Sellimonas catena sp. nov., isolated from human faeces

Obligately anaerobic, Gram- stain-positive, small -chain coccobacilli, strains 12EGH17(T) and 18CBH55, were isolated from faecal samples of healthy Japanese humans. Strain 12EGH17(T) showed the highest 16S rRNA gene sequence similarity to Sellimonas intestinalis BR72(T) (95.5 %), Coprococcus comes ATCC 27758(T) (94.4 %) and Clostridium nexile DSM 1787(T) (93.7 %). The percent-age of conserved proteins values between the genome of strain 12EGH17(T) and that of the members of the genus Sellimonas were 54 %, suggesting that strain 12EGH17(T) belongs to the genus Sellimonas. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strains 12EGH17(T) 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 12EGH17(T) 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 12EGH17(T) (=JCM 35622(T)=DSM 114916(T)).