G Meletis1, D Chatzidimitriou2. 1. Labnet laboratories, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece. 2. Labnet laboratories, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece; Laboratory of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.