Any of various irregularly coiled helical spirochetes of the genus Borrelia, some species of which cause relapsing fever in humans, other mammals, and birds.

• 包柔氏螺旋体属一种包柔氏螺旋体属螺旋不规则的螺旋体，其中一些会引起人类、其他哺乳动物和鸟类的回归热病