Determination of virulence and multidrug resistance genes with polymerase chain reaction method in vancomycin-sensitive and -resistant enterococci isolated from clinical samples

Abstract

Background/aim: Enterococci play an important role in nosocomial infections. Therefore, this study investigates multidrug resistance (MDR) 1 gene areas in the pathogenicity of enterococci and virulence genes in both vancomycin-sensitive enterococci (VSE) and vancomycin-resistant enterococci (VRE) strains.

Materials and methods: Virulence genes and MDR genes of enterococci were investigated by polymerase chain reaction (PCR).

Results: We evaluated a total of 116 isolates, 93 being VRE and 23 being VSE. In this study, 95.6% of VRE (n = 93) were Enterococcus faecium (n = 89) and 4.3% were E. faecalis (n = 4), while 17.4% of VSE (n = 23) were E. faecium (n = 4) and 82.6% were E. faecalis (n = 19). The vanA MDR1 gene was detected in all VRE isolates. Among virulence genes, esp and hyl were detected in E. faecium, an enterococcus with the highest resistance to vancomycin, and gelE was detected in E. faecalis, an enterococcus with the highest sensitivity to vancomycin. Three or more virulence genes were identified only in VSE strains. We consider that it is a significant result that VSE had more virulence genes than VRE. Only esp was seen in VRE E. faecium strains.

Conclusion: This study includes experimental results on the association of virulence characteristics in VRE and VSE strains.