1. Departamento de Microbiología y Genética, Campus Miguel de Unamuno, University of Salamanca, 37007 Salamanca, Spain
2. Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Victoria, Australia
3. Instituto de Investigación Biomédica de Salamanca (IBSAL), Complejo Asistencial Universitario de Salamanca, CSIC, Salamanca, Spain
4. Department of Biochemistry and Molecular Biology, University of Salamanca, Salamanca, Spain
5. School of Natural and Environmental Sciences, Ridley Building, Newcastle University, Newcastle upon Tyne NE1 7RU, UK