1. Division of Infectious Diseases, Department of Clinical and Molecular Biomedicine, Garibaldi Nesima Hospital, University of Catania, 95125 Catania, Italy
2. Division of Otorhinolaryngology, Department of Medical-Surgical Specialties, Policlinico-Vittorio Emanuele Hospital, University of Catania, 95125 Catania, Italy
3. Division of Pathology and Experimental Microbiology, Elie Metchnikoff Department, University of Messina, 98125 Messina, Italy