Question

Suggest a reason why the different antibiotics were allowed different diameters of their zones of inhibition on the table of antibiotic sensitivity.

Answer 1

answer

antibiotic sensitivity is succeptibility of bacteria tp antibiotics . it is tested using methodes such as

kirby bauer methods , stroke methodes , Etest .

a semi quantitative way based on diffusion is kirby bauer method. here small disc containing different antibiotics are dropped in different zones of the culture on agar plate , which is nutrient rich enviornment in which bacteria can grow, the antibiotic will diffuse in the area surrounding each tablet and disc of bacterial lysis will became visible. the diameter of the circlle formed is minmun inhibitory concentration.

different factors such as drug solubility , rate of drug diffusion through agar , thickness of agar medium , drug concentration impregnated in the disc.

the size of zonal inhibition is related to level of antimicrobial activity present in the sample . a larger zone of inhibition means the antimicrobial is more potent . so differentr antibiotoic act differently with each bacteria , some bacteria are resistant to the action of some antibiotics , some are affected by antibiotics.. so the diameter of their zone of inhibition also vary