Molecular Characterization of Vancomycin-Resistant Enterococcus faecium Isolates from Patients Admitted to the Intensive Care Unit of Hatay State Hospital.

Objective: In this study, it was aimed to determine vancomycin resistance mechanisms, virulence genes and clonal relationships of 23 vancomycin-resistant Enterococcus faecium (VREfae) strains isolated from patients admitted to intensive care unit of Hatay State Hospital. Materials and Methods: Minimal inhibitor concentration (MIC) values of vancomycin were determined by E-test and antimicrobial susceptibility of the strains was determined by disc diffusion method. The clonal relationship among VREfae isolates was determined by pulsed-field gel electrophoresis (PFGE). Additionally, vancomycin resistance (vanA, vanB, vanC, vanD, vanE and vanG) and virulence genes (asa1, esp, gelE, hyl and cylA) were investigated by polymerase chain reaction (PCR) method. Results: All isolates harbored vanA gene and 17 isolates (73.9%) were positive for at least one virulence gene. The most common virulence gene was esp, which was detected in nine isolates alone and in two isolates together with hly gene. The hly gene was detected in five isolates alone and the other virulence genes (asa1, gelE and cylA) were not observed in any isolates tested. All isolates showed multidrug resistance phenotype. Vancomycin MIC values of the isolates were found to be ≥256 μg/mL by E-test. PFGE analysis revealed 14 different pulsotypes in five clusters (A, B, C, D and E). The presence of identical PFGE patterns indicated that there was a crosstransmission at hospital settings. Conclusion: Continuous surveillance of resistance patterns and molecular characteristics of VRE are needed to reduce the prevalence of infections caused by VRE and to take effective control measures in hospitals. [ABSTRACT FROM AUTHOR]