[1] Gloucestershire Royal Hosp, Hlth Protect Agcy, Primary Care Unit, Gloucester GL1 3NN, England
[2] Gloucestershire Hosp NHS Fdn Trust, Endoscopy Unit, Gloucester, England
[3] Hlth Protect Agcy, Stat Unit, London, England
[4] Publ Hlth Wales Microbiol Bangor, Bangor, Gwynedd, Wales
[5] HPA, Lab Gastrointestinal Pathogens, Helicobacter Reference Unit, London, England
[6] Univ Hosp Freiburg, Inst Med Microbiol & Hyg, Freiburg, Germany