CTX-M-1, CTX-M-3, and CTX-M-14 beta-lactamases from Enterobacteriaceae isolated in France

Abstract

Six clinical CTX-M-producing isolates of the family Enterobacteriaceae were detected between 1999 and 2000 in different French hospitals. Two strains produced CTX-M-1 and CTX-M-3 and four strains produced CTX-M-14, a mutant Ala-231-->Val of CTX-M-9. A putative transposable element, ISEcp-1, was located 43 bp upstream of all the bla(CTX-M) genes. Two CTX-M-14-encoding plasmids exhibited similar restriction patterns. The CTX-M-1- and CTX-M-3-encoding plasmids were related to the CTX-M-1- and CTX-M-3-encoding plasmids previously reported in 1990 in France and in 1998 in Poland, respectively.

FIG. 1.

(A) Agarose (0.7%) electrophoresis of plasmid DNA from CTX-M-producing E. coli transconjugants. (B) Agarose (0.7%) electrophoresis of HpaI-restricted plasmid DNA from CTX-M-producing E. coli transconjugants. Lanes: 1, molecular size marker; 2, CTX-M-1-encoding plasmid pCF-2; 3, CTX-M-1-encoding plasmid pMEN (2); 4, CTX-M-3-encoding plasmid pVer-1; 5, CTX-M-3-encoding plasmid A1 (20); 6, CTX-M-14-encoding plasmid pCF-1; 7, CTX-M-14-encoding plasmid pMnt-1; 8, CTX-M-14-encoding plasmid pRoa-1.