1 1Department of Pathobiology and Medical Biotechnologies, Section of General Pathology, University of Palermo, Corso Tukory 211, 90134 Palermo, Italy.
2 2Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC 29425 USA.
3 3Department of Medicine and Surgery, University of Salerno, Baronissi, Italy.