Bacillus circulans is a soil-dwelling human pathogen which has been associated with "septicemia, mixed abscess infections, and wound infections",[1] as well as with meningitis.

[2] This species has been recently transferred into the genus Niallia.

[3] The correct nomenclature is Niallia circulans.

[2] Straight, occasionally curved rods, 2.0-4.2 x 0.5-0.8 μm, motile by peritrichous flagella.

[2] Has ellipsoidal spores which are subterminal or terminal; swelling the sporangia.