Detection of oprD2 and metallo-β-lactamase genes in imipenem-resistant Pseudomonas aeruginosa in hospital

AIM: To investigate the molecular epidemiology of metallo-β-lactamases gene and oprD2 gene in imipenem-resistant Pseudomonas aeruginosa(IRPA) isolated from The First Municipal People's Hospital of Guangzhou.METHODS: Biomerieux VITEK-2 system was used to identify Pseudomonas aeruginosa and its drug susceptibility.The metallo-β-lactamase of imipenem-resistant Pseudomonas aeruginosa was measured by double disk synergy test.The metallo-β-lactamase gene and oprD2 gene in imipenem-resistant Pseudomonas aeruginosa were detected by polymerase chain reaction(PCR).RESULTS: The resistance rate of clinically-isolated 157 strains of imipenem-resistant Pseudomonas aeruginosa to the common antimicrobial agents was higher than 40%,in which 20(12.7%) were MBL-positive and 13 were IMP gene positive.The deletion of oprD2 gene was not found in 90 strains(57.3%).No VIM gene was observed.IMP gene positive with oprD2 gene deletion was found in 10 strains of imipenem-resistant Pseudomonas aeruginosa.CONCLUSION: IMP is the most prevalent MBL genotype in our hospital.The strains with IMP gene positive and oprD2 gene deletion are important characteristics of IRPA.