1. Department for Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
2. Chemical and Veterinary Analysis Agency Stuttgart (CVUAS), Fellbach, Germany
3. Laboratorio de Referencia de Escherichia coli (LREC), Dpto. de Microbioloxía e Parasitoloxía, Universidade de Santiago de Compostela (USC), Lugo, Spain
4. Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), Santiago, Spain
5. Department for Farm Animals and Veterinary Public Health, Unit of Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Vienna, Austria