1. National Institute for Environmental Health, Department of Water Hygiene – Albert Flórián út 2–6, H-1097 Budapest, Hungary
2. Semmelweiss University, Infection Control Unit – Nagyvárad tér 4, H-1089 Budapest, Hungary
3. National Center for Epidemiology, Department of Phage-typing and Molecular epidemiology – Albert Flórián út 2-6, H-1097 Budapest, Hungary
4. Semmelweiss University, Kútvölgyi Teaching Hospital – Kútvölgyi út 4, H-1125 Budapest, Hungary