Events in the pathogenesis of experimental cholera: role of bacterial adherence and multiplication

Pathogenic, and laboratory-derived non-adherent, non-motile, streptomycin-dependent and attenuated strains of Vibrio cholerae, were injected into the ileal loops of adult rabbits. The pattern of bacterial adherence and multiplication was studied. It was shown that all the strains multiplied to the same extent in the intestine; multiplication per se had no role in pathogenesis except when the infecting dose was low. Vibrio strains differed in their capacity to adhere to the intestine. A good correlation was found between adherence and pathogenesis. While adhesive strains were pathogenic, the poorly adhesive strains proved to be poor pathogens. There was no trace of toxin the ileal loops inoculated with poorly adhesive strains and very little in the diarrhoeal fluid produced by pathogenic strains. Adhesive strains adhered poorly to the intestine of immunised animals. It is suggested that adherence is concerned in the release of toxin and thus plays an important role in the pathogenesis of cholera.