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 (vanABCDMN) and virulence factors (ace/acm, asa1, esp, efaA, cylA, gelE and hyl) were detected by multiplex PCR. The prevalence of virulence genes with respect to clinical and intestinal E. faecium was compared using Fisher's exact test and p > 0.05 was considered statistically significant. Carriers of virulence factors were 107 VRE: 85 clinical and 14 intestinal E. faecium, 6 intestinal E. gallinarum and single E. durans and E. faecalis. The dominant virulence genes were acm and esp. Genes for virulence factors were not detected in the tested E. casseliflavus isolates. There was no statistically significant difference in the prevalence of the genes encoding virulence determinants between the clinical and intestinal E. faecium. High diversity of virulence determinants was found in 107 VRE and a combination of two genes, mainly acm and esp, was detected in 94 of them.