[Frequence of K99 antigen and antibioresistance in Escherichia coli from calves in France (author's transl)].

During the winter of 1979-1980, an epizootiological study of diarrhoeic calves revealed the presence of K99+ E. coli among 8.2 p. cent of clinically healthy calves and in 18.9 p. cent of diseases calves. Some calves which seemed healthy on the day of sampling possibly became diarrhoeic on the following days. In diarrhoeic calves, K99+ E. coli were mainly found during the early life, i.e. in 33.7 p. cent of calves less than 4 days old. These results were obtained with 147 healthy calves and 1053 diarrhoeic calves. They confirmed previous results obtained with more limited numbers of animals. Moreover, K99+ E. coli were found in all breeding systems. Antibiotics resistance among the isolated E. coli were very high, especially in K99+ strains. The results proved the interest of E. coli K99 diagnosis in liquid diarrhoea of very young calves.