抄録
Since the serological studies of Escherichia coli were established by Kauffmann and his co-workers, the role of the genus as a causative agent in infection has been generally remarked, and there is no doubt that some types of Escherichia are pathogenic for man and animals. Especially, in the field of infantile diarrhea, numerous pathogenic Escherichia types have been recovered. On the other hand, Kauffmann (1954), Knipschildt (1945), Vahlne (1945), Sjöstedt (1946), Ewertsen (1946), B okhari and Ørskov (1952), Ulblich (1954) and Fey (1954) showed consistently that Escherichia in pathological materials differed from those in normal feces in their serological properties, hemolysis, necrotizing power, and other characteristics. Kauffmann and Knipschildt found that cultures from pathological materials were O-inagglutinable in higher percentages than Escherichia cultures isolated from normal feces. Vahlne reported that in appendicitic materials, almost twice as many strains (78 per cent) belonged to the first twenty-five O groups as in the fecal material (42 per cent) . Ewertsen found that Escherichia cultures isolated from pathological materials belonged to certain O groups, about 80 per cent of which were O-inagglutinable and pathogenic, while cultures detected from normal feces belonged to rare O groups, only 10 per cent of which were O-inagglutinable and 20 per cent pathogenic. Sjöstedt found that Escherichia cultures belonging to certain O groups (2, 4 and 6) were frequently hemolytic, confirming Ewertsen's finding that hemolysis and the capacity to produce necrosis are related. Ulblich described a number of capsulated Escherichia cultures from granulomatosis of fowl, the majority of which belonged to O group 4. Fey reported Escherichia cultures from bovine mastitis; 50 per cent of the groupable cultures were of members of seven frequent O group, 9, 8, 6, 86, 81, 2, and 21. However, such organisms from pathological materials were also found in normal feces.
De and Chatterje (1953) studied the action of Vibrio cholerae on the intestine using rabbit loop experiments. De, Bhattacharya and Sarkar (1956) extended the experiments to determine the pathogenicity of Escherichia cultures isolated from acute and chronic enteritis. In their experiments, however, they found that serological properties of the cultures were not correlated with the pathogenicity for the rabbit intestine.
In December 1956, epizootic of diarrhea in pigs broke out in various districts in Japan. The materials from several cases were submitted to this institute where pathological and verological research by Sasahara and his co-workers and bacteriological examination by the authors were carried out.
Viruses as causative agents of the epizootic, were isolated and studied by Sasahara, and consequently the disease was diagnosed as transmissible gastroenteritis in pigs (Doyle and Hutching, 1946; Bay, Doyle and Hutching, 1951) .
In the bacteriological examination, Escherichia cultures which were possibly related to the disease were found in the intestinal tract of each case.
This paper describes the isolations of Escherichia cultures from the intestinal tracts and organs of 7 cases of the disease and their serological and pathological findings, and reviews the significance of the Escherichia cultures isolated from diseased animals.
