Serotypes of verocytotoxigenic Escherichia coli isolated from cattle and buffalo calf diarrhoea

A total of 45 verocytotoxin (VT)-producing Escherichia coli (VTEC) strains obtained from diarrhoeic cattle and buffalo calves were serotyped. These strains were classified into 27 ‘O’-groups, many of them being associated with VT for the first time. The frequently isolated VTEC serotypes were O86:H26, O128:H31, and OX6:H2. However, the great diversity of VTEC O-groups is to be noted, those associated with VT production being O3, O5, O6, OX6, O7, O20, O21, O49, O75, O76, O80, O84, O86, O88, O103, O116, O117, O118, O137, O153 and O159. It is interesting that 11 of the 41 O-groupable strains belong to well recognized human enteropathogenic E. coli (EPEC) O-groups.