Listeria monocytogenes: incidence on vegetables

Abstract Listeria monocytogenes is widely distributed on plant vegetation, including raw vegetables. Its presence on plant materials is likely due to contamination from decaying vegetation, animal faeces, soil, surface, river and canal waters, or effluents from sewage treatment operations. The organism is known to survive in plant materials for 10–12 years. The presence of L. monocytogenes on many types of raw and minimally processed vegetables destined for human consumption has been clearly demonstrated in many countries but the role these vegetables play as vehicles for human infection is not known. It is certain, however, that if consumers are to continue to benefit from the essential contribution raw and minimally processed vegetables make to their nutritional well-being, they will also very likely continue to consume vegetables containing low numbers of L. monocytogenes.