Listeria contamination of foods is a major concern of the food industry and public health authorities, and work continues to be done to combat it through research and development, regulatory guidance, and educational programs. Of the six species of bacteria in the genus Listeria, Listeria monocytogenes is the primary species associated with foodborne illness. It causes a noninvasive gastrointestinal illness (listerial gastroenteritis) and a more serious invasive illness (listeriosis), which may …