Abstract
Strains of Escherichia coli isolated from documented cases of disease in pigs and belonging to a wide range of pathogenic serotypes were tested for their ability to produce a heat labile verotoxin (VT). The strains isolated from oedema disease all produced VT, indicating that the cytotoxin detected by the vero-cell assay was identical to "oedema disease principle". Strains belonging to the serotypes associated with enterotoxic diarrhoea were VT-. Not all the strains belonging to the recognised oedema disease serotypes (O141:K85, O139:K82 and O138:K81) produced VT, but the VT- strains were not associated with outbreaks of clinical disease.