any of a group of very small rod-shaped bacteria that live in biting arthropods (as ticks and mites) and cause disease in vertebrate hosts; they cause typhus and other febrile diseases in human beings
例句
用作名词(n.)
It is caused by Rickettsia rickettsii and spread by ticks of the genus Dermacentor.该病由立克次氏体引起，由革蜱属的蜱类传播。
