P. Butaye et al., Phenotypic distinction in Enterococcus faecium and Enterococcus faecalis strains between susceptibility and resistance to growth-enhancing antibiotics, ANTIM AG CH, 43(10), 1999, pp. 2569-2570
Susceptibility of Enterococcus faecium and Enterococcus faecalis strains fr
om animals and foods to growth promoting antibiotics used in animal feed wa
s tested by the agar dilution technique. Acquired resistance to bacitracin,
narasin, tylosin, and virginiamycin was seen for both species, and for E.
faecium, resistance to avilamycin and avoparcin was also seen, Drawing the
distinction between susceptibility and resistance based on frequency distri
butions of MICs was easy with avoparcin, avilamycin, and tylosin but diffic
ult with virginiamycin and to some extent also with bacitracin and narasin.