1. Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Madrid, Spain
2. Public Health Networking Biomedical Research Centre in Epidemiology and Public Health (CIBERESP), Madrid, Spain
3. Public Health Networking Biomedical Research Centre in Infectious Diseases (CIBERINFEC), Madrid, Spain
4. Department of Biology, Emory University, Atlanta, Georgia, USA