Sero-logical typing of strains of E. coli isolated from cases of chronic respiratory disease of poultry

422 E. coli isolates from 171 poultry carcasses affected with C.RJD. and 30 from 11 healthy birds were typed serologically. 183 isolates from affected birds belonged to the ten most prevalent O groups (O: 78, O: 87, O: 3, O: 35. O: 15, O: 95, O: 74, 0: 109, 0: 20 and 0: 141). Of these only two (0: 35 & 0: 141) were included in the 6 most prevalent groups found in healthy animals.