1. Department of Pediatrics, 2nd Faculty of MedicineCharles University and Motol University Hospital Prague Czech Republic
2. Department of Probability and Mathematical Statistics, Faculty of Mathematics and PhysicsCharles University Prague Czech Republic
3. Department of Pediatrics, 3rd Faculty of MedicineCharles University and Kralovske Vinohrady University Hospital Prague Czech Republic
4. Institute of Microbiology of the Czech Academy of Sciences Prague Czech Republic