Surveillance of vancomycin-resistant Enterococcus in hospitals in Ibaraki prefecture

Abstract

We surveyed the prevalence of vancomycin-resistant Enterococcus (VRE) in six hospitals in Ibaraki prefecture. Three hundred and fifty-five fecal specimens were examined and 18 Enterococcus intermediately resistant to vancomycin were isolated. All of them were vanC genotypes (16 vanC-1 and 2 vanC-2 genotypes) and susceptible or intermediately resistant to ampicillin, teicoplanin, linezolid, and quinupristin-dalfopristin. Neither the vanA nor vanB gene was detected. Two of the vanC genotypes were not motile. We concluded that VRE of either VanA or VanB phenotype or those highly resistant to the antibiotics commonly used against enterococcal infection were not epidemic in this prefecture to date. In addition, we consider that detection of vancomycin-resistant genes should be encouraged for the characterization of VRE, because the vanC genotypes are occasionally motility-negative and can be misinterpreted as other Enterococcus species.