Listeria Monocytogenes Products

The genus Listeria comprises six species: L. monocytogenes, L. innocua, L. welshimeri, L. seeligeri, L. ivanovii and L. grayi. Listeria monocytogenes, the most commonly isolated pathogenic member, is associated with a wide spectrum of human and animal diseases. In the smear from the original tissue, L. monocytogenes may appear as gram-positive coccobacilli that may be confused with Streptococcus agalactiae (group B), enterococci, or Corynebacterium spp. Listeria is differentiated from streptococci by a positive catalase test. L. monocytogenes is the only species of the genus Listeria that has been clearly documented as a pathogen for humans. The forms of disease caused by this organism are myriad and age-related. The most common clinical manifestations are meningitis and septicemia. Listeria monocytogenes, a food-borne intracellular animal and human pathogen, interacts with infected host cells both prior to entry and during the intracellular phase of infection.