Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         [crown] Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Domain Bacteria Woese et al. 1990 [paraphyletic?]
             Superphylum "Proteobacteria" Craig et al. 2010
               Phylum "Gammaproteobacteria" Garrity et al., 2005 [monotypic]
                 Class Gammaproteobacteriaᵀ Garrity et al. 2005
                   Order "Enterobacteriales" Garrity and Holt 2001 nom. nud. [monotypic]
                     Family Enterobacteriaceaeᵀ Rahn 1937 (Approved Lists 1980)
                       Genus Serratia Bizio 1823 (Approved Lists 1980)
                         Serratia marcescensᵀ Bizio 1823 (Approved Lists 1980)
                           Serratia marcescens subsp. marcescensᵀ (Bizio 1823) Ajithkumar et al. 2003