1. Infectious Disease Unit, 3rd Department of Pediatrics, Medical Faculty, Aristotle University School of Health Sciences, Hippokration General Hospital, Thessaloniki, Greece.
2. Microbiology Department, Hippokration General Hospital, Thessaloniki, Greece.
3. Infection Control Committee, Hippokration General Hospital, Thessaloniki, Greece.
4. Pediatric Intensive Care Unit, Hippokration General Hospital, Thessaloniki, Greece.
5. Microbiology Department, National and Kapodistrian University School of Medicine, Athens, Greece.