Genome-based analyses indicate that subsp. and subsp. do not merit separation to subspecies status.

The species currently comprises two subspecies, viz. subsp. and subsp. . The latter species was created by considering the differentiating endospore-formation capability of isolate KRED. A member of the Subcommittee on the Taxonomy of Enterobacteriaceae for the International Committee on Systematics of Prokaryotes conducted a re-examination of KRED and failed to detect its endospore-forming capability, thereby questioning the validity of subsp. as a separate subspecies. Nevertheless, the taxonomic allocation of subsp. has been followed till date. To obtain clarity for taxonomic allocation based on genome-based analysis, we sequenced the genome of type strain subsp. KRED=DSM 17174 and carried out the analyses recommended to define the subspecies. As a result, DSM 17174 does not satisfy the genomic criteria for defining a subspecies: i.e. does not form a distinguishable clade by overall genomic related indexing and phylogenomic treeing. Also, there is currently no other rationale for separate recognition of this species. We propose the removal of the subsp. designation to avoid further confusion in the literature.