[Frequency of FY and K99 pili in strains of Escherichia coli isolated from diarrheal calves in France].

Epidemiological study of bovine E. coli shows that the FY E. coli pilus which has previously been described and is also known as Att25, can be found in 30 of 415 fecal samples of diarrheic calves, eight of them carrying both FY and K99 pili. The K99 E. coli pilus is present in 86 fecal samples. Strains carrying both FY and K99 pili account for 9% of K99 enterotoxigenic E. coli. K99-, FY+ E. coli do not produce the thermostable enterotoxin (TSa). K99+, FY- or K99+, FY+ E. coli are present mainly in calves under three days old but K99- FY+ E. coli are found whatever the age of the animal.