Eubacterium infirmum belongs to a phylogenetic cluster distant from Eubacterium limosum, the type species of the genus and is therefore not a member of Eubacterium sensu stricto. Along with many other members of this poorly-defined genus, E. infirmum will be assigned to a novel genus in due course.

Slow growth on Fastidious Anaerobe Agar + 5% horse blood plates. After 7 days, colonies are approximately 1 mm in diameter, circular, convex and translucent.

Cells are obligately anaerobic, non-spore-forming, nonmotile, Gram-positive, short rods (0.5 µm by 1-2 µm) [1]. Cells occur singly. Asaccharolytic. End-products of metabolism are moderate amounts of acetate and butyrate. The mol% G+C of the DNA is 38.

Found in the human mouth

Isolated from subgingival plaque in periodontitis.