples are chemicals, detergents, alcohol.
cytoplasmic membrane
cellular target in which agents physical bind to the lipid layer. this opens it up and allows damaging chemicals to enter the cell and important ions to exit the cell. example is detergents.
cellular synthesis
cellular target in which agents can interrupt proteins via ribosomes and inhibiting proteins needed for growth and metabolism and preventing multiplication. agents can cause mutations.
ex: formaldehyde, radiation, ethylene oxide ***
proteins
cellular target where some agents are capable of denaturing this. results in a breakdown of structure. Agents may attach to the active site and prevent it from interacting with its chemical substrate.
ex: most heat, alcohol, phenolics
false
True or false: there is a universal method for microbial control.
radiation
energy emitted from atomic activities and dispersed at high velocity through matter or space
uv radiation
_______ ______ can be used to disinfect hospital rooms and air as well as treating drinking water.
filtration
effective method to remove microbes from air and liquids. ***
yes
Can filtration sterilize a gas/liquid? ***
osmotic pressure
adding large amounts of salt and sugar to foods creates a hypertonic environment for bacteria, causing plasmolysis is an example of _______ ___________.
no
Does a high osmotic pressure sterilize?
microbicidal
elevated temperatures are ____________. ***
microbistatic
lower temperatures are _______________. ***
moist heat
Autoclaving and boiling water are 2 examples of ____________ _____________. ***
lower, shorter
Most heat operates are higher/lower temperatures and shorter/longer exposure times to achieve the same effectiveness as dry heat.
microbicidal
The __________ effect of moist heat is that it coagulates and denatures proteins. ***
dry heat
dehydrates the cell and denatures proteins. at very high temperatures it oxidizes cells, burning them to ashes. hot air or an open flame ranging from 160 degrees C to thousands of degrees C.
true
true or false: most microbes are not adversely affected by gradual cooling, long-term refrigeration or deep-freezing
desiccation
vegetative cells directly exposed to normal room temperature gradually become dehydrated. some microbes are killed, some are resistant.
lyophilization
a combination of freezing and drying; used to preserve microorganisms and other cells in a viable state for many years.
germicidal
Nature of microorganisms being treated, nature of material being treated, degree of contamination, time of exposure, strength/chemical action are all factors effecting the ___________ activity of chemicals.
gamma rays, XR
examples of nonionizing radiation
UV
example of ionizing radiation
sterilization
nonionizing radiation is an example of ___________.
disinfectant
UV light is an example of a ____________.
incinerator, dry oven, autoclaving
What methods of heat are known sterilants? ***
boiling water, pasteurization
What methods of heat are disinfectants? ***
air
What physical agent of filtration is involved in decontamination? ***
liquids
Filtration of _________ are a process of sterilization. ***
A
Which antimicrobial control method would be hardest to accomplish during routine care of patients in a hospital setting?
a: sterilization
b:antisepsis
c: disinfection
d: decontamination
endospores
Microbial control methods that kill ______ are able to sterilize. ***
filtration
The best method to sterilize heat-sensitive liquids is _____.
enveloped
What group of bacteria is easiest to kill?
endospores, prions
What two groups of bacteria are hardest to kill? ***
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