Researchers from the CEU Cardenal Herrera University (CEU UCH) of Valencia, the University of Cordoba and the Pasteur Institute of Paris have conducted a study to determine the virulent potential of strains of the listeria monocytogenes bacteria in pigs in Spain. These animals are asymptomatic reservoirs for this bacteria, which both in humans as well as animals causes the disease known as listeriosis, an infection that is increasing in cases in the EU since 2008. "The current health safety controls prevent the consumption of products that could be contaminated, but finding the virulent strains we have detected in these animals will improve the control and monitoring of the bacteria," says Juan José Quereda, lecturer and researcher at the CEU UCH, who has headed the study.