Janet R. Donaldson
Listeria monocytogenes is a gram-positive bacillus and is the causative agent of listeriosis. Approximately 2500 cases of listeriosis and 500 deaths are reported each year, making it the deadliest food borne pathogen. The CDC has reported that the incidence of L. monocytogenes has decreased by 36% between 1996 and 2006. However, outbreaks still occur, making it a cause for concern among the medical and food industries.