Pectobacterium carotovorum (Pcc) and Pectobacterium atrosepticum (Pca) were originally classified as Erwinia carotovora subspecies carotovora and subspecies atroseptica, respectively. These species (or subspecies) were
members of the soft rot group of erwinias and are taxonomically closely related to Erwinia chrysanthemi (recently reclassified as multiple Dickeya species; see previous section).