Proposal of two novel species, Allocoprococcus similis gen. nov., sp. nov. and Faecalimonas hominis sp. nov., isolated from human faeces and genome-based reorganization of the genus Coprococcus

The obligately anaerobic, Gram-stain-positive coccobacilli strains OB7620 T and OB7656 T were isolated from faecal samples of healthy Japanese volunteers. Strain OB7620 T showed the highest 16S rRNA gene sequence similarity to Coprococcus comes ATCC 27758 T (98.4%) and Clostridium nexile DSM 1787 T (96.3%). Strain OB7656 T showed the highest 16S rRNA gene sequence similarity to ‘ Gluceribacter canis ’ NATH-2371 T (97.7%), C. nexile DSM 1787 T (94.8%) and Faecalimonas umbilicata EGH7 T (94.8%). These findings indicate that the two strains represent novel species. Genomic analysis clarified the phylogenetic relationship of C. comes with the species cluster designated as Coprococcus sensu stricto , which includes the type species, C. eutactus . As C. comes is distinct from the species of Coprococcus sensu stricto , C. comes is reclassified into a novel genus, Allocoprococcus , as Allocoprococcus comes gen. nov., comb. nov. Although strain OB7620 T is closely related to C. comes , it is a distinct species. Therefore, we propose the name Allocoprococcus similis gen. nov., sp. nov. The type strain is OB7620 T (=DSM 118890 T =JCM 37173 T ). Because Coprococcus catus differs from Coprococcus sensu stricto , it has been placed in a novel genus, Pseudocoprococcus , as Pseudocoprococcus catus gen. nov., comb. nov. We also concluded that Coprococcus immobilis and Coprococcus intestinihominis are the same species and belong to the new genus Pseudocoprococcus . As C. immobilis has priority, we propose the name Pseudocoprococcus immobilis gen. nov., comb. nov. We also concluded that C. nexile and Clostridium phoceensis are the same species in the genus Faecalimonas . As C. nexile has priority, we propose the name Faecalimonas nexilis comb. nov. Coprococcus mobilis and ‘ G. canis ’ should also be reclassified within the genus Faecalimonas . Therefore, we propose the name Faecalimonas mobilis comb. nov. and Faecalimonas canis sp. nov. As strain OB7656 T is related to ‘ G. canis ’ but is a different species, we propose the name Faecalimonas hominis sp. nov. The type strain is OB7656 T (=DSM 118889 T =JCM 37172 T ).