Vancomycin-resistant enterococci(VRE)

The incidence of Enterococcal nosocomial infection has increased since 1980s. Most Enterococci are intrinsically resistant to many kinds of antibiotics, therefore, therapeutic drugs for enterococal infectious disease are limited to a few antibiotics such as ampicillin, gentamicin and vancomycin. However, since the first report of penicillinase producing E. faecalis in 1983, ampicillin-resistant strains have been increasing, furthermore, these strains often associated with high-level resistance to aminoglycosides. The yearly usage of vancomycin increased because vancomycin was only effective drug against such resistant strains and worldwide spread of multidrug-resistant MRSA which vancomycin is only effective. However, High-level vancomycin-resistance strains of E. faecium were first isolated in England in 1986. In 1990s, VRE have been spreading all over the world, especially, the emergency of multidrug-resistant strains, which are resistant to high concentrations of ampicillin or gentamicin or to vancomycin in USA, brought serious therapeutic dilemmas. This review focuses on the background in emergence of VRE, the relation with use of avoparcin, is used for growth promotion in farm animals, the mechanism of resistance, and the prevention of the spread of vancomycin resistance.