Alexandre Leclercq is deputy director of the French Reference Centre and WHO Collaborating Centre for Listeria and on-call biologist at the Laboratory for Urgent responses to biological threats at Institut Pasteur, Paris. Chemical and agricultural engineer (ISAB, France; Catholic University of Louvain (UCL), Belgium), he spent three years at UCL as assistant professor in microbiology and chemistry where he studied molecular epidemiology of Shiga toxin-producing Escherichia coli. Then, he became deputy director of education department and head of laboratory for Food Safety and Microbiology at Institut Pasteur Lille. In 2003, he joined Institut Pasteur at Paris and at first studied molecular epidemiology of enteropathogenic Yersinia and plague and, in 2007, national and international microbiological surveillance, epidemiology and genomic of Listeria and urgent responses to biological threats. After thirteen years of standardization at CEN and ISO level, he was nominated in 2005 convenor of CEN TC275 “Food Analysis” Working Group 6 “Microbiology of the food chain” and since 2011 scientifically manage the CEN mandate M381 of European Commission on validation of fifteen reference CEN ISO methods in microbiology of the food chain. He is technical assessor in food/water/environmental/medical microbiology, proficiency testing and molecular biology at civil and military level for four accreditation bodies.