Résumé : The annual seminar of the Translational Research Committee of the French Intensive Care Society is aimed at bringing together physicians and scientists to answer relevant research questions in the field of intensive care medicine. The fourth edition of the meeting was related to infectious diseases, and focused on various concerns in critically ill patients, including host-pathogen relationships, the potential role of pathogens in diseases classically viewed as non-infectious, emerging infectious threats, technological advances in the molecular diagnosis of infections, and the development of alternative anti-bacterial strategies besides classical antibiotic chemotherapy.