1. Student’s Scientific Association of General Paediatrics, Department of Paediatrics and Nephrology, Medical University of Warsaw, Warsaw, Poland
2. Department of Dental Microbiology, Microbiology Laboratory UCML, UCK WUM, Warsaw, Poland
3. Laboratory of the Józef Polikarp Brudziński Children’s Clinical Hospital in Warsaw, Medical University of Warsaw, Warsaw, Poland
4. Department of Paediatrics and Nephrology, Medical University of Warsaw, Warsaw, Poland