(NOT IN TOPIC LIST 2021) 3. Asepsis and antisepsis Sterilisation, desinfection.

Question 1

Asepsis

Answer 1

asepsis is the equivalent of STERILISATION. Sterilisation refers to the total elimination of microbes.

Question 2

Sterilization techinques (non-chemical)

Answer 2

Boiling (kills bacteria)

Autoclave (kills everything, but prions could survive standard settings)

Pasteurization

Dry heat

Freezedrying

UV-radiation, ionising radiation

Membrane filtration (not effective for virus)

Question 3

TDP

Answer 3

Thermal death point

Lowest temp. in which all bacteria of a culture dies within 10 minutes

Question 4

TDT

Answer 4

Thermal death time

The time given in which 90% of all bacteria has been killed at a given temperature

Question 5

Difference between wet and dry heat sterilization

Answer 5

Wet heat (autoclave, boiling) causes protein denaturation
Dry heat causes oxidation

Question 6

Chemical sterilization techniques

Answer 6

ETO sterilization (toxic for humans)

Plasma sterilization

Question 7

Prion inactivation

Answer 7

1. Autoclave for 1 hour

2. Treat with 5% hypochloride solution + 1M NaOH

Question 8

Antisepsis

Answer 8

Equivalent of DISINFECTION

Question 9

Disinfectant vs. antiseptic agent

Answer 9

Disinfectant KILLS microbes, antiseptics REDUCES level of microbes. Both used on non-living surfaces

Question 10

Important desinfectants

Answer 10

Soaps/detergents
QUATS (quarternary ammonium compounds, cation detergents)
Heavy metals 
Halogens 
Alcohols 
Phenols
Aldehydes