The Epidemiological and Molecular Characterization of Vancomycin-Resistant Enterococci Isolated from Rectal Swab Samples of Hospitalized Patients in Turkey

Abstract

Background: Vancomycin-resistant enterococci (VRE) are a serious problem all over the world. The present study was conducted to investigate antimicrobial resistance patterns, genotypes, clonal relationship, and virulence factors of VRE species isolated from rectal swab samples of hospitalized patients, patient's relatives, and medical staff at Istanbul University Cerrahpasa Medical School hospital. Methods: The VRE isolates were typed with an automated VITEK system and their antibiotic sensibilities were analysed by disc diffusion and Etest (R) method. The molecular characterization and clonal relationships were performed using a PCR method and virulence genes by sequence typing. Results: A total of 100 (10.3%) of the 971 patients were colonized with VRE. None of the investigated 25 patient's relatives and 45 medical staff carried VRE. All VRE strains were identified as E. faecium. They were vanA geno-type and originated from a single clone. VRE strains exhibited multi-drug resistance. High-level gentamicin-resistance was 93%. However, lower resistance rates were found for linezolid (40%) and quinopristin-dalfopristin (11%). The enterococcal surface protein gene esp was found positive in 87 of 100 isolates, and four strains were positive for the cylB (cytolysin) gene. Conclusions: The identification of VRE strains to the species level and detection of virulence genes will assist in infection control practices.