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.
