NILIMA LANKESHVVAR AND U.S. BAGDE
Abstract
The emergence of drug resistant bacteria is posing a major problem in antimicrobial therapy. A possible mechanism of resistance to ampicillin (Ap) in Shigella dysenteriae was studied. The growth of sensitive Shigella dysenteriae was completely inhibited at 100 .t.g/mL concentration of Ampicillin, while-the resistant strain tolerated even 1000 p.g/mL concentration of Ampicillin. Mechanism of resistance was found to be f3-lactamase production. P-lactamase activity was detected in resistant strain by qualitative plate test. P-lactamase specifying plasmid was analyzed by agarose gel electrophoresis. Plasmid curing was successful with 2-10% sodium dodesyl sulfate (SDS) treatment. All colonies on plate after SDS treatment were tested for drug resistance character on nutrient agar containing different concentrations of ampicillin.