[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain Bacteria Woese et al. 1990
     Phylum "Proteobacteria" Garrity et al. 2005 see Superphylum Proteobacteria Craig et al. 2010
       Class Epsilonproteobacteria Garrity et al. 2006
         Order Campylobacterales Garrity et al. 2006
           Family Helicobacteraceae Garrity et al. 2006
             Genus Helicobacter Goodwin et al. 1989
               Helicobacter pullorum Stanley et al. 1995