Basic Bacteriology-Sterilization, Disnfection, and Containment

Question 1

What is this:

use of physical or chemical agent to destroy all microbial forms, including spores

Answer 1

sterilization

Question 2

What is this:
use of physical or chemical agents to destroy most microbial forms; bacterial spores or other relatively resistant organisms may remain viable

Answer 2

Disinfection

Question 3

What is this:

use of chemical agents on skin or other living tissue to inhibit or eliminate microbes; no sporicidal action is implied

Answer 3

Antisepsis

Question 4

What is this:

a general term describing a chemical agent, usually with a broad spectrum, that inactivates microbes

Answer 4

biocide

Question 5

What are the factors influencing disinfectent potency?

Answer 5

• concentration
• time
• pH
• temperature
• presence of extraneous materials
• microorganism

Question 6

What is the relationship between concentration and time required to kill?

Answer 6

inverse correlation

Question 7

pH can dramatically influence potency. T or F?

Answer 7

T

Question 8

Kill rate (increases/decreases) with temperature

Answer 8

increases

Question 9

What can extraneous materials do to disinfectants?

Answer 9

bind or inactive the disinfectant

Question 10

WHat is the most resistant pathogen to antiseptics and disinfectants? What is the least resistant?

Answer 10

prions

Lipid enveloped viruses

Question 11

What is the mechanism of action of the antiseptic/disinfectant Ethylene Oxide and Aldehydes?

Answer 11

alkylate and cross-ink macromolecules, e.g. protein, DNA, or RNA

Question 12

What is and what kind of product is formaldehyde?

Answer 12

used for environmental decontamination; used in gaseous form or dissolved in water. It is an aldehyde

Question 13

What is and what kind of product is Glutaraldehyde?

Answer 13

a chemical sterilizer used on equipment and it is an aldehyde

Question 14

What is Ethylene Oxide?

Answer 14

a gaseous sterilization of heat sensitive materials

Question 15

What are three oxidizing agents?

Answer 15

ozone
hydrogen peroxide
peracetic acid

Question 16

What do oxidizing agents do?

Answer 16

they oxidize proteins; DNA breakage

Question 17

What does ozone do?

Answer 17

disinfects air systems

Question 18

What does hydrogen peroxide do?

Answer 18

cleanses wounds, disinfects implants, prostheses

Question 19

What does peracetic acid do?

Answer 19

chemical sterilant

Question 20

What is the mechanism of action of halogens?

Answer 20

Oxidizes proteins

Question 21

What are 2 halogens?

Answer 21

Iodine

Chlorine

Question 22

What does Iodine do?

Answer 22

skin disinfection

Question 23

What does chlorine do?

Answer 23

chemical decontamination

Question 24

What is the mechanism of action of phenolic compounds?

Answer 24

Disrupt lipid containing membranes; denature proteins

Question 25

What are 2 phenolic compounds?

Answer 25

Chlorhexidine | Triclosan

Question 26

What does Chlorhexidine do?

Answer 26

skin disinfection

Question 27

What does Triclosan do?

Answer 27

antibacterial soaps; innumerable other uses

Question 28

What is the mechanism of action of quaternary ammonium compounds?

Answer 28

surfactant-amphoteric properties disrupt membranes

Question 29

What is an example of a quaternanry ammonium compound?

Answer 29

Benzalkonium chloride

Question 30

What does Benzalkonium chloride do?

Answer 30

skin disinfection; hard surface cleaning (lysol is an example)

Question 31

What is the mechanism of action of alcohols?

Answer 31

denature proteins

Question 32

What is an example of an alcohol?

Answer 32

isopropyl alcohol

Question 33

What does isopropryl alcohol do?

Answer 33

Skin decontamination; disinfection (i.e thermometers)

Question 34

How can you get intrinisc resistance to antiseptics and disinfectants?

Answer 34

physiological adaptation -biofilms | variable among microbes

Question 35

How can you get acquired resistance to antiseptics an disinfectants?

Answer 35

inativation of agent efflux of agent decreased uptak

Question 36

What kind of agents can get inactivated by pathogens?

Answer 36

chlorhexidine formaldehyde mercurials

Question 37

What kind of agents get inactivated by efflux of agent?

Answer 37

Quaternary ammonium compounds | Chlorhexidine

Question 38

What kind of agents get inactived by decreased uptake?

Answer 38

silver compounds

Question 39

What temperature is required to kill most pathogenic bacteria?

Answer 39

60 degrees celcius

Question 40

What temperature is required to kill vegetative forms of all bacteria and fungi?

Answer 40

80 degrees celcius

Question 41

What temperature is required to kill spores of pathogens?

Answer 41

100 degrees celcius

Question 42

What temperature is required to kill all bacterial spores?

Answer 42

120 degrees celcius

Question 43

What temperature is required to pasteurize?

Answer 43

72 degrees celcius

Question 44

What temperature is required to boil?

Answer 44

100 degrees celcius

Question 45

What temperatures is required to autoclave (stem under pressure)?

Answer 45

120 degrees celcius

Question 46

What temperature is required to dry heat?

Answer 46

180 degrees celcius

Question 47

What is the hottest way to kill pathogens?

Answer 47

incineration

Question 48

What are 2 physical agents to kill or remove microbes?

Answer 48

radiation | filtration

Question 49

What are the 2 types of radiation?

Answer 49

UV irradiation | Ionizing radiation

Question 50

What are examples of UV irradiation?

Answer 50

Sunlight, UV lights

Question 51

When should you use UV irradiation?

Answer 51

control of airbone or surface contamination (poor to no penetration of solids)

Question 52

What are examples of Ionizing radiation?

Answer 52

X-ray and gamma emitters

Question 53

When should you use Ionizing radiation?

Answer 53

sterilization of small heat-sensitive articles

Question 54

What does filtration do?

Answer 54

filter sterilization of heat-labile liquids (no removal of viruses or other small forms from liquids) HEPA filtration of air (quite effective, even for viruses)

Question 55

What biosafety level is this: work involves well-characterized agents not known to consistently cause disease in human adults Basic level of containment (work conducted on open benches) Relies on standard microbiological practices No special barriers Lab personnel have specific training or are supervied by scientist with training

Answer 55

Biosafety level I (BSL-1)

Question 56

What biosafety level is this: involves broad spectrum of indigenous moderate-risk agents (Hep B, HIV, Solmonellae) Lab hazard is associated with percutaneous exposure, ingestion, or mucous membrane exposure Lab personnel have spec training are are directed by competent scientists. Access to lab is limited Biohazard signs are up Extreme precautions taken with sharps Use biological safety cabinet

Answer 56

Biosafety Level 2 (BSL-2)

Question 57

What biosafety level is this: - indigenous or exotic agents w/ potential for aerosal transmission; disease have serous or lethal consequences - Laboratory personnel have spec training and are supervised by scientists who are experienced in working with these agents - all procedures involving manipulation of infectious agents are done in a biosafety cabinet or other physical containment devices - the laboratory has special engineering and design features, including security

Answer 57

Biosafety Level 3 (BSL-3)

Question 58

What biosafety level is this: Work done w/ dangerous and exotic agents that pose a high individua risk of aerosol-transmitted laboratory infection and life-threatening disease -laboratory staff have specific and extensive training -access to laboratory is highly controlled - facility is isolated and has special engineering and design features to prevent spread outside facility -All activity confined to class III biological safety cabinets (fully self contained) or class II cabinets with personnel using positive pressure suits ventilated by a life support system.

Answer 58

Biosafety level 4 (BSL-4)