"Coli septicaemia" causes large losses in the breeding of chicks, broilers, and turkeys. It has been shown that the most frequent causes of this disease are the serotypes O2:K1, O78:K80, O1:K1. O8:K? (1, 2, 4, 5, 20). The purpose of this work was a closer definition of the antigen structure of smooth and rough forms frmn serotypes O2:K1 and O78:K80, coliform bacilli, with the help of immunoelectrophoresis and passive hemagglutination, as well as examination of the comrposition of simple sugars (monosaccharides) in extracts obtained from the above mentioned serotypes.
Two hundred and twenty E. coli strains isolated from cases of poultry colibacillosis in Poland were studied serologically. One hundred and ninety-six (89 per cent) were identified as belonging to 37 different O groups. Ninety-three strains (42 per cent) belonged to 6 serotypes considered to be pathogenic for poultry. The seriotypes were: O1:K1, O2:K1, O3:K?, O8:K?, O22:K?, O78:K80. The greatest number of strains were represented by serotypes O2:K1 and O8:K. In the studied strains serogroups considered to be pathogenic for cattle and humans were found. Out of the remaining strains, O90:K? Was encountered most frequently, followed by O93:K? and O84:K?. These serotypes had so far not been considered to be pathogenic for poultry.