3-hydroxy fatty acids in a lipopolysaccharide-like material from Treponema denticola strain FM.

Treponemes are associated with major oral diseases such as apical and marginal periodontitis. Lipopolysaccharide (LPS) is regarded as an important virulence factor in these diseases. It is unclear whether LPS is present in oral treponemes. Therefore, the present study was undertaken to examine if a common oral treponeme-Treponema denticola-possesses LPS. A modified Westphal method (phenol water-ethanol-hexane extraction) was used to extract LPS-like material from T. denticola, reference strain FM. It was cultivated in prereduced anaerobically sterilized pectin medium. Gas chromatography and gas chromatography-mass spectrometry of the extract detected three hydroxy fatty acids: C3-OH-i-13:0, C3-OH-i-15:0, and C3-OH-16:0 which constituted 12% of its fatty acid content. These acids, commonly regarded as markers of LPS, suggested the presence of LPS in T. denticola.