In a previous publication authors divided Shigella flexneri Type 4 into two groups M and N according to biochemical behaviours, especially by those three biochemical reactions, i.e. Wood's trimethylamine-oxide reduction test, the nicotinic acid-requirement test and the mannitol-fer-mentation; the members of the M group ferment mannitol, and require nicotinic acid or its amide as growth factor but do not reduce trimethylamine oxide while the members of the N group react just reversely.
The Shigella bacilli of the N group are a so-called Shigella saigonensis named by Pacheco and Rodriques in 1930, who characterized it as mannitol-non-fermenting but related to other Shigella flexneri organisms antigenically. Until the year 1950, when Sasagawa isolated some of the Shigella flexneri Type 4 which belong to the M group, there had been no such a form of Type 4 bacilli isolated in Japan, authors believed therefore that only Shigella Type 4 bacilli of the N group, namely Shigella saigonensis had prevailed in Japan. However, recently authors themselves also did isolate some of those bacilli belonging to the M group of Shigella flexneri Type 4 to confirm Sasagawa's finding.
On the other hand, Shigella flexneri Type 4 is divided into three subtypes, 4a, 4b and 4c according to the new classification of Shigella recommended by the Enterobacteriaceae Subcommittee of the International Microbiologists' Society, and it was announced that the subtypes 4a and 4b were classified because of the differences in their minor group antigens but 4c was divided just according to its biochemical characteristics. It seemed to us unfair that Shigella flexneri Type 4' was divided antigenically on the one hand and biochemically on the other hand, because such a way might confuse the principle on the classification itself. In this respect, authors attempted to analyze the antigenic structure of this type of Shigella flexneri bacilli to make the subtying of them clearer, and to contribute to the knowledge of type distribution of Type 4 flexneri bacilli.
抄録全体を表示