The Incidence and Distribution of Colicinogenic and Colicin-sensitive Escherichia coli in the Gastro-intestinal Tract of the Pig

SUMMARY: Eleven Escherichia coli serotypes recognized as being pathogenic for the pig and 231 commensal strains of E. coli from pigs were examined for colicinogeny and colicin sensitivity. Of the commensal strains, 437% were colicinogenic, and produced 11 known colicins and others that could not be identified. The only pathogenic strains shown to be colicinogenic were those of the 0141 serogroup which produced colicin B.

All the pathogenic strains were sensitive to colicins produced by the commensal strains. The implications of these findings are discussed in relation to the dominance of pathogenic serotypes in colibacillosis.