Occurrence of K88-negative escherichia coli serotypes in pigs with post weaning diarrhoea.

Faecal swabs from pigs with post weaning E. coli diarrhoea in 43 different herds were bacteriologically examined. A survey of the isolated haemolytic E. coli strains showed that only 1 of the examined strains possessed the K88 antigens and that E. coli strains belonging to serogroup O149:K91 were most frequently isolated. The results suggest that the K88 antigen is of minor significance in the development of post weaning diarrhoea associated with E. coli serotype O149:K91.