spirochaete

spirochaete |ˈspʌɪrə (ʊ )kiːt |(US spirochete ) ▶noun a flexible spirally twisted bacterium, especially one that causes syphilis. ●Treponema and other genera, order Spirochaetales; Gram-negative. ORIGIN late 19th cent.: from spiro- 1 ‘in a spiral ’ + Greek khaitē ‘long hair ’.