Colicinogenicity of Escherichia coli isolates from healthy and diarrhoeic goats

A total of 550 E. coli isolates--250 from apparently healthy, and 300 from diarrhoeic West African pigmy goats were tested for colicinogenicity. 33.2% of strains from apparently healthy animals were colicinogenic as against 56% recorded for strains from animals with diarrhoea. Of the 251 colicinogenic E. coli strains from both groups of animals, 76.5% were Type I while 23.5% belonged to Type II. Identified colicins from the healthy animals consisted of types G, K, E2, A and V in decreasing frequency of occurrence, whereas those from goats with diarrhoea were made up of types V, B, E1, G, E2, E3, and Ia also in decreasing frequency of occurrence. In contrast to isolates from healthy animals, there was a marked variation in the colicin spectra of Types I and II E. coli from the diarrhoeic animals--that of Type I being much broader. The Public Health significance of possible transfer of multiple drug resistance from colicinogenic E. coli strains to other enterobacteria is also discussed.