Question

2 List 7 factors that affect effectiveness of a disinfectant 3. List 5 factors that influence the size of the zone of inhibition on the antibiotic disk plate.

Answer 1

Question 02:

Answer:

7 factors which affect the effectiveness of a disinfectant are:

1. Number and Location of Microorganisms.
2. Innate Resistance of Microorganisms.
3. Concentration and Potency of Disinfectants.
4. Physical and Chemical Factors (temperature, pH, relative humidity, and water hardness).
5. Organic and Inorganic Matter.
6. Duration of Exposure.
7. Biofilms (these are a thick layer of extracellular mass which can cover and protect micro-organisms).

Question 03:

Answer:
Five factors that influence the size of the zone of inhibition on the antibiotic disk plate are:

1. Inoculum density.
2. Timing of disc application.
3. The temperature of incubation and Incubation time.
4. Size of the plate, depth of agar medium, and spacing of the antibiotic discs.
5. The potency of the antibiotic discs.   Another factor - Composition of the medium.