[Various aspects of competitive relationship between Shigella and Escherichia coli]

One of the aspects of antagonistic relations could be the competence of microorganisms for specific sites of attachement to the epithelium common for shigellae and some E. coli serological types; this was demonstrated on a model of shigella-induced keratoconjunctivitis and in experiments with the HEp-2 cells infected with H3-glucose-labeled Sh. flexneri 5a, with combined administration of the latter with E. coli 08 and 028. The data obtained emphasized the importance for the development of the infectious process of the primary stage of shigella attachment to the epithelium. It was also revealed that the presence of common pili in the strains or production of colicine by bacteria intensified the antagonistic activity of E. coli, irrespective of their serological type.