1. Department of Pathology and Laboratory Medicine, Section of Microbiology, University of Parma, Viale A. Gramsci, 14-43100 Parma, Italy
2. Department of Experimental and Applied Medicine, Institute of Microbiology, Spedali Civili, University of Brescia, Piazza Spedali Civili, 1-25123 Brescia, Italy
3. Arcispedale S. Maria Nuova, Centrale Operativa, Viale Risorgimento, 57-42100 Reggio Emilia, Italy
4. Parasitologie Comparée et Modèles Expérimentaux (Unité Scientifique Muséum 0307), Centre National de la Recherche Scientifique Institut Fédératif de Recherche 101, Muséum National d'Histoire Naturelle, CP52, 61 Rue Buffon 75231 Paris Cedex 05, France