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 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
             8 Genus Pillotina (ex Hollande and Gharagozlou 1967) Bermudes et al. 1988
             9 Genus Treponema Schaudinn 1905 (Approved Lists 1980)