CTX-M from community-acquired urinary tract infections in Algeria

Thirty-eight Enterobacteriaceae isolates including seventeen Klebsiella pneumoniae, thirteen Escherichia coli and eight Enterobacter cloacae resistant to broad-spectrum cephalosporins were recovered from community-acquired urinary-tract infections at four private-laboratories in Bejaia, Algeria, between March 2007 and May 2009. Antimicrobial susceptibility testing of these isolates to 23 antimicrobials was performed by disk diffusion according to the recommendations of the Antibiogram Committee of the French Society for Microbiology. Results of antimicrobial testing showed that, all isolates are resistant to ticarcillin, piperacillin, cefotaxime, Cefpirome. Decreased susceptibility was observed against others agents. They remained susceptible toward imipenem. Genes encoding extended-spectrum-beta-lactamases (ESBL) and plasmid-mediated quinolone resistance (PMQR) were characterized by PCR and sequencing. All isolates were found to produce CTX-M-type ESBL: CTX-M-15 was identified in thirty-three isolates and CTX-M-3 in five isolates. In addition, nine isolates were positive for the qnr gene, including 5 of qnrB1 and 4 of qnrS1 . Ten isolates were found to produce aac(6’)lb-cr resistance determinants. Molecular typing showed a clonal relatedness between isolates.