Analysis of genotypes and antimicrobial resistance of metallo-betalactamase-producing Pseudomonas aeruginosa

Objective To study the genotypes and antimicrobial resistance of metallo-beta-lactamase-producing Pseudomonas aeruginosa isolated from clinical hospitals in an area.Methods The genes of metallo-beta-lactamase were detected by polymerase chain reaction(PCR) in 100 imipenem and/or ceftazidime-resistant strains of Pseudomonas aeruginosa isolated from 3 hospitals from August,2002 to June,2007,and the minimum inhibitory concentration of 10 kinds of antimicrobial agents were determined by agar dilution method in the metallo-beta-lactamase-producing strains.Results Nine strains produced metallo-beta-lactamases,3 of which were positive in PCR analysis with blaIMP-1 primers,and 6 were blaVIM and identified as VIM-2 by DNA sequence.All the metallo-beta-lactamase-producing strains were resistant to cefoperazone,cefepime,imipenem,sulfamethoxazole-trimethoprim,partly resistant to amikacin and ciprofloxacin.Conclusion The main genotypes of metallo-beta-lactamase in epidemic strains of Pseudomonas aeruginosa were VIM-2 and IMP-1,these strains had strong drug-resistance,it is important to choose antimicrobial agents according to antimicrobial susceptibility test.