Colicinogenicity in Escherichia colI strains isolated from diarrheal and nondiarrheal children in El Shatby Alexandria Pediatric hospital

ABSTRACT

In this study, the colicinogenicity of E. coli strains isolated from 75 diarrheal and 75 non-diarrheal children. The isolation frequency of colicinogenic strains among diarrheal cases was significantly higher [17.07%] than among non-diarrheal cases [5%]. The activity of the diarrheal producer strains was restricted to closely related species. Two out of 7 diarrheal colicinogenic strains [44d and 37d] were found to be of the same type, while none of the diarrheal colicinogenic strains were of E1, V, Ia and Ib colicin types. The production of 5 out of the 7 diarrheal colicinogenic strains was found too be encoded on plasmid. As colicinogenic strains were isolated in only 9.3% and 2.6% in diarrheal and non-diarrheal cases respectively, it is improbable that they could be responsible for any change in the flora of both groups. This does not exclude the fact that colicinogeny could be a factor in the establishment of individual strains in the intestine