Listeriosis is a zoonotic disease of food origin that can cause, both in the human species and in animals, symptoms of gastroenteritis, meningitis, bacteremia and miscarriages. The pathogen that causes this infection is the Listeria bacteria. Juan José Quereda, researcher with a Ramón y Cajal contract and professor at the CEU Cardenal Herrera University (CEU UCH), where he leads the research group on Intracellular Pathogens, has been conducting research in this field since 2011.