Spirochete (spirochaeta) is a class of elongated, curved spiral, the movement of the living wave of prokaryotic cell-type microorganisms, with the basic structure of bacteria, the cell wall has lipopolysaccharide and wall acid, spirochetes are divided into dense spirochetes (such as the spirochete of syphilis), sparse spirochetes (such as the spirochete of fever), leptospiral, etc.; the spirochete of syphilis has a uniform spiral of 8-12, the ends of the sharp and straight; the spirochetes of leptospiral Leptospira is elongated, more numerous and densely packed, with one or both ends curved in the shape of a hook, and the bacterial body is often flexed in the shape of a C-shaped or S-shaped.