1. Department of Medical-Surgical Sciences and Public Health, Faculty of Medicine and Surgery, University of Perugia, Loc. S. Andrea delle Fratte, 06156 Perugia, Italy
2. Department of Biopathological Science and Hygiene of Food and Animal Production, Faculty of Veterinary Medicine, University of Perugia, Via San Costanzo 4, 06126 Perugia, Italy