1. Departamento de Biotecnología, Centro Nacional INIA, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
2. Department of Microbiology and Immunology, University of Rochester, Rochester, New York, USA
3. Animal Health Research Centre (CISA), National Institute for Agriculture and Food Research and Technology (INIA-CSIC), Valdeolmos, Madrid, Spain
4. Texas Biomedical Research Institute, San Antonio, Texas, USA