Clonal relationships among bovine pathogenic Escherichia coli producing surface antigen CS31A.

Forty-two Escherichia coli strains producing surface antigen CS31A isolated from bovine infections were characterized with respect to OKH serotypes, outer membrane protein (OMP) electrophoretic patterns, allozymes for esterases A, B, C, I and biotypes. A large majority of the strains could be clustered in a limited number of groups of clonally related strains with diverse O serogroups. CS31A producing Escherichia coli strains thus appear to have a common genetic background and are representative of an important part of bovine pathogenic Escherichia coli.