1. Regional Reference Laboratory of Clinical and Environmental Surveillance of Legionellosis, Department of Medical and Surgical Sciences and Advanced Technologies “G.F. Ingrassia”, University of Catania, Via Sofia 87, 95123 Catania, Italy
2. Azienda Ospedaliero Universitaria Policlinico “G. Rodolico-San Marco”, Via S. Sofia 78, 95123 Catania, Italy
3. Infectious Diseases and Infection Prevention Department, University of Pittsburgh, School of Medicine and Public Health Pittsburgh, Pittsburgh, PA 15213, USA