A total of 2440 Escherichia coli strains isolated in 2003 at the Hospital de la Santa Creu i Sant Pau were evaluated for the presence of extended-spectrum β-lactamases. Two different nucleotide sequences that encode the same β-lactamase, CTX-M-14, were detected when the blaCTX-M-14-genes of 35 E. coli isolates were analysed. Thirty-two of the 35 had the previously described sequence of the blaCTX-M-14 (AF252622), named bla CTX-M-14a, and the remaining three isolates showed a nucleotide sequence identical to that of the blaCTX-M-9 gene except for one nucleotide, named blaCTX-M-14b. Characterisation of the regions surrounding the blaCTX-M-14a showed the ISEcp1 and the IS903 upstream and downstream, respectively, of the bla gene, whereas the regions surrounding the blaCTX-M-14b contained the genetic environment described for the blaCTX-M-9 gene, the In60. Characterisation by hybridisation showed that the blaCTX-M-14a was present in IncK plasmids, whereas the blaCTX-M-14b was found in the HI2 Inc group. The CTX-M-14 ESBL in E. coli isolates is the result of the convergence of two different genes. © 2007 Federation of European Microbiological Societies.
|Journal||FEMS Microbiology Letters|
|Publication status||Published - 1 Aug 2007|
- Escherichia coli