Control of Microbial Growth

Question 1

Define biocide

Answer 1

Antimicrobial agents that control microorganisms

Question 2

Outline the difference between sterilisation and disinfection

Answer 2

Sterilisation kills all microorganisms whereas disinfection remove pathogenic organisms

Question 3

What is the main difference between antisepsis and disinfection

Answer 3

Antisepsis is applied to living tissue whereas disinfection is applied to inanimate objects

Question 4

How is sanitisation measured

Answer 4

reduction of microorganisms to a point that is ok for PH standards

Question 5

Outline the difference between -cidal and -static agents

Answer 5

-cidal - kill
-static - inhibit growth

Question 6

Give an example of air filtration and liquid filtration in terms of physical removal methods

Answer 6

Membrane filters - defined pore sizes
Surgical masks

Question 7

Give four methods of heat treatment in terms of physical removal methods

Answer 7

Moist heat - boiling
Steam sterilisation - use of an autoclave
Pasteurisation
Dry heat

Question 8

Give 1 example of ionising and non-ionising radiation in terms of physical removal methods

Answer 8

UV
Gamma

Question 9

Give 4 examples of chemical control agents

Answer 9

Phenolics
Alcohol
Sterilising gases
Halogens

Question 10

Give 3 conditions influencing the effectiveness of antimicrobial agent activity

Answer 10

Population size and composition
Local environment
Contact time