DETECTION OF CLOSTRIDIUM WELCHII (HOBBS TYPE 6) FROM AN OUTBREAK OF COLLECTIVE FOOD POISONING

Abstract

Cl. welchii Hobbs type has been isolated from the dishes served at the wedding party at the time of the outbreak of collective food poisoning. Cl. welchii has hitherto been frequently believed to be the cause of food poisoning in Europe and America. As far as we know, such a case has not yet been reported not only in Japan but also in the Far East. As pointed out repeatedly by Hobbs, Zeissler and other investigators, the most important medium of Cl. welchii food poisoning is believed to be meat, especially animal meat products. However, an outbreak of collective food poisoning due to the oyster contaminated with Cl. welchii was recently reported by Welti et al.⁽⁴⁾ Furthermore, the isolation of Cl. welchii from fish meat has already been recorded in this paper. It is, therefore, considered that not only animal meat products but also marine products can be the important medium of food poisoning, and so a great attention should be paid to the Cl. welchii food poisoning due to fish meat.
The room temperature, at the time of occurrence of the food poisoning, was 30°C and the moisture was 80%. The conditions are considered to be suitable for the germination and growth of the spores surviving the heating when cooked. Since the onset of the poisoning was seen in the persons who took the dishes which had been left under such conditions for more than 10 hours, it is presumed that the spores of Cl. welchii germinated and multiplied in the contaminated fish meat, and thus caused the illness.
Although epidemiological investigation was carried out, the process of contamination in the mackerel, from which the Cl. welchii was isolated, is still unknown.