Question

The students swabbed each plate and set a filter paper disk with 10% bleach solution of differing ages on the plates for 10 minutes. The disks were removed and then the plates were incubated for 48 hours. The diameter of clearing was measured for each plate. Create a Table, with title, in the results and then interpret the results in the discussion. Notice how some areas of clearing show individual colonies. What mechanisms may allow for that growth within a zone of inhibition? Discuss in the discussion section of your lab report.

i want to know What mechanisms may allow for that growth within a zone of inhibition?

Answer 1

Zone of inhibition determines the ability of the antibiotic or disinfectant to kill the microoganisms growing at that area that causes the cells to lyse and give a clear zone. If there is a zone of inhibition, that means the bacteria is succeptible to the antibotic. If there is growth within the zone of inhibition, this means that the organism is resistant to the antibiotic used. Bleach is a disinfectant that may inhibit the growth of the organism by static method and not always cidal . Thus after a certain point of time, the static organisms may acquire resistance against the chemical used and start growing again in the area within the zone of inhibition. There are various mechanisms of resistance :

1. It may have been possible that the static organisms have taken up a strategy to take up limited amount of the antibiotic used and hence have gradually developed resistance.

2. The organsims may have altered the drug target and thus have become resistant against iit.

3. There might be certain mechanisms that may lead to the inactivation of the bleach or drug by some method within the organism.

4. There might be a possibility that there is an active mechanism of the efflux of the disinfectant from the organism that renders it growth within the clear zone.