1. University of Wuppertal, Department of Applied Physiology, Occupational Medicine and Infectiology Faculty of Safety Engineering, Wuppertal
2. University of Hohenheim, Faculty of Agricultural Science, Stuttgart-Hohenheim
3. University of Kassel, Faculty of Ecological Agricultural Science, Department of Animal Nutrition and Animal Health, Kassel-Witzenhausen, Germany
4. Mikrobiologisches Labor Dr. J. Balfanz- Dr. M. Lohmeyer GbR, Microbiological Laboratory, Münster, Germany