Procaryotic Genera Domain "Bacteria" Woese et al. 1990 stat. inval. see Domain Bacteria Woese et al. 2024 Phylum Spirochaetes Garrity and Holt 2001 nom. inval. [monotypic] see Phylum Spirochaetota Garrity and Holt 2021 Class "Spirochaetes" "Garrity and Holt 2001" nom. nud. [monotypic] see Class Spirochaetes Cavalier-Smith 2002 nom. rej. Order Spirochaetales Buchanan 1917 (Approved Lists 1980) Family Spirochaetaceae Swellengrebel 1907 (Approved Lists 1980) 1 Genus Spirochaeta Ehrenberg 1835 (Approved Lists 1980) 2 Genus Borrelia Swellengrebel 1907 (Approved Lists 1980) 3 Genus Brevinema Defosse et al. 1995 4 Genus Clevelandina Bermudes et al. 1988 5 Genus Cristispira Gross 1910 (Approved Lists 1980) 6 Genus Diplocalyx (ex Gharagozlou 1968) Bermudes et al. 1988 7 Genus Hollandina (ex To et al. 1978) Bermudes et al. 1988 nom. illeg. 8 Genus Pillotina (ex Hollande and Gharagozlou 1967) Bermudes et al. 1988 9 Genus Treponema Schaudinn 1905 (Approved Lists 1980)