Vibrio Parahaemolyticus: Infection or Toxicosis?1

Abstract

The facultative halophile Vibrio parahaemolyticus, since its first isolation, has been shown to be toxic for mice and has produced experimental infection when fed to animals and humans. Pathogenicity has been shown to be associated with the presence of a heat-stable hemolysin-the Kanagawa-hemolysin. Previously, investigators reported that most strains of V. parahaemolyticus, regardless of virulence, could produce dilatation in the ligated rabbit gut. We have shown however, that ileal loop reactivity is strongly associated with Kanagawa-hemolysin and, thus, with virulence. Reactivity is obtained with live cell suspensions and the reaction time is dose dependent. Other investigators have reported that preparations of heated cells, cell lysates, culture filtrates, and purified Kanagawa-hemolysin will not produce dilatation in rabbit ileum nor edema in the mouse foot pad. In our studies, cell-free culture filtrates were without effect in the ligated ileal loop, suggesting absence of enterotoxin. Cell wall and heated cell preparations yielded varying ileal reactions. Present data are insufficient to describe the mechanism of virulence of V. parahaemolyticus.

Studies on Enteropathogenic Activity of Vibrio Parahaemolyticus Using Ligated Gut Loop Model in Rabbits

“…This finding is in contrast to that of Twedt (1972) who found that cell-free culture filtrate had no effect on the ileal loop. Culture filtrates employed in the study by Twedt were concentrated by dialysis against Carbowax (Twedt, personal communication).…”

“…The pathogenicity of V. parahaemolyticus in relation to the Kanagawa reaction was first studied with the ligated gut loop tests in rabbits by Twedt (1972). He stated that ileal loop reactivity was strongly associated with their Kanagawa hemolysin production by the vibrios.…”

“…Twedt (1972) reported that cell-wall preparations of V. parahaemolycus induced dilatation of the ligated gut loops inoculated.…”

Serotypes of Vibrio Parahaemolyticus From Clinical and Environmental Sources in Togo (West Africa)

“…Recent studies proved again that the Kanagawa phenomenon is associated with virulence of the strains (Twedt and Brown, 1973;Sakazaki et al, 1974). It remains to be clarified, however, how this property is acquired.…”

Hemagglutination and adhesiveness of epidemiologically distinct strains of Vibrio parahaemolyticus

“…Rabbit ileal loop test. The reactivity of test cultures was determined by a modification of the rabbit ileal loop technique (26,27) in which 1-ml portions of adjusted BHI-salt cultures were injected randomly into individual loops. Sterile broth and known culture controls were used.…”