Role of motility in experimental cholera in adult rabbits

The role of motility in the pathogenesis of cholera was evaluated in ligated ileal loops of adult rabbits. Four strains of Vibrio cholerae (including both Inaba and Ogawa serotypes of both classical and El Tor biotypes) were compared with their aflagellated, but fully toxigenic and prototrophic, isogenic derivatives as to their ability to produce fluid accumulation in the rabbit gut. The nonmotile mutants required an at least 100-fold-higher dose than their respective wild-type strains to produce comparable fluid accumulation responses. The decreased ability of nonmotile strains to produce a fluid response was not due to their failure to multiply in vivo, since they increased in numbers in the rabbit ileum at the same rate as the wild-type strains, but probably was related to their inability to associate with the intestinal mucosa. After 3 h of incubation, 45 to 53% of motile, [35S]-labeled cells adsorbed to the intestinal wall, whereas only 3 to 15% (depending upon the strain) of the nonmotile bacteria were associated.