1. Department of Biological, Geological and Environmental Sciences, University of Catania, Via Androne 81, 95124 Catania, Italy
2. Experimental Zooprophylactic Institute of Sicily “A. Mirri”, Via Gino Marinuzzi, 3, 90129 Palermo, Italy
3. Department of Chemical Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy