Transferable beta lactam resistance against cephalosporins in Salmonella typhimurium strains in India.

ABSTRACT

From 14 strains of S. typhimurium which were resistant to three cephalosporins (cephalexin, cefadroxil and sodium cefotaxime) the resistance plasmids were transferred to two different strains (Escherichia coli K12F-Lac-Rifr and S. typhimurium LT2). The plasmids were autotransferable and the donors as well as transconjugants showed high levels of MIC (80-320 micrograms/ml or more) against these antimicrobial agents. The resistance was demonstrated to be mediated by a 15 kilobase plasmid.