Sterilization and Disinfection

Question 1

Antisepsis

Answer 1

process involving destruction or inhibition of microorganisms in living tissue thereby liming or preventing harmful effects of infection

Question 2

Antiseptic

Answer 2

typically a chemical agent applied to living tissue to kill microbes
Note: not all disinfectants are antiseptics since they must not be so harsh that it damages living tissue
Less toxic than disinfectants used on inanimate objects
Lower toxicity= antiseptics less active in destruction of normal and pathogenic flora present

Question 3

Autoclave

Answer 3

high pressure device used to allow application of moist heat above normal atm BP of water

Question 4

Biocidal

Answer 4

active substances and preps which serve to repel, render harmless or destroy chemically or biologically harmful organisms

Question 5

Biocide

Answer 5

substance or chemical that kills biological organisms

Question 6

Decontamination

Answer 6

killing of organisms or removal of contamination after sue, w/ no quantitative implication, generally referring to procedures for making items safe before disposal

Question 7

Disinfectant

Answer 7

germicide that inactivates virtually all recognized pathogenic microorganisms but not necessarily all microbial forms, may not be effective against bacterial spores

Question 8

Disinfection

Answer 8

procedure of treatment that eliminates many or all pathogenic microorganisms w/ exception of bacterial spores

Question 9

Germicide

Answer 9

agent that destroys microorganisms, particularly pathogenic microorganisms

Question 10

Sanitization

Answer 10

process of reducing microbial contamination to an acceptable “safe” level
process of cleaning objects w/o necessarily going through sterilization

Question 11

Steam Sterilization

Answer 11

autoclave, process of sterilization by use of heated steam under pressure to kill vegetative microbes and directly exposed spores
Common temp. and pressure for effectiveness: 121C (250F) at 15psi over 15min
special cases may require variation of steam temp and pressure used

Question 12

Sterilization

Answer 12

complete elimination or destruction of all forms of life by a chemical or physical mean (absolute not relative term)

Question 13

Sterile

Answer 13

free of all microbes including viruses, bacterial spores, parasitic cysts and eggs

Question 14

Asepsis

Answer 14

goal for surgical protocols (elimination of infection, rather than complete sterility)

Question 15

Disinfection

Answer 15

process which eliminates most (or all) disease causing microorganisms

Question 16

Biocides or germicides

Answer 16

kill microbes on various surfaces

Question 17

Antiseptics

Answer 17

disinfectants used on body surface (skin) only

Question 18

Bacteriocidal

Answer 18

substance or process that kills bacterial cells

Question 19

Bacteriostatic

Answer 19

substance or process that inhibits growth of bacterial cells, does not necessarily kill them

Question 20

Destroys Cytoplasmic Membrane

Answer 20

biguanides, phenolics, quats, alcohols

Question 21

Destroys Proteins

Answer 21

alcohols, aldehydes, halogen, metals, ozone, peroxygens, phenolics

Question 22

Destroys DNA

Answer 22

ethylene oxide, aldehydes, 10% bleach

Question 23

Alcohols

Answer 23

rapidly bactericidal against vegetative bacterial cells, not effective against endospores, naked viruses, activated by coagulating enzymes and other essential proteins
damages lipid membranes, 70% aq solutions works best, water helps move ethanol across cell membrane

Question 24

Aldehydes

Answer 24

inactivates proteins and nucleic acids, 2% alkaline glutaraldehyde widely used to treat heat sensitive medical items, 10hrs immersion kills all microbial life, endospores and viruses
toxic

Question 25

Ethylene Oxide

Answer 25

gas, reacts w/ proteins, kills microbes, endospores, viruses, penetrates well into variety of materials (useful for completely sterilizing implants, pacemakers, electrical equipment, disposables
use usually limited to manufacturing or associated specialized dedicated sterilization facilities
mutagenic, extremely toxic, very expensive, requires containment facility (space w/ special ventilation)

Question 26

Halogens

Answer 26

Chlorine: 10% bleach cheap, effective for disinfecting surfaces, destroys all types of microbes, viruses
irritating to skin and mucus membranes, unstable, must be replaced daily; inhibited by organic matter
Iodine: linked to carrier molecules (iodophores), this way not as irritating to skin

Question 27

Hydrogen peroxide (H2O2)

Answer 27

cells that use aerobic metabolism can inactivate H2O2 through catalase, activity low in microbes, useful as disinfectant

Question 28

Phenol Compounds

Answer 28

destroy cytoplasmic membranes of microbes, denatures proteins, wide range of activity including mycobacterium
irritating to skin, unpleasant odor

Question 29

Quaternary Ammonium Compounds (Quats)

Answer 29

cationic detergents (attracted to (-) charged cell surfaces of many microbes, reacts w/ cell membranes)
reduces surface tension of liquids making them efficient in washing away organic material

Question 30

Selection for Antimicrobial procedure

Answer 30

microorganism type
potential risk of infection
environmental conditions