1. Infectious Diseases Unit, Department of Medical and Surgical Sciences, Sant’Orsola-Malpighi Hospital, University of Bologna, Bologna
2. Clinical Epidemiology Unit, IRCCS Policlinico San Matteo Foundation Pavia, Italy
3. Infectious Diseases Unit, Rimini-Forlì-Cesena Hospitals, Rimini, Italy
4. Operative Unit of Clinical Microbiology, St Orsola-Malpighi University Hospital, Bologna, Italy