Persistence of vancomycin-resistant enterococci (VRE) on Norwegian broiler farms.

Five Norwegian broiler farms previously identified as housing broilers carrying vancomycin-resistant enterococci (VRE) were examined for the presence of VRE 4 years after avoparcin was banned. Environmental samples were obtained from empty, cleaned broiler houses. Faecal samples were collected weekly from the flock housed after the environmental sampling. The hatchery from where the chicks originated was also sampled. VRE were found to be present in the farm environment after depopulation and cleanup of the broiler houses. Within 3 weeks after introduction to the farm, all broiler flocks tested positive for VRE. VRE were not isolated from the hatchery.