Parasutterella secunda sp. nov., isolated from human faeces and proposal of Sutterellaceae fam. nov. in the order Burkholderiales.

A novel, strictly anaerobic, non-spore-forming, Gram-reaction-negative coccobacillus bacterium, designated strain YIT 12071(T), was isolated from human faeces. Biochemically, this strain was largely unreactive and asaccharolytic. Growth of this strain in peptone-yeast-extract broth was weak, producing no visible turbidity, and no short-chain fatty acids were detected as an end product of metabolism. Following 16S rRNA gene sequence analysis, strain YIT 12071(T) was found to be most closely related to Parasutterella excrementihominis (90  % sequence similarity) and phylogenetically distinct from other known genera belonging to the order Burkholderiales. Biochemical data supported the affiliation of this strain with the genus Parasutterella. Strain YIT 12071(T), therefore, represents a novel species of the genus Parasutterella, for which the name Parasutterella secunda sp. nov. is proposed. The type strain is YIT 12071(T) (=DSM 22575(T) =JCM 16078(T)). On the basis of 16S rRNA gene sequence analysis, species of the genera Sutterella and Parasutterella form a distinct and deep evolutionary lineage of descent in the order Burkholderiales. This lineage could not be associated with any of the four known families of the order Burkholderiales. The distinct phylogenetic position and the unusual combination of chemotaxonomic characteristics shared by these genera, such as the predominant quinones and cellular fatty acid compositions, suggest that they constitute a novel family in the order Burkholderiales, for which the name Sutterellaceae fam. nov. is proposed to accommodate the genera Sutterella and Parasutterella.