Molecular characterization of vancomycin-resistant Enterococcus spp. clinical isolates from Hungary and Serbia.

The objectives of this work were to collect and characterize vancomycin-resistant Enterococcus faecium (VREF) clinical isolates from Hungary and Serbia and to analyse their genetic relatedness. VREF isolates were initially typed by PFGE. A selection of VREF isolates representing all participating hospitals was further examined by multiple-locus variable-number tandem repeat analysis (MLVA) and multilocus sequence typing (MLST). VanB VREF isolates (n=18) recovered from blood, urine and faecal cultures at a Budapest hospital between August 2003 and December 2004 were molecularly characterized. Macrorestriction analysis of the isolates revealed their monoclonal relatedness. A cluster of infections caused by 2 distinct VanA VREF clones recovered from 6 departments was identified in a Belgrade hospital in Serbia. The vanA resistance determinant was transferable by in vitro conjugation experiments. We also identified 2 vanA-positive E. gallinarum blood culture isolates in this Belgrade hospital. Molecular typing of representative VREF isolates from Hungary and Serbia by MLVA and MLST revealed that all tested isolates belonged to MLST complex CC17 and the corresponding MLVA cluster 1. Our results extend the documented occurrence of CC17 to a new region in Europe.