what disease is caused by bacterium treponema pallidum
Treponema pallidum Treponema pallidum is a spirochaete bacterium with subspecies that cause treponemal diseases such as syphilis, bejel, pinta, and yaws. It is a helically coiled microorganism usually 6–15 µm long and 0.1–0.2 µm wide.[1] The treponemes have a cytoplasmic and an outer membrane. Using light microscopy, treponemes are visible only by using dark field illumination. They are Gram negative, but some regard them as too thin to be Gram stained.