Procaryotic Genera
   Domain "Bacteria" Woese et al. 1990
     Phylum Nitrospira Garrity & Holt, 2001 [monotypic] see Phylum Nitrospirae Garrity and Holt 2001
       Class "Nitrospira" 2001 [monotypic]
         Order "Nitrospirales" 2001 [monotypic]
           Family "Nitrospiraceae" 2001
             Genus Leptospirillum (ex Markosyan 1972) Hippe 2000