1. Department of Food Safety and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
2. Department of Animal Pathology, Faculty of Veterinary Medicine, Turin, Italy
3. Istituto Zooprofilattico Sperimentale della Sicilia, Barcellona Pozzo di Gotto, Italy
4. Veterinary Service of Azienda Sanitaria Locale, Catania, Italy