Treponema denticola (ex Brumpt 1925) sp. nov., nom. rev., and identification of new spirochete isolates from periodontal pockets.

Standard growth and isolation methods were used to obtain five new treponema strains in pure culture from deep periodontal pockets. The strains were identified to the species level by various methods, including agglutination, immunofluorescence, a dot blot immunoassay, electron microscopy, gas-liquid chromatography of metabolic volatile fatty acids, and DNA hybridization. Two isolates were strains of Treponema socranskii; the other three were strains of "Treponema denticola," a species described in 1925 by Brumpt. Because no type strain was designated for this species previously, the name was not included on the Approved Lists of Bacterial Names and has no current nomenclatural standing. We propose that Treponema denticola (ex Brumpt) sp. nov., nom. rev. is a valid and distinct species of the genus Treponema and designate strain ATCC 35405 as the type strain and strains ATCC 33520 and ATCC 35404 as reference strains. T. denticola appears to be the species that is most frequently isolated from periodontal pockets. Unless new isolation and cultivation techniques are introduced, it appears that present technology can yield only isolates belonging to the currently described oral anaerobic spirochete species and that there is little chance of isolating the larger treponemes.