A strictly anaerobic, Gram-positive, short-rod/coccobacillus-shaped bacterial strain, designated 7-10-1-b(T), was isolated from the colon of a patient suffering from acute Crohn's disease. The isolate formed small, pale-white, semi-translucent colonies on solid cultivation media. The strain was catalase-positive and metabolized only a small number of carbon sources. Whole-cell fatty acids consisted predominantly of saturated fatty acids (89 %), of which 15 : 0 anteiso was the major component. The polar lipids phosphatidylglycerol and diphosphatidylglycerol as well as four glycolipids were identified. 16S rRNA gene sequence analysis revealed that the isolate represents a distinct lineage within the family Coriobacteriaceae and has 94.6 % identity to the type strain of [Eggerthella] hongkongensis, the phylogenetically closest bacterial species. On the basis of the analyses performed, the new genus and species Gordonibacter pamelaeae gen. nov., sp. nov. is described, with strain 7-10-1-b(T) (=DSM 19378(T) =CCUG 55131(T)) as the type and only strain of Gordonibacter pamelaeae. Also, based on the chemotaxonomic data obtained for all type strains of the neighbouring genus Eggerthella, we propose that Eggerthella hongkongensis Lau et al. 2006 be transferred to a new genus as Paraeggerthella hongkongensis gen. nov., comb. nov.; the type strain of Paraeggerthella hongkongensis is HKU10(T) (=DSM 16106(T) =CCUG 49250(T)).