1. Wageningen Centre for Food Sciences (WCFS), and, Laboratory of Microbiology, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands.
2. Wageningen Centre for Food Sciences (WCFS), and, NIZO Food Research, PO Box 20, 6710 BA Ede, The Netherlands.
3. Wageningen Centre for Food Sciences (WCFS), and, Department of Basic Veterinary Sciences, Helsinki University, F1-00014 Helsinki, Finland and, Laboratory of Microbiology, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands.