1. Northern Ireland Working Group on Nebuliser Care and Hygiene in Cystic Fibrosis, Belfast, Northern Ireland.
2. Northern Ireland Paediatric CF Centre, Department of Physiotherapy, Royal Belfast Hospital for Sick Children, Belfast, Northern Ireland.
3. Department of Medical Microbiology, Royal Group of Hospitals, Belfast, Northern Ireland.
4. Northern Ireland Public Health Laboratory, Department of Bacteriology, Belfast City Hospital, Lisburn Road, Belfast, Northern Ireland.