[Listeria monocytogenes infections].

Listeria monocytogenes infections are caused by food ingestion. They are not only transmitted by animal products, but also by secondarily contaminated fruits and vegetables. They preferentially affect pregnant women, patients of extreme ages and the immu-nocompromised, and manifest as a gastroenteritis, bacteremia, meningo-encephalitis or maternal-fetal infection. Diagnosis is achieved by culture of usually sterile sites. The preferred treatment is amoxicillin with or without gentamicin. For patients at risk, prevention is based on avoiding at-risk food or cooking it when possible.