1. National Reference Centre for Listeriosis (CNRL), Lausanne Switzerland
2. Swiss Federal Office of Public Health (SFOPH), Bern, Switzerland
3. Institut Neuchâtelois de Microbiologie, La Chaux-de-Fonds, Switzerland
4. Service cantonal de la santé publique, Neuchâtel, Switzerland
5. Service de la consommation, Neuchâtel, Switzerland
6. Hôpitaux Canton de Neuchâtel, Switzerland
7. COOP, Central laboratory, Switzerland