1. Institute of Microbiology of the Czech Academy of Sciences, CZ-142 20 Prague, Czech Republic
2. Department of Health Care and Population Protection, Faculty of Biomedical Engineering, Czech Technical University in Prague, CZ-272 01 Kladno, Czech Republic
3. Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Technická 5, CZ-166 28 Prague, Czech Republic