Studies on the Asakusa Group of Enterobacteriaceae (Edwardsiella Tarda)

A group of the Enterobacteriaceae has been studied using 256 cultures which were isolated mainly from snakes. Although the term“Asakusa”group was first used as the designation for the organisms by Sakazaki and Murata (1962), a scientific name Edwardsiella tarda was recently proposed by Ewing and his co-workers.The members of the group are closely related to the Salmonella group in hydrogen sulfide production and lysine decarboxylation, but differ in their indol production, and mannitol-, arabinose-, xylose-, and trehalose-non-fermentable characteristics.Within the 256 cultures of the group, seventeen O groups and eleven H antigens were established, and an antigenic schema was set up for 18 serotypes of the group.It was considered that the organisms are normal intestinal inhabitants of reptiles. Several cultures were isolated from human pathological materials, but no conclusive results on pathogenicity have been obtained in this study.