THE SO-CALLED PATHOGENIC HALOPHILIC BACTERIA AND THE OTHER GROUP OF ALLIED ORGANISMS

Using a liquid medium, 5% NaC1 containing mannitol ethyl violet broth1) for the selective cultivation of the so-called Takikawa's pathogenic halophilic bacteria, the authors isolated 42 strains having a halophilic property from coastal sea-water, sewage, and the other contaminated waters. Regarding general biological characters, 33 strains among isolated organisms were found to be identical with those of the Takikawa's group. Comparative investgation between Takikawa's strains and the isolated ones revealed that all of the organisms may be devided into two groups, I and II. The group II organisms have the following characteristics; fermentative of sucrose, ability to grow in a 10% NaC1 containing broth, production of acetylmethylcarbinol, and swarming on an agar plate, while the organisms belong to group I are lack in the aforementioned characters. The majority of the Takikawa's strains were found to belong to the group I, on the other hand almost all of the strains isolated from natural environments in the present study, belonged to the group II. These facts may strongly suggest that the true pathogenic organisms belong to group I, and the group II organisms which are much more abundant in natural environment than the group I are non-pathogenic.