Lecture 3 Sterilisation, disinfection, filtration

Question 1

Define disinfection

Answer 1

Reduces the number of pathogens (but not spores) so they pose no threat of disease

Question 2

Defined Sterilisation

Answer 2

A physical or chemical process that completely destroys or removes microbes, including spores

Question 3

What is sterilisation used for?

Answer 3

Used for surgical instruments, syringes

Question 4

What are some methods used for sterilisation?

Answer 4

heat, irradiation, filtration

Question 5

What are disinfection used for?

Answer 5

Chemical agents used on inanimate (surfaces) or animate (living tissue)

Question 6

what are some methods used for disinfection?

Answer 6

sodium hypochlorite, iodine, alcohols

Question 7

what is the less resistant micro-organism?

Answer 7

Envelope viruses
Non-envelope viruses
Gram positive bacteria

Question 8

What are the most resistant micro-organism?

Answer 8

Prions
Bacterial endospores
Mycobacterium

Question 9

what are the types of physical control of micro-organism?

Answer 9

• Physcial (thermal) → Heat - dry or moist

- Physical (non-thermal) → Radiation — gamma ray, UV OR Filtrations

Question 10

what are the types of Chemical control of micro-organism?

Answer 10

Gasses or liquids

Question 11

What are the types of Physcial (thermal) control?

Answer 11

Dry heat using Hot air ovens and Incineration

Moist heat using boiling water, Pasteurisation of liquid, Tyndallisation, and Autoclaves

Question 12

What are the types of Physcial (non-thermal) control?

Answer 12

Radiation

Filtration

Question 13

What are the types of liquid used in chemical control?

Answer 13

Biguanides
Chlorine
Iodine 
Alcohols
hydrogen peroxide
Aldehydes

Question 14

What are the types of gaseous used in chemical control?

Answer 14

Ethylene oxide (EO)