Control Methodologies for Sterilization and Disinfection

Question 1

What is sterilization

Answer 1

Total destruction of all microbes, including bacterial spores, mycobacteria, naked capsid, viruses, and fungi

Question 2

How is sterilization achieved?

Answer 2

Achieved by dry or wet head, certain gases, and certain chemicals

Question 3

What is autoclaving

Answer 3

use of moist high heat for at least 15 minutes

Question 4

Rate of killing organisms is affected by

Answer 4

size of autoclave
temperature and time
steam flow rate
location of material in the chamber
density and size of load

Question 5

How do you do a routine check of autoclave

Answer 5

spore test

error in sterilization process= spores germinate and grow

Question 6

What is dry heat treatment

Answer 6

exposure to 160 degrees for 2 hours or 1 hour

ultraviolent radiation sterilizes by damaging DNA

Ionizing radiation sterilizes by knocking off electrons from biomolecues

Question 7

What factors affect antimicrobiral activity

Answer 7

population size (load)
population composition

Question 8

True/false: Larger microbial populations take faster to kill than smaller populations

Answer 8

FALSE: larger population take longer to kill than smaller populations

Question 9

True/false: microorganisms differ markedly in their sensitivity to antimicrobial agents

Answer 9

true

Question 10

What is a vegetative cell

Answer 10

active form of bacterial cells

metabolically active but NOT undergoing cell division

Question 11

What is a endospore

Answer 11

form form of a cell

Allows for survival of adverse conditions but does not allow the cell to grow or reproduce

Question 12

Does germicide kill endospore

Answer 12

Germicide kills pathogens and many nonpathogens but not necessarily endospores

Question 13

What is germicide effective against

Answer 13

bactercides, sporicide, fungicides, algicides, and viricides

Question 14

bacteriostatic and fungistatic agents

Answer 14

inhibits growth

not as harmful to microbes as -cides

Question 15

what does bacteriostatic solution do

Answer 15

prevent the growth of bacteria on tissues or on objects in the environment

Question 16

What is disinfection

Answer 16

use of physical or chemical methods to destroy MOST microorganisms

Question 17

levels of disinfection

Answer 17

High
Intermediate
Low

Question 18

What is high-level disinfection

Answer 18

usually emulates efficiency of sterilization

Question 19

What is intermediate-level disinfection

Answer 19

bacterial spores can survive

used to clean surfaces or instruments under conditions where contamination with bacterial spores is not likely

Question 20

Low- level disinfection

Answer 20

kills most vegetative bacteria and lipid-enveloped viruses

Question 21

What is low-level disinfection used for

Answer 21

disinfect noncritical instruments including stethoscopes

Question 22

Mechanisms of harm of disinfections

Answer 22

protein denaturation
membrane disruption
nucleic acid damage
inhibition of metabolism
DNA interference

Question 23

What are phenols and phenolics

Answer 23

denature proteins and disrupt lipidic membranes

not effective against spores at room temp and has poor activity against naked capsid viruses

Question 24

What are phenolic compounds active against

Answer 24

myobacteria

Question 25

Chlorhexidine

Answer 25

used as a hand and skin antiseptic

broad spectrum of action: binds to tissues and has persistent antibacterial activity

Question 26

what does chlorhexidine reduce

Answer 26

gingival inflammation, plaque, and bleeding

Question 27

What does chlorhexidine inhibit

Answer 27

sugar transport in streptococci
amino acid uptake and catabolism in S. sanguinis
P. gingivalis protease
Membrane functions, including ATP synthase and maintenance of ion gradients in streptococci
binding of plaque-forming bacteria