Controlling Microbes Flashcards

1
Q

detergents act as

A

wetting agents and emulsifiers

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2
Q

is the single most important step to achieving control

A

hand washing

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3
Q

hospital acquired infections

A

nosocomial infections

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4
Q

what is most common and most reliable mechanism in regards to food/ production

A

heat treatment

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5
Q

agent which kill microbes

A

-cide

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6
Q

kill microorganisms and viruses, but not

necessarily endospores

A

germicide

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7
Q

agent which prevents microbial growth

A

-static

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8
Q

the complete removal or destruction of all microbes

Even spores and viruses are removed

A

sterilization

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9
Q

Killing C. botulinum endospores

A

commercial sterilization

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10
Q

the killing, inhibition or removal of most disease causing
microbes
Also reduces the total microbial population

A

disinfection

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11
Q

agents, generally chemical, used on inanimate

objects

A

disinfectants

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12
Q

form of disinfection designed to prevent infection

by microorganisms in/on living tissue

A

Antisepsis

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13
Q

chemical agents that kill or inhibit

growth of microorganisms when applied to tissue

A

Antiseptics

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14
Q

substantial reduction of microbial population

to levels that meet accepted public health standards

A

sanitation

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15
Q

treatment to reduce microbes to a level considered safe

A

decontamination

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16
Q

removal of microbes from a surface by

mechanical means

A

Degerming

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17
Q

what are the conditions affecting the effectiveness of antimicrobial activity

A
What microorganisms are present
Amount of contamination
Concentration or intensity of an antimicrobial agent
Duration of exposure
Temperature
Local environment
Composition of the item
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18
Q

how do microbes die

A
Microbes are not killed instantly
Microbes are considered to be dead
when they are unable to reproduce in
conditions that normally support their
reproduction
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19
Q

usually enhance the effectiveness of an agent

A

higher temperatures

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20
Q

what do physical methods of control include

A
Mechanical removal
Filtration
Drying (reducing water availability)
Heat
Irradiation
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21
Q

Reduces microbial population or sterilizes
solutions of heat-sensitive materials by
removing microorganisms
Also used to reduce microbial populations in air
Often used in conjunction with other methods

A

filtration

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22
Q

what are the two main types of filtration

A

depth and membrane filters

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23
Q

Thick fibrous or granular filters that remove microorganisms by physical screening, entrapment, and/or adsorption

A

depth filters

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24
Q

Porous membranes with defined pore sizes that remove

microorganisms primarily by physical screening

A

membrane filters

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25
Q

(freeze drying)

Widely used to preserve foods

A

Lyophilization

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26
Q

Typically the most cost effective method

Relatively fast, reliable, safe and inexpensive

A

heat

27
Q

two types of heat control

A

dry and moist

28
Q

Effective against all types of microorganisms

Degrades nucleic acids, denatures proteins, and disrupts membranes

A

moist heat

29
Q

Destroys most microorganisms and viruses
Does not destroy endospores
Not effective means of sterilization

A

boiling

30
Q

developed to avoid spoilage of wine
Controlled heating at temperatures well below boiling
Does not sterilize but significantly reduces organisms
Used to increase shelf life of food

A

Pasteurization

31
Q

Preferred method of sterilization

A

Pressurized steam

32
Q

why is dry heat not as effective as moist heat

A

Sterilization with dry heat requires longer times and higher temperatures

33
Q

method of dry heat sterilization
Oxidizes cell to ashes
Used to destroy medical waste and animal carcasses

A

incineration

34
Q

stops microbial reproduction due to lack of liquid water
some microorganisms killed by ice crystal disruption of cell membranes
Kills up to 50% of microbes

A

freezing

35
Q

Low temperatures slow down or
stop enzymatic reactions – slowing
microbial growth and reproduction

A

refrigeration

36
Q

what does a shorter wavelength mean

A

higher frequency and more energy

37
Q

this can be ionizing or non-ionizing

A

radiation

38
Q

Non-ionizing radiation
Damages DNA causing thymine dimers
Generates free radicals

A

ultraviolet radiation

39
Q

Includes Gamma radiation, X-rays
Radiation able to strip electrons from atoms (forms ions)
Penetrates deep into objects
Causes damage to DNA and proteins

A

ionizing radiation

40
Q

what are Chemical Agents of Control

A

Disinfectants
Antiseptics
Antibiotics

41
Q

conditions influencing antimicrobial effectivness

A

highly effective, Activity in presence of organic material, Compatibility with material being treated, toxicity, residue, storage, cost/availability, environmental risk

42
Q

Phenolics

A

cresols

43
Q

Bisphenols

A

triclosan

44
Q

alcohols

A

– isopropyl, ethanol

45
Q

peroxides

A

hydrogen peroxide

46
Q

halogens

A

iodine, chlorine

47
Q

heavy metals

A

silver, copper

48
Q

detergents

A

anionic, cationic

49
Q

sterilizing gases

A

ethylene oxide, ozone

50
Q

who were phenolics first used by

A

Lister in 1870

51
Q

what do phenolics do

A

Act by denaturing proteins and disrupting cell membranes
effective in presence of organic material and long lasting
Commonly used as laboratory and hospital disinfectants

52
Q

what percent isopropyl or ethyl alcohol

kill vegetative bacteria and fungi

A

60-80%

53
Q

Coagulates proteins and essential enzymes and
damages lipid membranes
Commonly used as antiseptic and disinfectant

A

alcohols

54
Q

what are the limitations to alcohol

A

Evaporates quickly, limiting contact time
May damage material such as rubber and
some plastics

55
Q

Powerful oxidizing agent
Effectiveness depends on surface being treated
Readily biodegradable

A

hydrogen peroxide

56
Q

is hydrogen peroxide more effective on living tissue or inanimate objects

A

inanimate objects

57
Q

Used as a skin antiseptic in tincture or iodophore
Kills vegetative cells but not reliable with
endospores

A

iodine

58
Q

alcoholic solution

A

tincture

59
Q

carrier molecule

A

iodophore

60
Q

Oxidizing proteins and other cell components

common disinfectant

A

halogens-iodine

61
Q

Important disinfectant
Caustic to skin and mucous membranes
Destroys vegetative bacteria and fungi, but not
spores

A

halogens-chlorine

62
Q

combine with enzymes and
proteins interfering with function
High concentrations are toxic to human tissue

A

heavy metal compounds

63
Q

Organic molecules with hydrophilic and hydrophobic ends
Act as wetting agents and emulsifiers facilitating mechanical removal of organisms
Not disinfectant

A

detergents

64
Q

Quaternary ammonium compounds
Are effective disinfectants
Positive charge attracted to negatively charged cells,
reacting with the membrane

A

cationic detergents