Decreased Incidence of VanA-type Vancomycin-Resistant Enterococci Isolated from Poultry Meat and from Fecal Samples of Humans in the Community after Discontinuation of Avoparcin Usage in Animal Husbandry

TLDR

The widespread use of the glycopeptide antibiotic avoparcin in European animal husbandry had led to frequent isolation of VanA‑type vancomycin‑resistant enterococci from animal foodstuffs and nonhospitalized humans, but its discontinuation in several countries began to reduce this prevalence. Following avoparcin withdrawal, VRE prevalence fell sharply in poultry meat and in the gut flora of healthy individuals, demonstrating the impact of glycopeptide selective pressure and the contribution of animal products to community spread of resistant bacteria.

Abstract

The use of the glycopeptide antibiotic avoparcin (AVO) as a feed additive in animal husbandry of many European countries led in 1994-1995 to frequent isolation of VanA-type vancomycin-resistant enterococci (VRE) from commercially produced animal foodstuffs as well as from fecal samples of nonhospitalized persons in Germany (Saxony-Anhalt state). However, at the end of 1997, a decreasing number of such VRE was detected in frozen and fresh poultry meat (chickens and turkeys) from German producers. At this point in time, AVO had been discontinued in animal husbandry for more than 2 and one-half years in Denmark/Norway, nearly 2 years in Germany, and about 8-9 months in all countries of the European Community and Switzerland, respectively. VRE were then only detected in very low concentrations in one-quarter of the poultry meat samples (eight of 31, originating from 18 distinct German producers and bought in 12 different supermarkets). A decline of VRE prevalence was also observed in the gut flora of healthy persons (VRE carriers) in the same region (Saxony-Anhalt state, Germany), having fallen from 12% (12/100) in 1994 when AVO was being used to 6% (6/100) in 1996 and 3% (13/400) in 1997 after it was discontinued. These results likely indicate the importance of antibiotic selective pressure by glycopeptides such as AVO for the presence of VRE in animal meat products from commercial animal husbandry. Additionally, it underlines the role of animal products for the spread of resistant bacteria and transferable resistance genes to humans in the community.