Description of sp. nov. and sp. nov., derived from human clinical materials, emendation of Stormo 2019 and emendation of the genus to include species which are strict anaerobes.

The (HACEK) group genus contained a single species, for many years. In November 2019, was described after recovery from a brain abscess and blood culture in Norway. Coincidentally, characterization of 22 Gram-negative bacteria resembling from 17 Canadian patients had been underway. Seven isolates from five patients were conclusively identifiable as . One (NML 120819) was deemed to represent a species of the genus most closely related to . Fourteen isolates had 97.6 to 98.8% similarities to by 16S rRNA gene sequencing, forming three distinct groups by genome analyses. The largest contained ten anaerobic isolates from eight patients recovered from blood, brain, bone and other abscesses; upon re-evaluation, this group was found to be most consistent with . A second facultatively anaerobic clade consisted of two ocular isolates from one patient and a sinus isolate from a second patient. The third taxon consisted of a single strictly anaerobic blood culture isolate. The novel taxa, like , were poorly reactive biochemically and difficult to discern from each other phenotypically and chemotaxonomically, including by cellular fatty acids. MALDI-TOF (Bruker) and whole-genome sequencing were used to further characterize isolates. Draft genomes for the strains had similar DNA G+C contents (55.38-58.53 mol%) while sizes varied from 1.82 Mb to 2.54 Mb. We propose here emendations of the genus and the species , as well as describing sp. nov. NML 130454 (=LMG 30894=NCTC 14180) and sp. nov. NML 02-A-017 (=LMG 30896=NCTC 14179), on the basis of these findings.