1. Laboratory of Medical Microbiology, University of Insubria and Ospedale di Circolo, Varese
2. Department of Pathology and Laboratory Medicine, Section of Microbiology, University of Parma, Parma
3. Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome
4. Laboratory of Microbiology, Azienda Policlinico, University of Catania, Catania
5. Department of Microbiological and Gynecological Sciences, Section of Microbiology, University of Catania, Catania, Italy