Non-Sporulating Anaerobic Bacteria of the Intestinal Tract : I. Occurrence and Taxonomic Relationships.

This investigation was undertaken mainly to extend the observations of Eggerth and Gagnon (1933) and Weiss and Rettger (1937) on the occurrence of non-spore-forming, obligately anaerobic rod-shaped bacteria in the human intestine. Paths soon led to a study of relationships of the various organisms to each other, and of the gram-negative types to certain other closely related bacteria. A voluminous but scattered literature has accumulated which deals with the isolation and study of non-sporulating anaerobes, not only from the normal intestinal tract, but also from a variety of lesions in the human and animal body (see Weinberg, Nativelle and Pr6vot, 1937; McCoy and McClung, 1939). Much uncertainty results from a survey of past work, since differences in methods, inconsistent nomenclature, and inherent differences in the organisms themselves have contributed to provide a complex and confusing picture. Do the various pathogens described in the literature represent separate species? Are they distinct from the intestinal forms? And what are the true natural habitats of these organisms? These are questions which arise from examination of previous researches. The occurrence of these anaerobes in nature may be regarded as being immediately referable to the intestinal and respiratory