Phylogenetic evidence for the transfer of Eubacterium lentum to the genus Eggerthella as Eggerthella lenta gen. nov., comb. nov.

Eubacterium lentum has unique phenotypic characters within the genus Eubacterium. The 16S rRNA sequence of Eubacterium lentum was determined and its phylogenetic position was defined. This micro-organism is a member of the genus Eubacterium but it is not closely related to Eubacterium limosum, the type species of the genus Eubacterium, and is nearer to Collinsella aerofaciens and Coriobacterium glomerans. A PCR-based identification system using species-specific primers designed on the basis of DNA sequences encoding the 16S rRNA of strains of Eubacterium lentum, Collinsella aerofaciens and Coriobacterium glomerans is described. A species-specific primer set can distinguish Eubacterium lentum from Eubacterium limosum or closely related species including Collinsella aerofaciens, Coriobacterium glomerans and Atopobium species. This species-specific PCR method can be used to identify Eubacterium lentum-like species isolated from human faeces. On the basis of the 16S rRNA sequence divergence from Collinsella aerofaciens and Coriobacterium glomerans and the presence of unique phenotypic characters, a new genus, Eggerthella gen. nov., is proposed for Eubacterium lentum, with one species, Eggerthella lenta comb. nov. The type strain of Eggerthella lenta is JCM 9979T.