prokaryotes - bacteria see Domain Bacteria Woese et al. 1990
   Domain "Bacteria" Woese et al. 1990
     Phylum "Proteobacteria" Garrity et al. 2005 see Superphylum Proteobacteria Craig et al. 2010
       Class Alphaproteobacteria Garrity et al. 2006
         Order Rickettsiales Gieszczykiewicz 1939 (Approved Lists 1980)
           Family Rickettsiaceae Pinkerton 1936 (Approved Lists 1980)
             1 Genus Orientia Tamura et al. 1995
             2 Genus Rickettsia da Rocha-Lima 1916 (Approved Lists 1980)