STUDIES ON THE ENTEROPATHOGENIC, FACULTATIVELY HALOPHILIC BACTERIA, VIBRIO PARAHAEMOLYTICUS

In recent years, it was demonstrated that cultures of Vibrio parahaemolyticus isolated from human diarrheal stools were different from those from sea fish and sea water in a hemolytic activity on a special blood agar, which was named the Kanagawa phenomenon. In the present studies, the finding has been confirmed by using 3370 cultures of the vibrios. Ninety-six % of the vibrios isolated from human patients gave positive (hemolytic) reaction in the test of the phenomenon, while only one % of the vibrios from sea fish and sea water gave positive results in the test. No relationship was observed between the phenomenon and serological and biochemical characteristics.Enteropathogenicity of the cultures of the vibrios positive in the Kanagawa phenomenon was evident by the results of feeding tests according to Takikawa and Aiiso and Fujiwara and by a case of laboratory infection of the culture to a male who took gastroenteritis by administration of approximately 106 viable cells of the hemolytic vibrios in the test of the phenomenon. On the other hand, feeding tests were carried out with 15 human volunteers to clarify enteropathogenicity of the negative (non-hemolytic) vibrios. None of them took illness, although over 109 cells of the vibrios were administered. Thus, the authors considered, as a rule, that the vibrios giving negative Kanagawa phenomenon may be nonpathogenic to human beings.