Evaluation of vancomycin-resistant Enterococci in ICU hospitalized patients

Background: Enterococci which are frequently found in hospital-acquired infections (HAIs), are becoming more important as a result of the emergence of multidrug-resistant strains, this study was done to evaluate the prevalence of vancomycin resistance in clinical isolates of Enterococci in ICU hospitalized patients and the detection of its virulence factors. Methods: Samples were cultured and identified by conventional bacteriological methods, confirmation of identification and antibiotic susceptibility were done by VITEK 2 compact system. Conventional PCR was used for detection of identification genes (ddlE. faecalis, ddlE. faecium), vancomycin resistance genes (vanA, vanB) and virulence genes (asa1, esp, gelE, hyl, cylA). Results: Bacterial growth was detected in 2470 samples, Enterococci were isolated from 74 of these samples. Enterococcus spp., that were isolated from blood cultures represented 50%, urine cultures 47.3% and sputum cultures 2.7%. Approximately 82.4% of isolates were identified by VITEK 2 compact system as E. faecalis and 17.6% were E. faecium. Vancomycin resistance rate in enterococcal isolates was 20.3%. Resistance gene (vanA) was detected in 8.2% of E. faecalis and 15.4% of E. faecium, vanB gene wasn't detected. Regarding E. faecalis virulence genes; gelE gene was the most prevalent 57.4%, asa1 gene was detected in 45.9% and esp gene was detected in 44.3%. E. faecium virulence genes; gelE gene was detected in 61.5%, esp gene 53.8% and asa1 gene 30.8%. Conclusion: Vancomycin resistant Enterococci represent 20.3% of enterococcal isolates, vanA was the only resistance gene detected. Virulence gelE gene was significantly expressed in vancomycin sensitive enterococcal isolates.