Molecular analysis of vancomycin-resistant enterococci isolated in Debrecen, Hungary
Abstract number: P2122
Domradi S., Konya J., Dombradi V., Szabo J.
Objectives: Although vancomycin resistant enterococci (VRE) are common nosocomial pathogens, they have been rarely isolated in Hungary. The aim of the present study was to explore the prevalence of VRE colonising hospitalised patients in the hospitals of the Medical School at the University of Debrecen, and to identify the van resistance genes.
Methods: 3946 clinical samples collected between January 2004 and November 2006 were found to contain various enterococcus strains by the Bacteriological Diagnostic Laboratory. These isolates were screened on 6 mg/l vancomycin containing BHI agar plate according to CLSI (NCCLS). 44 screen-positive isolates were tested by E-test for vancomycin and teicoplanin resistance. Suspicious colonies were also investigated by the VITEK 2® system. PCR amplification of the Enterococcus faecalis and Enterococcus faecium ddl genes as well as Enterococcus casseliflavus and E. faecalis sodA genes were used for species identification. Multiplex PCR was preformed for the detection of the vanA, vanB, vanC1/C2, vanD, vanE and vanG genes. VanC1 and vanC2 were differentiated by a method based on the restriction digestion of the PCR products by HindIII and SalI enzymes. The van gene carrying PCR products were confirmed by DNA sequencing.
Results: We identified the vanC1 resistance gene in 4 clinical samples: 1 E. faecalis and 1 E. casseliflavus from urine, and 1 E. faecalis from wound secretion. In one urine sample both E. faecalis vanC1 and E. casseliflavus vanC2 resistance gene carrying bacteria were found. A highly resistant sample (vancomycin MIC > 256) from femoral wound was found to contain vanA carrying E. faecalis.
Conclusion: This is the first report on the occurrence of the vanC1 resistance gene in Hungary. Furthermore, we found a new vanC2 variant, having a sequence that is slightly different from the one reported in the database. We conclude, that molecular screening of the resistance genes is important in the diagnostics of VRE, and the identification of the carrier by PCR is more reliable than standard biochemical methods
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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