Bacillus cereus sensu lato includes four members displaying marked differential virulences: the commensal Bacillus mycoïdes, the food-contaminant Bacillus cereus, the entomopathogenic Bacillus thuringiensis and the lethal Bacillus anthracis. This study aims at 1) establishing the prevalence and diversity of potential virulence factors among these bacteria, 2) correlating some of these factors with specific pathogenesis, 3) in order to assess the risks associated with these bacteria.