1. Food Safety Microbiology Laboratory, Division of Gastrointestinal Infections, Public Health Laboratory Service, Central Public Health Laboratory, London NW9 5HT
2. School of Chemical and Life Sciences, University of Greenwich, Woolwich, London SE18 8PF
3. Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 2QH
4. Public Health Laboratory, Glan Clwyd District Hospital, Rhyl, Denbighshire LL18 5UJ
5. Bro Taf Health Authority, Temple of Peace and Health, Cathays Park, Cardiff CF1 3NW, United Kingdom