Molecular characterization of vancomycin-resistant Enterococci / 中国医学科学院学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the homology and resistant mechanism of vancomycin-resistant Enterococci (VRE) isolates.</p><p><b>METHODS</b>A total of 9 VRE isolates were collected from 2006 to 2007 at PUMC hospital. The susceptibility of these isolates to 10 different antibiotics including vancomycin was tested by E-test. These strains were processed by brain heart infusion agar screening in the presence of vancomycin (6 microg/ml), and were analyzed for genotypic characteristics using the multiplex PCR. The homology of the isolates was determined by pulsed-field gel electrophoresis (PFGE).</p><p><b>RESULTS</b>All the 9 VRE isolates were identified as Enterococci faecium. The visual analysis of PFGE patterns revealed 6 different PFGE types. The vanA gene was confirmed by PCR and sequencing in 9 VRE isolates, which were consistent between phenotype and genotype for glycopeptides resistance.</p><p><b>CONCLUSIONS</b>Only vanA genotype was detected in PUMC hospital. Clonal dissemination, horizontal gene transfer, and the selective pressure of antimicrobial agents may contribute to the increase of VRE.</p>