title: Evidence for convergent evolution of CTX-M-14 ESBL in Escherichia coli and its prevalence.
abstract: 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 beta-lactamases. Two different nucleotide sequences that encode the same beta-lactamase, CTX-M-14, were detected when the bla(CTX-M-14)-genes of 35 E. coli isolates were analysed. Thirty-two of the 35 had the previously described sequence of the bla(CTX-M-14) (AF252622), named bla(CTX-M-14a), and the remaining three isolates showed a nucleotide sequence identical to that of the bla(CTX-M-9) gene except for one nucleotide, named bla(CTX-M-14b). Characterisation of the regions surrounding the bla(CTX-M-14a) showed the ISEcp1 and the IS903 upstream and downstream, respectively, of the bla gene, whereas the regions surrounding the bla(CTX-M-14b) contained the genetic environment described for the bla(CTX-M-9) gene, the In60. Characterisation by hybridisation showed that the bla(CTX-M-14a) was present in IncK plasmids, whereas the bla(CTX-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.
authors.affiliation: Servei de Microbiologia de l'Hospital de la Santa Creu i Sant Pau, Barcelona, Spain. fnavarror@santpau.es
authors.forename: Ferran
authors.initials: F
authors.lastname: Navarro
authors.forename: Rául-Jesús
authors.initials: RJ
authors.lastname: Mesa
authors.forename: Elisenda
authors.initials: E
authors.lastname: Miró
authors.forename: Laura
authors.initials: L
authors.lastname: Gómez
authors.forename: Beatriz
authors.initials: B
authors.lastname: Mirelis
authors.forename: Pere
authors.initials: P
authors.lastname: Coll
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D002876:Chromosomes, Bacterial / Q000235:genetics; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics; D023061:Gene Order; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C412613:CTX-M-9 protein, E coli; C456080:beta-lactamase CTX-M-14; D001618:beta-Lactamases