Diversity of vancomycin-resistant enterococci in a low endemicity area

Although vancomycin-resistant enterococci (VRE) are frequent nosocomial pathogens worldwide, in Japan their prevalence is low and their molecular epidemiology remains unclear. In The University of Tokyo Hospital (Tokyo, Japan), only five isolates of VRE (vanA-type Enterococcus faecium) were identified in the 20 years before 2010; however, nine isolates of vanB-type E. faecium were identified from 2011 to 2012. Multilocus sequence typing (MLST) revealed that they belonged to five sequence types (ST18, ST78, ST203, ST412 and ST612). Despite the limited isolation, including one from a medical tourist, there was significant diversity in genotypes. Increasing medical travel might enhance the diversity of VRE.