1. Department of Physics and NTIS – European Centre of Excellence, University of West Bohemia, Univerzitní 8, 306 14 Plzeň, Czech Republic and National Research Tomsk Polytechnic University, 30 Lenin Avenue, 634050 Tomsk, Russia
2. Department of Physics and NTIS – European Centre of Excellence, University of West Bohemia, Univerzitní 8, 306 14 Plzeň, Czech Republic
3. Department of Microbiology, Medical Faculty in Plzeň, Charles University in Praha, E.Beneše 13, CZ-30599 Plzeň, Czech Republic