Listeria
Listeria is a genus of bacteria that contains ten species. Named after the English pioneer of sterile surgery Joseph Lister, the genus received its current name in 1940.
Listeria species are facultatively anaerobic, Gram-positive bacilli. The major human pathogen in the
Listeria genus is
L. monocytogenes. It is usually the causative agent of the relatively rare bacterial disease, listeriosis, a serious infection caused by eating food contaminated with the bacteria. The disease affects primarily pregnant women, newborns, adults with weakened immune systems, and the elderly. Listeriosis is a serious disease for humans; the overt form of the disease has a mortality rate of about 20 percent. The two main clinical manifestations are sepsis and meningitis. Meningitis is often complicated by encephalitis, a pathology that is unusual for bacterial infections.
Listeria ivanovii is a pathogen of mammals, specifically ruminants, and has rarely caused listeriosis in humans.