Analysis of genotype of metallo-?-lactamases produced by carbapenem-resistant Pseudomonas aeruginosa in pediatric patients / 中华检验医学杂志

ABSTRACT

Objective To investigate the genotype of metallo-?-lactamases (MBL) produced by carbapenem resistant Pseudomonas aeruginosa in pediatric patients.Methods 59 strains of resistance to imipenem or meropenem were collected from December 2003 to November 2005 in Beijing children's hospital.Isolates were further evaluated for MBL production by two screening methods.MBL Etest strips were used to screen the phenotype of MBL production.Molecular screening for blaVIM,blaIMP,blaSPM and blaGIM was carried out using primers targeting the conserved regions of the MBL genes.The PCR fragments obtained with integron primers were sequenced on both strands.The nucleotide sequences were compared with sequences available over the Internet.Results Of the 59 carbapenem resistant Pseudomonas aeruginosa included in this study,29 (49.2%)were MBL positive using Etest methods,and 39 (66.1%) of these tested positive for MBL genes by PCR.35 (89.7%) were positive for blaIMP genes and 4 (10.3%) were positive for blaVIM genes.All isolates were negative for SPM and GIM DNA sequencing revealed that the IMP-1 was detected in 35 IMP-producing isolates,and VIM-2 was detected in 4 VIM-producing isolates.Conclusions This study has demonstrated that MBL-producing strains in pediatric are more common than in adult.IMP-1-producing strains are the main in pediatric,and VIM-2-producing strains concurred.The production of MBL is one of the important reasons of carbapenem resistant Pseudomonas aeruginosa in pediatric.It is very important to monitor the production of MBL.