1. Health Protection Agency North West region (HPA NW), Liverpool, United Kingdom
2. Health Protection Scotland (HPS), Glasgow, United Kingdom
3. Scottish Salmonella, Shigella and Clostridium difficile Reference Laboratory, Glasgow, United Kingdom
4. Health Protection Agency Food Water and Environmental Microbiology Laboratory, Preston, United Kingdom
5. Health Protection Agency East of England region, Witham, Essex, United Kingdom
6. Health Protection Agency Gastrointestinal, Emerging and Zoonotic Infections Department (GEZI) - Epidemiological Services, London, United Kingdom
7. Food Standards Agency, London, United Kingdom