Analyses of publicly available genomes revealed genetic distances indicating they belong to more than one species.

has been observed to be a member of the gut microbiome. Unfortunately, little is known about this organism in spite of being associated with human fatalities; it is important to understand virulence mechanisms and epidemiological prospective to cause disease. In this study, a patient with chronic neurologic symptoms presented to the clinic with subsequent isolation of a strain with phenotypic characteristics suggestive of . However, whole-genome sequence found the organism to be . Analysis including publicly available genomes found substantial genomic differences as compared to the type strain, indicating this isolate was not . We examined the whole-genome of species and related genera, using comparative genomics to fully examine species identification and toxin production. Orthogonal phylogenetic using the 16S rRNA gene and entire genome analyses that included genome distance analyses using Genome-to-Genome Distance (GGDC), Average Nucleotide Identity (ANI), and a pan-genome analysis with inclusion of available public genomes determined the speciation to be . Two clearly differentiated groups were identified, one including a reference genome (strain DSM-13,479) and a second group that was determined to be , which included our clinical isolate. Also, some genomes reported as were found to belong to other genera, including and . We show that the species have an open pan-genome reflecting high genomic diversity. This study highlights the importance of correctly assigning taxonomic identification, particularly in disease-associated strains, to better understand virulence and therapeutic options.