Witte W, Klare I, Werner G (2001): Transfer of antibiotic resistance genes in Enterococcus faecium of animal and human origin and the significance of meat products
Mitt. Lebensm.unters. Hyg. 92: 28-41.

The use of avoparcin and virginiamycin as antibiotic growth promoters in animal husbandry has created a considerable reservoir of transferable, plasmid determined resistance against glycopeptides and streptogramins, respectively, in Enterococcus faecium from meat animals. The following review elaborates on glycopeptide resistance in enterococci mediated by the vanA gene cluster and streptogramin resistance in E. faecium mediated by vatD, vatE and ermB. The structure formulas of quinnupristin/dalfopristin and virginiamycin, as well as the transposon structure carrying the vanA gene cluster, are presented. Molecular typing of resistant E. faecium isolates and characterization of the resistance genes reveal that spread of resistance is mainly brought about by the dissemination of resistance genes among a variety of different plasmids and strains. Because humans acquire resistant enterococci from meat animals by contaminated meat products, the need to prevent further spread of antibiotic resistance from the bacterial flora of food animals via meat products through the implementation of global regulations is stressed.