The existing taxonomy of oral treponemes is not satisfactory. This is due to the fact that these strict anaerobic bacteria are not easily cultivated or differentiated. Therefore, new techniques that can contribute to improved cultivation, classification, and identification of these fastidious organisms should be welcomed, In the present study capillary zone electrophoresis (CZE) was used to distinguish oral treponemes by their metabolic product patterns generated in a liquid medium. To our knowledge this technique has not previously been used in bacterial chemotaxonomy. Reference strains of Treponema denticola, Treponema pectinovorum, Treponema vincentii, Treponema socranskii subspecies buccale and Treponema socranskii subspecies socranskii were cultured anaerobically in duplicate on different days in Pectin medium for 4 days at 37 degrees C under nitrogen atmosphere, Treponemal cells were harvested by centrifugation. Thereafter, their supernatants were filtered through 0.22-mu m Millipore filters and subjected to CZE. The resulting electropherograms clearly distinguished T. denticola, T. pectinovorum and T. vincentii. Minor differences were detected between T. socranskii subspecies buccale and T. socranskii subspecies socranskii. Subspecies were clearly different from species. It seems that CZE of culture metabolites, which showed high resolution and good reproducibility, may be a valuable tool in the chemotaxonomy of oral treponemes, even at the subspecies level.
