Abstract
Enterococci are fecal indicator bacteria that are widely distributed in water environments such as sewage, urban rivers, and coastal areas. In addition, nosocomial infectious diseases caused by vancomycin-resistant enterococci (VRE) have arisen in medical institutions. VRE have the potential to exist not only in hospital facilities but also in environmental water sources. In this study, VRE and other antibiotic-resistant enterococci isolated from sewage and rivers in the provincial city of Miyazaki, Japan, were investigated. There were no VRE in sewage and river water samples. However, vancomycin-intermediate-resistant enterococci were observed in both samples. The percentages of vancomycin-intermediate-resistant isolates from sewage and river water were 8.4% (20/239 isolates) and 1.9% (5/261 isolates), respectively. More than 60% of isolates from sewage and river water were resistant to erythromycin and tetracycline, which are universally applicable antibiotics. The monitoring performed monthly between June 2011 and July 2012 indicated that the percentages of antibiotic-resistant enterococci fluctuated every month. Enterococci resistant to various antibiotics exist ubiquitously in the water environment.
