The family Coriobacteriaceae

Abstract

Coriobacteriaceae is a family within the order Coriobacteriales (phylum Actinobacteria), which includes 30 species belonging to 14 genera: Adlercreutzia, Asaccharobacter, Atopobium, Collinsella, Coriobacterium (type genus), Cryptobacterium, Denitrobacterium, Eggerthella, Enterorhabdus, Gordonibacter, Olsenella, Paraeggerthella, Parvibacter, and Slackia. These bacteria are normal dwellers of mammalian body habitats such as the oral cavity, the gastrointestinal tract, and the genital tract. In the gut, Coriobacteriaceae carry out functions of importance such as the conversion of bile salts and steroids as well as the activation of dietary polyphenols. However, they can also be considered as pathobionts, because their occurrence has been associated with a range of pathologies such as bacteremia, periodontitis, and vaginosis. Coriobacteriaceae are usually nonmotile, nonspore-forming, nonhemolytic, and strictly anaerobic bacteria that grow as small rods; stain Gram-positive; are negative for oxidase, urease, and indole production; and are characterized by a high G+C content of DNA (around 60 mol%). Many species are asaccharolytic and possess a variety of aminopeptidases. Typical cellular fatty acids are C 18:1 w9c as well as saturated fatty acids (C 14:0, C 16:0, C 18:0) and derivatives thereof. The production of menaquinone-6 homologues of vitamin K 2 seems also to be an attribute of the family. Taking into account the aforementioned metabolic functions of Coriobacteriaceae, their clinical relevance and the fact that an increasing number of novel species have been described very recently, this bacterial family will surely gain an increasing attention in the field of host/bacteria interactions in the near future.