Treponema denticola is a Gram-negative, obligate anaerobic, motile and highly proteolytic spirochete bacterium. It dwells in a complex and diverse microbial community within the oral cavity and is highly specialized to survive in this environment. T. denticola is associated with the incidence and severity of human periodontal disease. Elevated T. denticola levels in the mouth is considered one of the main etiological agents of periodontitis. T. denticola is related to the syphilis-causing obligate human pathogen, Treponema pallidum subsp. pallidum.