By John N. Sofos, Ph.D.,
University Distinguished Professor
Colorado State University,
Center for Meat Safety & Quality
If for the fresh meat industry the No. 1 enemy is Escherichia coli O157:H7 (E. coli O157 or O157), the corresponding concern for the ready-to-eat (RTE) meat and poultry sector is Listeria monocytogenes (Listeria or Lmono), the pathogen that causes listeriosis. While O157 is responsible for most bacterial contamination recalls of fresh beef, Lmono holds first place in the RTE meat and poultry industry. Although Lmono has been known as an animal pathogen since the early 1990s, it was not until the early 1980s that it was documented as a foodborne cause of severe and fatal human illness. Foods implicated in the transmission of Lmono to humans include luncheon and deli meats, hot dogs, raw vegetables, unpasteurized milk and products made with unpasteurized or raw milk.