1. Department of Clinical and Molecular Biomedicine, Division of Infectious Diseases, University of Catania, Via Palermo 636, 95125 Catania, Italy
2. Department of Microbiology, University of Catania, 95100 Catania, Italy
3. Department of Surgery, Transplantation and Advanced Technologies, General Surgery Unit, University of Catania, 95100 Catania, Italy