Listeria monocytogenes (Listeria) is a pathogenic (disease-causing) bacterium that is food borne and causes an illness called listeriosis1. It is frequently overlooked as a possible cause of illness due to its unique growth capabilities. First, it is somewhat difficult for laboratories to grow, and when they do so, Listeria can be confused with common harmless contaminants and disregarded. Second, most bacteria grow poorly when temperatures fall below 40″F, while Listeria survives in temperatures from below freezing (20″F) to body temperature and it grows best at 0″F to 50″F, including the temperature range that we use for refrigeration. As a result, Listeria may be transmitted in ready-to-eat foods that have been kept properly refrigerated. Its ability to grow in such diverse environments is just one of the many challenges presented by this dangerous bacterium.
It is estimated that Listeria causes approximately 1,600 cases of listeriosis annually, resulting in 415 deaths.
