Procaryotic Genera Domain "Bacteria" Woese et al. 1990 Phylum Spirochaetes Garrity and Holt 2001 [monotypic] Class "Spirochaetes" Cavalier-Smith, 2002 [monotypic] see Class Spirochaetes Cavalier-Smith 2002 Order Spirochaetales Buchanan 1917 (Approved Lists 1980) Family Leptospiraceae Hovind-Hougen 1979 (Approved Lists 1980) Genus Leptospira Noguchi 1917 (Approved Lists 1980)