sp. nov., a novel member of the Cholerae clade.

A number of bacteria with close resemblance to have been isolated over the years by the Centres for Disease Control and Prevention (CDC), which could not be assigned a proper taxonomic designation on the basis of the results from preliminary identification methods. Nine such isolates have been found to share 16S rRNA gene identity exceeding 99 % with yet DNA-DNA hybridization (60.4-62.1 %) and average nucleotide identity values (94.4-95.1 %) were below the species cut-off, indicating a potentially novel species. Phylogenetic analysis of core genomes places this group of isolates in a monophyletic clade, within the 'Cholerae clade', but distinct from any other species. Extensive phenotypic characterization reveals unique biochemical properties that distinguish this novel species from . Comparative genomic analysis reveals a unique set of siderophore genes, indicating that iron acquisition strategies could be vital for the divergence of the novel species from a common ancestor with . On the basis of the genetic, phylogenetic and phenotypic differences observed, we propose that these isolates represent a novel species of the genus , for which the name sp. nov. is proposed. Strain 2521-89 (= DSM 112461=CCUG 75318), isolated from lake water, is the type strain.