無菌海〓に於ける乳酸菌群の定着現象と大腸菌感染に対する桔抗現象について
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概要
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Numerous bacteria are found, in the intestines of ordinary experimental animals. In the study of the effects on animals of initial monoinfection with a single strain of organisms or cross-infection with different kinds of organisms, it is hardly possible to get absolutely accurate results if these organisms were tried on conventionally reared animals. This problem can only be solved by using animals born and reared in a germless atmosphere, since they are free from the intestinal flora which constitutes an important obstacle. Experiments were carried out in germ-free guinea pigs raised for 20 days in HMC-2 type germless rearing apparatus after having been taken unborn from the mother's womb, in order to study the effects of monoinfection or cross-infection with Lactobacillus acidophilus, Streptococcus faecalis and Escherichia coli M_1 separated from the feces of parent females. Following oral administration of the organisms to baby germ-free guinea pigs, organisms detected in their feces were counted every day. Twenty days after the administration, the animals were killed, and the organisms detected among the intestinal villi were counted. Investigations were performed on the kinds of organisms detected in the intestines, and in vitro experiments were carried out to study how different kinds of organisms reacted when they were thrown into each other's company. The results are summarized as follows : 1. It proved fairly difficult to detect L. acidophilus in the feces and intestines of conventionally reared guinea pigs. 2. Once lodged in the intestines of the germ-free guinea pigs, L. acidophilus continued to multiply, though slowly. 3. Oral administration of L. acidophilus and Str. faecalis to germ-free guinea pigs caused transient intestinal hypersensitisvity. There was a slight diarrhea. 4. When L. acidophilus or Str. faecalis once lodged in the intestines of germ-free guinea pigs, the intestinal mucosa and lymphatic system reacted in self defence against E. coli M_1 in such a manner as to resist its deleterious effect. There was antagonistic symbiosis between L. acidophilus and symbiosis between Str. faecalis and E. coli M_1. 5. In the study of the reaction of Str. faecalis and E. coli M_1 to each other when they were thrown into each other's company, results of in vitro experiments were not in keeping with those of experiments with germ-free guinea pigs. 6. Either L. acidophilus or Str. Faecalis settled in all the parts of the intestines of germ-free guinea pigs.
- 千葉大学の論文
- 1960-09-28