1. Department of Infectious Microbiology, The Stephan Angeloff Institute of Microbiology Bulgarian Academy of Sciences, Sofia, Bulgaria;
2. Department of Applied Microbiology, The Stephan Angeloff Institute of Microbiology Bulgarian Academy of Sciences, Sofia, Bulgaria;
3. Department of Pharmacology Pharmacotherapy and Toxicology Faculty of Pharmacy, Medical University of Sofia, Sofia, Bulgaria;
4. Toxicology and Chemotherapy Unit, German Cancer Research Center, Heidelberg, Germany;
5. Department of Pharmaceutical Technology and Biopharmaceutics Faculty of Pharmacy, Medical University of Sofia, Sofia, Bulgaria