Fermentation product analysis in the identification of black-pigmented bacteria from periodontitis.

A quantitative procedure is described for the analysis of fermentation products of eight representative black-pigmented Gram-negative anaerobic bacterial strains (Porphyromonas gingivalis 381, Porphyromonas gingivalis ATCC 33277, Prevotella intermedia ATCC 25611, Prevotella nigrescens ATCC 33563, Prevotella melaninogenica ATCC 25845, Prevotella denticola ATCC 33185, and Prevotella loescheii ATCC 15930) from oral sites in humans, using gas-liquid chromatography. This procedure for the identification of clinical isolates was carried out and the results were in agreement with those obtained by other chemical, biochemical and serological assays. The isolates were classified as Prevotella intermedia, Prevotella nigrescens and two serotype groups of Porphyromonas gingivalis, based on the quantity of fatty acids.