gram-positive, rod-shaped, non-capsulated, non-sportulating bacterium.

L. monocytogenes infects both human and aminals causing meningitis, sepsis, and abortion, L.ivanovii is restricted to sheep and cattle, in which it causes septicemic disease, neonatal sepsis and abortion, but no brain infection. The infectious disease caused by these bacteria is known as listeriosis. The other species are generally considered nonpathogenic.

Bacteria; Firmicutes; Bacilli; Bacillales; Listeriaceae; Listeria