Investigation of virulence resistance genes and biofilm presence in enterococci isolated from blood cultures

Enterococci play an important role in both nosocomial and community-acquired infections. Virulence genes and the presence of biofilm make it difficult to treat diseases by enabling them to gain resistance to antibiotics and adhere to host tissues. In this study, virulence genes and biofilm presence were investigated in Enterococci strains isolated from blood culture samples of patients followed up in Van Yüzüncü Yıl University Dursun Odabaş Medical Center. Accordingly, a total of 45 strains including 15 vancomycin-resistant enterococci, 15 vancomycin-sensitive E. faecium and 15 vancomycin-sensitive E. faecalis were included in the study. Phoenix M50 (Becton Dickinson, USA) automated system was used for the identification and antibiotic resistance determination of the strains. VanA and VanB resistance genes and asa1, gelE, cylA, hyl, esp virulence genes were investigated by polymerase chain reaction. microplate method was used to investigate biofilm production levels. VanA gene was detected in 86.7% of 15 vancomycin-resistant enterococci isolates, while VanB gene was not detected. Hyl, esp, efaA, gelE, asa1 and cyl genes were detected in 34 (76%), 25 (56%), 14 (31%), 10 (22%), 10 (22%) and 3 (7%) isolates, respectively. In 15 VRE strains, esp (11, 73%) and hyl (9, 60%) genes were detected. In vancomycin-susceptible E. faecium strains, esp (11, 73%) and hyl (10, 67%) genes were detected most frequently; in vancomycin-susceptible E. faecalis strains, hyl (15, 100%) was detected most frequently. In conclusion, biofilm production and virulence factors were higher in E. faecalis isolates, but E. faecium species were more resistant to antibiotics. Although E. faecalis is relatively less resistant to antibiotics, it should be considered together with E. faecium in bloodstream infections due to its virulence genes and biofilm forming properties