[Epidemiological search for vancomycin-resistant enterococci in mainland of the Ryukyus]

During the period from January through December 2007, a total of 1,814 stool specimens from the inpatients of nine regional hospitals in mainland of the Ryukyus, were tested to identify vancomycin-resistant enterococci (VRE). All the stool specimens were primarily cultured onto the VRE selective agar plates, and a total of 195 specimens yielded positive enterococcal growth. Of 195 isolates, VRE screening agar tests identified 106 phenotypic VRE isolates, consisting 24 isolates of Enterococcus casseliflavus, 12 of E. faecalis, 4 of E. faecium, and 66 of E. gallinarum. Then, the 106 VRE isolates were tested for vanA and vanB genes by polymerase chain reaction, the results indicating none of the isolates were positive for vanA or vanB genes. With these results, it can be concluded that, at present, mainland of the Ryukyus is VRE-free area, and it is necessary to continue careful search for incoming and spreading of VRE positive for vanA and vanB genes in Okinawa.