RESULTS:

Obligately anaerobic Gram-stain-positive small-chain coccobacilli strains 12EGH17T and 18CBH55 were isolated from faecal samples of healthy Japanese humans. Strain 12EGH17T showed the highest 16S rRNA gene sequence similarity to Sellimonas intestinalis BR72T (95.5 %) Coprococcus comes ATCC 27758T (94.4 %) and Clostridium nexile DSM 1787T (93.7 %). The percentage of conserved proteins values between the genome of strain 12EGH17T and that of the members of the genus Sellimonas were >54 % suggesting that strain 12EGH17T belongs to the genus Sellimonas . The digital DNA–DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strains 12EGH17T and 18CBH55 were higher than the cut-off values of species demarcation (90 % dDDH and 99 % ANI) indicating these two strains are the same species. However the dDDH and ANI values of these strains were lower than the cut-off values of species demarcation against other strains (<30 % dDDH and <79 % ANI). These results indicate that the isolates should be considered to represent a new species of the genus Sellimonas . The isolates were differentiated from the type species S. intestinalis by the ability of aesculin hydrolysis. Based on the collected data strains 12EGH17T and 18CBH55 represent a novel species in the genus Sellimonas for which the name Sellimonas catena sp. nov. is proposed. The type strain of S. catena is 12EGH17T (=JCM 35622T=DSM 114916T).