Detection and homology analysis on metallo-β-lactamases gene in clinically isolated gram-negative bacteria / 中国感染控制杂志

ABSTRACT

Objective To investigate the detection of IMP andVIM metallo-β-lactamases (MβLs)genes in clinically iso-lated gram-negative bacteria as well as bacterial resistance toβ-lactam antimicrobial agents.Methods 113 clinically isolated bacteria were performed antimicrobial susceptibility testing by Kirby-Bauer method ,drug-resistant genes IMP and VIM were detected by polymerase chain reaction (PCR),PCR products were sequenced and aligned with BLAST software. Results VIM gene was detected in 1 Pseudomonas fluorescens strain ,IMP gene was detected in 15 strains ,they were Klebsiella pneumoniae (n=6),Acinetobacter baumannii (n=3),Escherichia coli (n=2),Ralstonia picket-tii (n=1),Pseudomonas aeruginosa (n=1 ),Citrobacter amalonaticua (n=1 ),and Enterobacter cloacae (n=1 ). BLAST results showed that VIM gene was VIM-2 subtype,similarity with gene bank was 99%;all IMP genes were IMP-1 subtype,which were highly homologous ,similarity was 98%-99%.Resistant rates of IMP positive strains to ceftriaxone,cefotaxime,cefoxitin,aztreonam and imipenem were all significantly higher than negative strains (all P <0.05).Conclusion IMP genes of different strains are highly homologous,all are IMP-1 type,indi-cating that IMP genes are highly transmissible and can spread among different species of bacteria.IMP genes are related with resistance ofβ-lactam antimicrobial agents.