1. Neonatal Intensive Care Unit, “Agios Panteleimon” General Hospital of Nikea, 18454 Piraeus, Greece
2. Neonatal Department, National and Kapodistrian University of Athens, Aretaieio Hospital, 11528 Athens, Greece
3. Microbiology Department, “Saint Savvas” Oncology Hospital, 11522 Athens, Greece
4. Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, 20090 Milan, Italy
5. IRCCS Humanitas Research Hospital, Rozzano, 20089 Milan, Italy
6. Laboratory of Haematology and Blood Bank Unit, “Attiko” Hospital, School of Medicine, National and Kapodistrian University of Athens, 12462 Athens, Greece