1. Laboratory of Cellular Immunology, Department of Microbiology, Hellenic Pasteur Institute, 127 Vass Sofias Av, 11521 Athens, Greece
2. Department of Microbiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece
3. Laboratory of Molecular Epidemiology and Experimental Pathology, Institut Pasteur de Tunis/Université de Tunis el Manar, 13 Place Pasteur, BP 74, 1002 Tunis-Belvédère, Tunisia