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Enterococci were isolated from faecal droppings of chickens in broiler and layer farms and the susceptibilities to nine therapeutic antimicrobial agents and six growth‐promoting antibiotics were determined by the agar dilution method. Resistance to therapeutic antimicrobial agents such as ampicillin, clindamycin, erythromycin, streptomycin, tetracycline or tylosin was more frequent in enterococcal isolates from broiler farms than in those from layer farms. Resistance to ofloxacin was rare, occurring in only one (0·7%) of the Enterococcus faecium isolates from broiler farms. Resistance to growth‐promoting antibiotics such as avilamycin, salinomycin and virginiamycin was common among isolates from broiler farms. Of the E. faecium isolates from broiler farms, 12·4% were resistant to avilamycin and 27·4% were resistant to virginiamycin. Resistance to salinomycin was detected in all enterococcal species, ranging from 12·4% of E. faecium isolates to 50% of E. hirae isolates.

Isolation of Glycopeptide-Resistant Enterococci from Chickens in Japan Avoparcin is a glycopeptide antibiotic that has been used as a growth-promoting agent for food animals in many countries, except the United States and Canada. In human medicine, glycopeptide-resistant enterococci (GRE) have become an increasingly serious problem in the treatment of nosocomial infections (6, 8, 10). In Europe, GRE have been isolated from animals, meat, the environment, and healthy humans outside hospitals (1, 2, 4, 7, 9), suggesting the possibility of transmission of GRE from food animals to humans via the food chain (2-4). In Japan, two glycopeptides have been approved as feed additives for chickens-avoparcin in 1985 and orienticin in 1994-but no papers have been published on the isolation of GRE from chickens in Japan. Then, a nationwide survey was conducted to isolate GRE from the fecal droppings of chickens on farms in Japan. Prior to isolation of enterococci from fecal droppings, the distribution of avoparcin from the manufacturers to chicken farms was traced for 1 year across the country. Avoparcin was confirmed to have been brought into 24 prefectures in the period from December 1995 to November 1996. Fecal droppings were sampled from 39 broiler farms in these 24 prefectures. Fecal droppings of chickens not exposed to avoparcin were sampled from 11 broiler farms and 35 layer farms in 23 prefectures where no avoparcin had been distributed in the same period. Fecal samples were taken during a 1-week period from 11 December to 18 December 1996. Enterococci were isolated on bile esculin azide agar plates. MICs were determined for avoparcin, orienticin, and vancomycin by the agar dilution method with Mueller-Hinton agar. Two hundred and sixty-three enterococci were isolated from the 35 broiler farms confirmed to have used avoparcin. Eight (3.0%) of them were GRE, originating from three (8.6%) farms. Of these eight strains, seven were identified as Enterococcus faecalis and the remaining one was identified as E. faecium. Five of the seven E. faecalis strains originated from the same farm, and the remaining two strains originated from an

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