Chapter 8

Front 1

Sterilization

Back 1

process by which all living cells, spores, and aceullular entities are either destroyed or removed from an object or habitat.

Front 2

disinfection

Back 2

killing, inhibition, or removal of microbes that may cause disease, reduction of population and destruction of potential pathogens

Front 3

disinfectants

Back 3

agents usually chemical used to carry out disinfection and normally used only on inanimate objects, does not necessarily sterilize

Front 4

sanitization

Back 4

the microbial population is reduced to levels that are considered safe by public health standards.

Front 5

antisepsis

Back 5

destruction or inhibition of microbes on living tissue, it is the prevention of infection or sepsis

Front 6

antiseptics

Back 6

chemical agents applied to tissue to prevent infection by killing or inhibiting pathogen growth

Front 7

Chemotherapy

Back 7

use of chemical agents to kill or inhibit the growth of microbes within host tissue

Front 8

-cide means

Back 8

kills pathogens, but not neceassarily endospores

Front 9

-static

Back 9

do not kill but rather prevent growth, if remove growth will resume

Front 10

D value

Back 10

decimal reduction time, measure of an agents killing efficiency, time required to kill 90% of the microbes or spores in a sample

Front 11

Microbial death

Back 11

must be persister cells or dead, usually occurs exponentially, not killed instantly

Front 12

persister cells are reffered as

Back 12

VBNC

Front 13

Population size effect antimicrobial agent activity

Back 13

larger populations take longer to kill than smaller populations

Front 14

Population compostion affect on antimicrobial agent activity

Back 14

microbes differ markedly in their sensitivity to antimicrobial agents

Front 15

How concentration effects antimicrobial agent activity

Back 15

usually higher concentrations kill more rapidly,

Front 16

Other conditions that affect antimicrobical activity

Back 16

duration of exposure, temperature, and local enviorment

Front 17

depth filters

Back 17

fibrous or granular materials that have been bonded into a thick layer filled with channels of small diameter, microbes removed by entrapment or adsorption

Front 18

membrane filters

Back 18

porous membranes with defined pore sizes that removes microbes by screening

Front 19

filtration

Back 19

reduces microbial population or sterilizes solutions of heat sensitive materials by removing microbes, and used to reduce air microbes

Front 20

High-effiencey particulate air filters

Back 20

HEPA filters are used in laminar flow biological safety cabinets

Front 21

Moist Heat

Back 21

degrades nucelic acids, denatures proteins and disrupts membranes, destroys viruses fungi and bacteria

Front 22

boiling

Back 22

does not sterilize and will not destroy spores

Front 23

Steam Sterilization

Back 23

above 100 degrees C and requires pressure ex(autoclave)

Front 24

steam strerilization is effective against

Back 24

all types of microbes including endospores

Front 25

The control in autclaving is

Back 25

strips with Geobacillus stearothermophilus

Front 26

Pasteurization

Back 26

controlled heating at temperatures below boiling, does not sterilize but does kill pathogens present and slows spoilage by reducing microbes

Front 27

pasteruization is used for

Back 27

milk beer and other beverages,

Front 28

dry heat sterilization

Back 28

is less effective than moist heat, requires higher temperatures and longer times (160-170C, for 2-3hrs)

Front 29

how is dry heat effective

Back 29

it oxidizes cell constitutents and denatures proteins

Front 30

Dry heat incineration

Back 30

bench top incinerators are used to sterilize inoculating loops used in micro labs

Front 31

UV Radiation

Back 31

has a wavelength of 260nm is lethal and causes thymine dimers in DNA which prevents repliation and transcription

Front 32

UV is limited to

Back 32

surface sterilization because it does not penetrate glass, dirt films, water and other substances, but has been used for water treatment

Front 33

Ionizing radiation

Back 33

gamma radiation that penetrates deep into objects, and destroys bac. endospores but not always viruses

Front 34

ionizing radiation is used for

Back 34

sterilization and pasteurization of antibiotics hormones, sutures, food and plastic disposables

Front 35

Disinfectants effectivness

Back 35

must be effective against a wide variety of microbes and at low concentrations, and iin organic matter, and be stable in storage

Front 36

Tricolosan

Back 36

overuse has selected for resistnat bacteria and possible antibiotic resistance

Front 37

Phenolics

Back 37

used in lab and hospitals, denatures proteins and disrupts cell membranes, tuberculocidal and effective in organic material, long lasting but has a smell and can cause skin irratation

Front 38

Alcohols

Back 38

ethanol and ispropanol, not sporicidal, inactivates some viruses, and denatures proteins and dissolves some membrane lipids

Front 39

Iodine

Back 39

used as skin antiseptic, oxidizes and iodinates proteins, kills spores at high concentrations, may cause skin damage and staining and allerigies

Front 40

Iodophore

Back 40

iodine complexed with organic matter, can minimize skin burns when released slowly

Front 41

Chlorine

Back 41

oxidizer, disinfects water supplies and pools used in food and households, destroys vegetative cells, and when in gas form is sporicidal

Front 42

Chlorine can

Back 42

react with organic matter to form carcinogenic compounds

Front 43

Heavy Metals

Back 43

merucury, silver, arsenic, zinc, copper, effective but toxic, combines with and inactivates proteins

Front 44

Quaternary Ammonium Compounds

Back 44

detergents that have antimicrobial activity and are disinfectants, ex. (amphipathic cleansing agents i.e. soap)

Front 45

cationic detergents

Back 45

are effective disinfectants, kills most bacteria but not TB or endospores, safe and easy to use inactivated by hard water and soap

Front 46

Aldehydes

Back 46

highly reactive molecules, sporiocidal and can be used as a chemical sterilant, combines with and inactivates nucleic acids and proteins

Front 47

Commonly used aldehyde agents

Back 47

formaldehyde and glutaraldehyde

Front 48

Sterilizing gases

Back 48

used to treat heat sensitive materials, microbicidal and sporicidal,

Front 49

Ethlene oxide

Back 49

carried out in equipment resembling an autoclave, very strong, penetrates materials

Front 50

Betapropiolactone

Back 50

does not penetrate materials as well and can be carinogenic, used to sterilize vaccines and blood products and inactivates after several hours

Front 51

Vaporized hydrogen peroxide

Back 51

decontaminates biology safety cabinets and oxygen rooms, sterilizing vapor that breaks down to water and oxygen does not damage most nonliving materials

Front 52

EPA

Back 52

regulates disinfectants

Front 53

FDA

Back 53

regulates agents used on humans and animals

Front 54

phenol-coefficient test

Back 54

a potency of disinfectant is compared with that of phenol, dilutions and then incubation and observation for growth, may be misleading

Front 55

the higher the phenol-coefficient value

Back 55

the more effective the disinefectant under the test conditions

Front 56

Use dilution test

Back 56

determines rate at which selected bacteria are destroyed by various chemical agents

Front 57

Normal in-use testing

Back 57

tseting done using conditions that approximates normal use of disinfectants

Front 58

Biological control of microbes

Back 58

toxin-mediated killing using bacteriocins, predation, viral-mediated lysis using pathogen specific bacteriophage lysins