Study On The Genotypes Of Metallo-β-lactamases In Pseudomonas Aeruginosa

Objective:To study the genotypes and molecular epidemiology of metallo-beta-lactamase-Producing Pseudomonas aeruginosa isolated in our hospital. Guide the clinical application of antibiotics for help,and the spread and dissemination of MBL will be prevented .Methods:The Metallo-beta-lacamase-Producing imipenem-resistant 91 Isolates were detected by Double-Disk Synergy Test in our hospital from 2006 to 2007. PCR assays for blaIMP and blaVIM were performed by use of previously published primers and amplifica tion conditions. The PCR products were sequenced and analyzed by ABI PRISM 3730 sequenator. Sequence alignments and analyses were performed online using the BLAST program (www.ncbi.nlm.nih.gov). Analyse the identification of metallo-β- lactamases with the sequence ten consistant of blaVIM-2 by DNAMAN. All datas were analyzed by WHONET 5.3 software.Result:1. The detection of Metallo-β-lactamase in PAThe are 24 isolates were Metallo-β-lacamase- Producing in imipenem-resistant Pseudomonas aerudinosa isolates from 2006 to 2008. The isolating rate is 26.4%.2. Detect genotype of the Metallo-β-lactamase- Producing isolatesIn this study , of the 24 MBL positive isolates were using phenotypic methods : 23 isolates were positive for blaVIM genes and 1 isolate was positive for blaIMP gene.Sequence alignments and analyses were performed online using the BLAST program, ten isolates were blaVIM-2 genes and only one isolate was blaIMP gene.3. Identification of metallo-β-lactamasesSequence analysis of the products obtained with the VIM primers revealed 98% identity with the sequence of the blaVIM-2 allele by DNAMAN.4. Contrast the distribution,morbidity and mortality infections by 1MBL-PA and by by non-MBL-PAInfections by MBL-carrying Pseudomonas aeruginosa (MBL-PA) is the most in the neurosurgery, and the isolating rate is 52.4% .These resulted in higher in-hospital mortality than those by non-MBL-PA (20.8% versus 11.9%).Results:P. aeruginosa-possessing MBLs in IPM-resistant isolates have constituted high propotion of nosocomial isolates.The VIM-2 gene was the most isolates.So that,we know the VIM-2 gene was the epidemic MBLs isolates in this area, and sequence analysis of the blaVIM-2 products revealed high identity.We considered that the resistance of Pserdomonas aeruginosa are rising,and following the carbapenem antibiotics are used the metallo-β-lactamase-producing isolates will be increasing.This increases the opportunity of the MBLs gene being transferred to various types of bacteria.Therefore we must be carefully use this kind of antibiotic to prevent the metallo-β-lactamase- Producing Pseudomonas aeruginosas spread.Infections by MBL-carrying Pseudomonas aeruginosa (MBL-PA) is the most in the neurosurgery.These resulted in higher in-hospital mortality than those by non-MBL-PA. It can be seen that as soon as possible to find out an effective screening method of MBLs, to cut off the dissemination, to invent the effective inhibitor of MBLs,it will be the focus of future research.