Bacteroides Oralis, Proposed New Species Isolated from the Oral Cavity of Man.

Loesche, W. J. (Forsyth Dental Center and Harvard School of Dental Medicine, Boston, Mass.), S. S. Socransky, and R. J. Gibbons. Bacteroides oralis, proposed new species isolated from the oral cavity of man. J. Bacteriol. 88:1329-1337. 1964.-Twenty-seven strains of oral bacteroides were characterized and compared with a National Collection of Type Cultures strain of Bacteroides fragilis as well as strains of intestinal bacteroides. A combination of acid end products, gas production, pentose fermentation, and 10% bile tolerance afforded a basis for separation of oral strains from intestinal strains. The oral strains produced succinic, lactic, acetic, and formic acids but no gas. They were inhibited by 10% bile, and did not ferment xylose and arabinose. Intestinal strains consistent with the description for B. fragilis produced succinic, formic, acetic, and propionic acids and gas, with a few strains forming lactic acid. They were stimulated by 10% beef bile, and fermented xylose and arabinose. The oral strains are sufficiently different from intestinal strains of the B. fragilis type, so that they appear to constitute a separate species. It is proposed that they be recognized as B. oralis, sp. n.