Detection and genotypes of metallo-β-lactamase-producing Pseudomonas aeruginosa

Objective To investigate the genotypes, antibiotic susceptibility and homology of metallo-β -lactamase-producing P. aeruginosa isolated from our hospital.Methods 2-mercaptopropanic acid disc or EDTA synergy test was used to screen metallo-β-lactamase producing and imipenem-resistant P. aeruginosa. PCR was used to identify metallo-β-lactamase genotypes. The homology of these strains was analyzed by pulsed-field gel electrophoresis (PFGE).Results A total of 31 P. aeruginosa isolates were identified, 5 of which produced metallo-β-lactamase as tested by 2-mercaptopropanic acid-disc or EDTA synergy test. Four strains producing IMP-9 were confirmed by PCR and sequencing. PFGE revealed these 4 strains isolated from Department of Neurology belonged to the same clone.Conclusions IMP-9 metallo-β-lactamase producing P. aeruginosa strain is prevalent in our hospital. The emergence of metallo-β-lactamase producing P. aeruginosa will be a serious problem.