1. Department of Medical Biotechnologies, University of Siena, Siena, Italy
2. Present address: Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
3. Present address: Don Carlo Gnocchi Foundation, Florence, Italy
4. Present address: Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy
5. Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
6. Don Carlo Gnocchi Foundation, Florence, Italy
7. Clinical Microbiology and Virology Unit, Florence Careggi University Hospital, Florence, Italy