Distribution of Virulence Factors in Vancomycin-Resistant Enterococci Isolated from Clinical and Intestinal Samples

Virulence factors in enterococci play an important role in the pathogenesis of enterococcal infection and colonization. The aim was to determine the prevalence of genes encoding virulence factors in VRE from clinical and intestinal samples. A total of 163 VRE (94 clinical and 69 intestinal) isolated from patients treated in the University Hospital were studied. Species identification was performed by Vitek 2. The genes for vancomycin resistance (<i>vanABCDMN</i>) and virulence factors (<i>ace</i>/<i>acm</i>, <i>asa1</i>, <i>esp</i>, <i>efaA</i>, <i>cylA</i>, <i>gelE</i> and <i>hyl</i>) were detected by multiplex PCR. The prevalence of virulence genes with respect to clinical and intestinal <i>E. faecium</i> was compared using Fisher's exact test and <i>p</i> > 0.05 was considered statistically significant. Carriers of virulence factors were 107 VRE: 85 clinical and 14 intestinal <i>E. faecium</i>, 6 intestinal <i>E. gallinarum</i> and single <i>E. durans</i> and <i>E. faecalis</i>. The dominant virulence genes were <i>acm</i> and <i>esp</i>. Genes for virulence factors were not detected in the tested <i>E. casseliflavus</i> isolates. There was no statistically significant difference in the prevalence of the genes encoding virulence determinants between the clinical and intestinal <i>E. faecium</i>. High diversity of virulence determinants was found in 107 VRE and a combination of two genes, mainly <i>acm</i> and <i>esp</i>, was detected in 94 of them.