1. Laboratory of Clinical Microbiology, Attikon University General Hospital, National and Kapodistrian University, Athens, Greece
2. Immunocompromised Host Section, Pediatric Oncology Branch, National Cancer Institute, Bethesda, Maryland
3. Department of Microbiology, Medical School, University of Thessaly, Larissa, Greece
4. Third Department of Pediatrics, Aristotle University, Hippokration Hospital, Thessaloniki, Greece