Spirochaeta

A genus of motile bacteria (order Spirochaetales) containing presumably Gram-negative, flexible, undulating, spiral-shaped rods that may or may not possess flagelliform, tapering ends. The protoplast is spirally wound around an axial filament. No obvious periplast membrane or cross-striations occur. These organisms are motile by means of a creeping motion over the surfaces of supporting objects. They are not parasitic but are found free-living in fresh or sea water slime; they are commonly found in sewage and foul waters. At present the genus contains five species. The type species is S. plicatilis. [Mod. L. fr. G. speira, a coil, + chaite, hair]

- S. obermeieri SYN: Borrelia recurrentis.

- S. plicatilis a very large species (sometimes as long as 200 μm) of bacteria; it is nonparasitic, so far as known; it is the type species of the genus S..

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Spi·ro·chae·ta .spī-rə-'kēt-ə n a genus (the type of the family Spirochaetaceae) of spirochetes distinguished by a flexible undulating body with the protoplasm wound spirally around an elastic axis filament and comprising as now restricted various chiefly aquatic forms or formerly these together with important pathogens now placed in the genera Treponema, Borrelia, and Leptospira