Prevalence of VanA and B Genotype Among Vancomycin Low Resistant Enterococcus in Fecal Normal Flora and Clinical Samples Isolated From Tehran’s Hospitals

Background: Vancomycin-Resistant Enterococci (VRE) pose an emerging problem in Iran hospitals. Objectives: The present study was undertaken to determine the prevalence of van genes among vancomycin low resistant Enterococccus (VLRE) isolate in Tehran hospitals. Materials and Methods: Totally 162 and 152 isolates of enterococcal species were obtained from fecal and clinical samples of hospitalized patients between March and November of 2012. The antibiotic susceptibility of the isolates and minimum inhibitory concentration (MIC) were determined according to CLSI. The presence of the van A and B resistant genes in VLREs isolates were evaluated by PCR method. Results: VLRE accounted for 162 (38.4%) and 159 (38.7%) of Enterococal isolates from clinical and fecal flora samples respectively (MIC’s in the range of 16 to 64 μg/mL). VanA and vanB genotypes were detected with polymerase chain reaction (PCR) in 85 (27%) and 35 (11%) of VLRE isolates, respectively. Conclusions: VLRE cause serious problems in healthcare settings because their detection is difficult and treatment of these infections may not be successful. These species are miss-identified as vancomycin susceptible isolates. By detection of VLRE, we can evaluate perspective of vancomycin high level resistant Enterococcus rate in future.