Listeria monocytogenes Listeria monocytogenes is a short gram-positive rod. Although most gram-positive rods of medi- cal importance are anaerobes, Listeria is an aerobic (rather than anaerobic) organism. It is found widely in soil, sewage, and various animals, as well as in the feces of about 15% (range, 2%-60%) of asymptomatic adults. Infection in children and […]