Metallo-β-lactamase Produced in Carbapenem-resistant Pseudomonas aeruginosa

OBJECTIVE To investigate the prevalence of metallo-β-lactamase in carbapenem-resistant clinical Pseudomonas aeruginosa isolates.METHODS Sixteen strains of P.aeruginosa isolated from Tianjin General Hospital during 2005-2006 which were resistant to all tested antibiotics besides carbapenem were studied.The general PCR was adopted to amplify the resistance genes of matallo-β-lactamae.Restriction endonucleases performed restriction analysis were used to certify the type of genes of matallo-β-lactamase by different endonuclease recognition site.RESULTS Two of the 16 clinical strains of P.aeruginosa(named P02 and P16) were confirmed bearing IMP-1 metallo-β-lactamase gene detected by PCR amplification and restriction analysis.CONCLUSIONS P.aeruginosa producing IMP-1 metallo-β-lactamase is the major type in our hospital.The hydrolyzing effect of the metallo-β-lactamase is not the main machanism in these carbapenem-resistant P.aeruginosa isolates.