YawsYaws is a tropical infection of the skin, bones, and joints caused by the spirochete bacterium Treponema pallidum pertenue. The disease begins with a round, hard swelling of the skin, in diameter. The center may break open and form an ulcer. This initial skin lesion typically heals after 3–6 months. After weeks to years, joints and bones may become painful, fatigue may develop, and new skin lesions may appear. The skin of the palms of the hands and the soles of the feet may become thick and break open.
SpirochaeteA spirochaete (ˈspaɪroʊ-ˌkiːt) or spirochete is a member of the phylum Spirochaetota (-ˈkiːtiːz), (synonym Spirochaetes) which contains distinctive diderm (double-membrane) gram-negative bacteria, most of which have long, helically coiled (corkscrew-shaped or spiraled, hence the name) cells. Spirochaetes are chemoheterotrophic in nature, with lengths between 3 and 500 μm and diameters around 0.09 to at least 3 μm. Spirochaetes are distinguished from other bacterial phyla by the location of their flagella, called endoflagella which are sometimes called axial filaments.
Treponema pallidumTreponema pallidum, formerly known as Spirochaeta pallida, is a spirochaete bacterium with various subspecies that cause the diseases syphilis, bejel (also known as endemic syphilis), and yaws. It is transmitted only among humans. It is a helically coiled microorganism usually 6–15 μm long and 0.1–0.2 μm wide. T. pallidum's lack of either a tricarboxylic acid cycle or oxidative phosphorylation results in minimal metabolic activity. The treponemes have a cytoplasmic and an outer membrane.
SyphilisSyphilis (ˈsɪfəlɪs) is a sexually transmitted infection caused by the bacterium Treponema pallidum subspecies pallidum. The signs and symptoms of syphilis vary depending in which of the four stages it presents (primary, secondary, latent, and tertiary). The primary stage classically presents with a single chancre (a firm, painless, non-itchy skin ulceration usually between 1 cm and 2 cm in diameter) though there may be multiple sores. In secondary syphilis, a diffuse rash occurs, which frequently involves the palms of the hands and soles of the feet.