CTX-M-5, a novel cefotaxime-hydrolyzing beta-lactamase from an outbreak of Salmonella typhimurium in Latvia.

ABSTRACT: At a children's hospital in Riga, Latvia, isolates identified as Salmonella typhimurium were found to be resistant to expanded-spectrum cephalosporins. Two of the resistant strains were analyzed for the mechanism of cephalosporin resistance. Isoelectric focusing revealed a common beta-lactamase with a pI of 8.8. In addition, one of the strains produced a pI 7.6 beta-lactamase. A transconjugant producing only the pI 7.6 enzyme was susceptible to expanded-spectrum cephalosporins; therefore, this enzyme was most likely SHV-1. Transformants producing only the pI 8.8 beta-lactamase were resistant to cefotaxime and aztreonam but were susceptible or intermediate to ceftazidime. A substrate profile determined spectrophotometrically with purified enzyme revealed potent activity against cefotaxime,

SUBMITTER: Bradford PA 

PROVIDER: S-EPMC105719 | biostudies-literature | 1998 Aug

REPOSITORIES: biostudies-literature