Multilocus Sequence Analysis of Phylogroup 1 and 2 Oral Treponeme Strains.

Periodontal diseases are caused by persistent polymicrobial biofilm infections of the gums and underlying tooth-supporting structures and have a complex and variable etiology. Although Treponema denticola is strongly associated with periodontal diseases, the etiological roles of other treponeme species/phylotypes are less well defined. This is due to a paucity of formal species descriptions and a poor understanding of genetic relationships between oral treponeme taxa. Our study directly addresses these issues. It represents one of the most comprehensive analyses of oral treponeme strains performed to date, including isolates from North America, Europe, and Asia. We envisage that our results will greatly facilitate future metagenomic efforts aimed at characterizing the clinical distributions of oral treponeme species/phylotypes, helping investigators to establish a more detailed understanding of their etiological roles in periodontal diseases and other infectious diseases. Our results are also directly relevant to various polymicrobial tissue infections in animals, which also involve treponeme populations.