ABSTRACT
Members of the genus Treponema are spiral-shaped bacteria that are classiŠed in the family Spirochaetaceae, order Spirochaetales. Along with those from the genus Borrelia, Treponema bacteria represent the most important human pathogens within the family. The genus Treponema has a great variety of natural hosts, including humans, other primates, rabbits, cattle, dogs, and termites. The best-known pathogen of this genus is Treponema pallidum subspecies pallidum, the etiological agent of syphilis. Other pathogenic treponema that cause disease in humans include Treponema carateum-the causative agent of pinta, and two subspecies of Treponema pallidum, T. pallidum subspecies pertenuethe causative agent of yaws, and T. pallidum subspecies endemicum-the etiological agent of endemic syphilis. These treponemes may be propagated in laboratory animals, with the exception of Treponema carateum, which can only be propagated in primates. General characteristics of pathogenic treponemes are summarized in Table 98.1.
