Halophilic Bacteria

Epidemics in 1961 and a few comments on the pathogenesis

Abstract

Special section for pathogenic halopilic bacteria (chairman-Dr. H. Fukumi) was admitted in the Food Hygine Committee of the Welfare Ministry in 1961. And the Center of the Research on Halophilic Bacteria was established in the National Institute of Health. In 1961 670 outbreaks (30, 800 persons) of food poisoning were reported in Japan. Only 30 percent of them were decided on their causative agents. And the greater part of the decided agents was halophilic bacteria. (Fig. 2, 3, 4)
Epidemics of the halophilic bacteria food piosoning were concentrated in the hot season. (Fig. 2, 3)
The distribution of the epidemics is shown in Fig. 1.
The antigen types were determined as in Table 1.
Most of the strains from patient's material do not produce acid from sucrose, where as most of the strains from marine water, marine fishes or other food stuffs produce acid from sucrose. (Table 2)
This information suggests importance of the sucrose (?) strains in contrast to the nearly negligible sucrose (+) strains.
In 1957 a group of three boys and a girl fell ill with symptoms of acute gastroenteritis, offering commonly sucrose (+) strains of halophili bacteria. The strain was reported as antigen type 7 (in new classification type 10). And the causative food of this outbreak was presumed to be tsukudani of shelllfish. (Table 4 and Fig. 5)
Note: “tsukudani”-preserved food boiled down in soy.
Salt requirement of the strains collected from human patients was reconsidered, re: ulting in the following new interesting view.
Sucrose (+) strains prefere a higher concentration of salt, being unable to grow in the media with a minimum concentration, (Fig. 7), while most of the sucrose (-) strains prefere a somewhat lower concentration of salt, being able to barely grow in the media with a minimum concentration of salt. (Fig. 6)
In 1961 two dolphins in Enoshima Marine Land died of acute entritis, and one of them offered two types of sucrose (+) strains of halophilic bacteria, and the other sucrose (-) strain. (Table 3)
Salt requirement of these strains are similar to that of the strains from human materials, in response to the activity of acid production from sucrose. (Fig. 8)
Vibrio comma has similar properties to pathogenic halophilic bacteria, growing better in media with salt, the optimum concentration however, being lower than that of halophilic bacteria, thus well growing in the medium without salt. (Fig. 9)
Consequently the following conclusion was made. Pathogenicity of these bacteriae with similar properties including Vibrio comma is influenced by their own salt requirement. Sucrose (+) strains of halophilic bacteria have little chance to arive at the entrance to human body, while Sucrose (-) strains have advantages in it. Vibrio comma can tolerate environments without salt on land. The difference of salt requirement between these bacterIae must have an effect upon the pathogenic activity and the ability tto stay in human intestine.