1. Internal Medicine, Angiology and Arteriosclerosis Section, Department of Clinical and Experimental Medicine, University of Perugia Medical School, Hospital ‘Santa Maria della Misericordia’, Piazzale Menghini 1, I-06129 Perugia, Italy
2. Microbiology Section, Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy