Ch. 11 Microbial Control Study Guide

1) Decontamination

physical, chemical, and mechanical methods to destroy or reduce undesirable microbes in a given area

1) Physical agents:

Heat and radiation

1) Chemical agents:

antiseptics

1) Physical agents - Heat can be either

dry or moist

1) Physical agents - Dry Heat can be either

incarnation or dry oven

1) Physical agents - Incineration leads to:

sterilization

1) Physical agents - Dry one oven leads to:

sterilization

1) Physical agents - Moist Heat can be:

steam under pressure, boiling water, pasteurization

1) Physical agents - Steam under pressure leads to:

sterilization

1) Physical agents - Boiling water/ Pasteurization leads to:

disinfication

1) Physical agents - Radiation can be either

Ionizing or nonionizing

1) Physical agents - Ionizing

X-ray, cathode, gamma

1) Physical agents - Nonionizing:

UV

1) Physical agents - X-ray, cathode, gamma leads to:

sterilization

1) Physical agents - UV leads to:

disinfection

1) Chemical agents:

gases or liquids

1) Chemical agents - Gases leads to:

sterilization or disinfection

1) Chemical agents - Liquids can be either for:

animante or inanimate objects

1) Chemical agents - Liquids on animate objects leads to:

antisepsis

1) chemical agents - Liquids on inanimate objects leads to:

disinfection or sterilization

1) Mechanical methods:

Filtration

1) Mechanical methods - Filtration can be either:

air or liquid

1) Mechanical method - Air filtration leads to:

disinfection

1) Mechanical methods - Liquid filtration leads to:

sterilization

1) Disinfection

destruction or removal of VEGETATIVE pathogens on inanimate objects

1) Sterilization

COMPLETE removal or destruction of all viable microbes on Inanimate objects

1) Antisepsis

Destroy or inhibit VEGETATIVE pathogens on body surfaces

1) Microbiostasis

slows down growth of microbes (freezing, refrigeration, drying, chemicals)

1) Germicide

any chemical agent used to kill pathogenic microbes

1) Sanitation

cleansing technique that removes microbes from a inanimate object to reduce the risk for infection or spoilage

1) Degermination

Physically (wipping, scrubbing) reducing pathogenic microbes from body surfaces

2) Hard to kill:

prions and bacterial endospores

2) Moderate to kill:

protozoan cyst, fungal zygospores, naked viruses

2) easy to kill:

Vegetative cells

3) Death of microbe:

the permanent loss of reproductive capability even on optimum growth conditions

3) Factors that affect microbial death (6 factors)

1. number of microbes

2. nature of microbes

3. temperature and pH

4. concentration

5. mode of action

6. solvents, organic matter or inhibitors

4) Antimicrobial agent modes of action and what causes it - 1. Cell wall:

becomes fragile and cell lyses (drugs, detergent, alcohol)

4) Antimicrobial modes of action - 2. Cell membrane:

looses integrity, (disrupt surface tension) leaks and die. stops being selective

4) Antimicrobial modes of action - 3. Protein and nucleic acid synthesis

prevents replication, transcription, translation, and peptide bond formation which leads to stop of protein synthesis.

4) Antimicrobial modes of action and what causes it - 4. Protein structure and function

disrupts or denature protein (alcohol, phenols, acids and heat)

5) cold makes the microbes:

stop growing or slow growing

5) heat makes the microbes:

dead

5.a) Moist heat is more…

effective than dry heat

5.a) Most heat requires ___ temperature and ___ exposure than dry heat

less (60-135 Celsius)

5.a) Dry heat required tempt:

160 to thousands celsius

5.a) Dry heat ___ cell, which removes __ from cell required for metabolic reactions

dehydrates, water

5.a) Dry heat inceneration alters:

protein structure

5.b) Thermal Death Time (TDT):

shorter length of time required tp kill all microbe at specific temperature

5.b) Thermal Death Point (TDP):

lowest temperature required to kill all microbes in a sample in 40 min

5.b) TDT

combination of time and temperature

5.c) Moist heat methods:

steam under pressure, nonpressured steam, boiling water pasteurization

5.c) Moist heat methods: On Steam under pressure the temperature ____ by pressure

rises

5.c) What is the tool used in steam under pressure method?

autoclave

5.c) What is the temperature/pressure used in the steam under pressure method?

121C/15 psi (15 above normal)

5.c) What is the time to kill microbes in light loads on the autoclave?

10 min

5.c) What is the time to kill microbes in heavy loads on the autoclave?

40 min

5.c) What is the time to kill microbes in moderate loads on the autoclave?

20 min

5.c) Moist heat method - Nonpressured steam/ Tyndalization is a non___ (intermittent) sterilization for substances that would be destroyed by ___

continuous, autoclave

5.c) Moist methods - Boiling water: is disinfectation or sterilization?

disinfection

5.c) The temperature needed on boiling water to destroy ___ pathogens is ___

vegetative, 100C

5.c) Pasteurization is the: ___ of ___

disinfection, beverages

5.c) On pasteurization __ is applied to destroy __ without affecting ___ or __

heat, pathogens, flavor, value

5.c) Flash Method

used on a 71C temperature for 15 second on milk

5.c) On the flash method the milk still has a lot of __ that’s why it __ fast

microbes, spoils

5.c) Ultrapasteurized method serves to keep __ for __ time

milk, longer

5.d) Dry heat uses __ temperature than moist heat

higher

5.d) Dry Heat - Incineration includes:

flame, electric heating,

5.d) Incineration (effect on microbes):

reduces microbes to ashes

5.d) Dry heat - Hot air includes:

oven, heated air

5.d) Hot air (effect on microbes)

coagulate proteins

5.e) Cold, microbisotatic is used to:

preserve food, media, cultures

5.e) Desiccation/Dehydration is not that effective because:

many cells regain ability to grow when water is reintroduced

5.d) Lyophilization is:

freeze and dry

Lyophilization serves to

preserve for long periods of time

5.d) Cold, freezing and desiccation are __ methods which means they should not be treated as methods of __ or __, since antimicrobial effects are __

erratic, disinfection, sterilization, uncertain

6) Radiation

energy emitted form atomic activities

6.a) Ionizing radiation is __ penetrating

deep

6.a) Ionizing radiation method includes:

x-ray, cathode, gamma

6.a) Ionizing radiation effects on cell:

breaks dna

6.a) Nonionizing radiation is __ penetrating

little

6.a) Nonionizing radiation includes:

UV

6.a) Nonionizing radiation effects on cell:

interferes with replication which causes mutations

6.b) UV os used to disinfect:

large scale surfaces

6.b) Ionizing radiation is used on:

used one products that cannot be heated

7) Filtration

the physical removal of microbes by passing gas or liquid trough a filter

7) Filtration is used on:

is used on liquids that cannot be heated and air in hospitals