1. Department of Medical Biotechnologies, University of Siena, Siena, Italy
2. Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
3. Department of Surgery and Translational Medicine, University of Florence, Florence, Italy
4. Infectious Diseases Division, Santa Maria della Misericordia University Hospital, Udine, Italy
5. Clinical Microbiology and Virology Unit, Florence Careggi University Hospital, Florence, Italy