A plasmid-mediated beta-lactamase conferring resistance to cefotaxime in a Salmonella typhimurium clone found in St Petersburg, Russia

Abstract
Four clinical and two environmental isolates of cefotaxime-resistant Salmonella typhimurium strains collected in St Petersburg, Russia, were studied. Molecular typing demonstrated that they constituted a single clone. The isolates expressed a cefotaxime-hydrolysing beta-lactamase with a pl of 8.4. The enzyme was encoded by a 12 kb plasmid which did not hybridize with TEM, SHV or ampC probes.