[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain Bacteria Woese et al. 1990
     Phylum "Spirochaetes" Garrity and Holt 2001
       Class "Spirochaetes" Cavalier-Smith, 2002 see Class Spirochaetes Cavalier-Smith 2002
         Order Spirochaetales Buchanan 1917 (Approved Lists 1980)
           Family "Brachyspiraceae" nom. ined. see Family Brachyspiraceae Paster 2012
             Genus Brachyspira Hovind-Hougen et al. 1983
               Brachyspira hyodysenteriae (Harris et al. 1972) Ochiai et al. 1998