He was born in Madrid, he graduated in Medicine and Surgery at the Complutensis University in Madrid, and received his Ph.D. in Medical Microbiology (1973) from the Autonomous University of Madrid. He was trained at the National Hospital for Infectious Diseases in Madrid, at Max von Pettenkofer Institute in Munich, Pasteur Institute in Paris, and Emory University (1995). Scientific Director of the Ramón y Cajal Health Research Institute (IRYCIS) (2008-2015). He was Senior Scientist in Evolutionary Biology at the Center for Astrobiology (CAB, INTA-NASA associated). From 2008 to date, Research Professor in Microbial Evolution and, and Director of the Division of Microbial Biology and Evolution of Microorganisms. Founder member of APUA (Alliance for the Prudent Use of Antibiotics), he also served as Member of the ICAAC Program Committee, Member of EARSS Scientific Committee, President of the ESCMID Group for Surveillance of Antimicrobial Resistance, and has been President of the European Congress for Clinical Microbiology and Infectious Diseases; Focal Point Scientist of the ECDC, Member of the Scientific Advisory Board of the EC Joint Programming Initiative on Antimicrobial Resistance. He received several international honors and awards, including the Excellence Awards of the American ASM-ICAAC, Award of Excellence of European Society for Clinical Microbiology and Infectious Diseases, Garrod Medal of the British Society for Antimicrobial Chemotherapy, Descartes Award of the EU Commission for International Collaborative Research, Medal and Honorary ISC Membership of the International Society for Chemotherapy, Excellence Award of the Spanish Society of Microbiology, Lilly Foundation Award to Distinguished Scientific Carrier, Honorary Member of the Spanish Society for Evolutionary Biology, FENIN Award to Technological Innovation in Health, Lwoff Award and Medal of the European Federation of Microbiological Societies (2015), and Arima Award for Applied Microbiology of the International Union of Microbiological Societies (2017).
His research interests focus on the biochemistry, genetics, population biology, epidemiology, ecology, and evolutionary biology of antibiotic resistance and virulence, and particularly on the multi-level processes influencing selection of resistant microbes, and the possibilities of applying control interventions and therapies. On these and related topics, he published 758 research publications (Research Gate), 490 of them referred in PubMed, has a H-index of 100 and i10 index of 391 (Google Scholar), with more 35,000 citations. As side-interests, he has also published in the fields of philosophy of science, particularly in epistemology of complex biological systems.