Abstract
Problems have been left unsettled on the mechanism of food poisoning of bacterial origin. It has been assumed, however, that an important role may be played in an outbreak of such food poisoning by histamine which is produced in a food during the process of its decomposition.
In the present investigation, an effort was made to detect, by some technique of serological reaction, histamine-producing organisms from among bacteria attached to raw fish. The materials used were gills collected from 16 fish. Precipitation tests were carried out between heat-extracts of organisms attached to the gills and anti-rabbit serum prepared with a histamine-producing organism (a strain of Morganella). Then bacterial strains of positive reaction were examined for ability of producing histamine, and isolated bacterial strains subjected to bacteriological examination. The results obtained are summarized as follows.
1. A distinctly positive test was shown between the antigen prepared from the gill of a horse-mackerel and anti-serum.
2. Two of the strains isolated from the same fish as mentioned above exhibited positive precipitation tests when the protein fractions of their bodies were used with the anti-serum, and positive agglutination tests when their live organisms and the same anti-serum were subjected to the tests.
Bacteriological examination proved that the two strains were those of Achromobacter. It was confirmed, therefore, that there were a common antigen between these strains and the strain of Morganella employed.
3. It was confirmed by paper chromatography that the two strains mentioned above were capable of producing histamine.
4. A total of 57 strains were isolated from all the materials used. They consisted of 35 strains of Achromobacter, 10 strains of Bacterium anitratum, 7 strains of Flavobacterium, and 5 strains of Rettgerella.
