Glycopeptides susceptibility among enterococci isolated from a poultry farm in Sao Paulo, Brazil (1996/1997)

Enterococci resistance to glycopeptides was evaluated em Brazilian poultry fed with feed supplemented with avoparcin as growth promoter. The susceptib ility to the glycopeptides avoparcin, teicoplanin and vancomycin was determ ined for 217 enterococci isolated from cloacal swabs (one swab per bird) in tests and controls groups. Tests group comprised three groups (A, B and C) of Hubbard broiler-chickens 14, 21 and 35 days old, respectively. These bi rds were from one single farm, with a common feed source supplemented with avoparcin (10 mg/kg of feed). Controls groups (1 and 2) comprised 25 and 42 days old broilers, respectively, obtained from the Faculty of Veterinary M edicine's aviary (University of Sao Paulo) where avoparcin was never used. No glycopeptide resistant enterococci strain was found, but an increase of Enterococcus faecium in faeces of chickens fed with avoparcin, independent of the age of the bird, was detected.