1. Department of Microbiology, National Centre for Infectious and Parasitic Diseases, Sofia, Bulgaria
2. Department of Clinical Laboratory, Laboratory of Microbiology, University Multidisciplinary Hospital for Active Treatment, Stara Zagora, Bulgaria
3. Department of Paediatric Infectious Diseases, University Hospital Professor Ivan Kirov, Medical University of Sofia, Sofia, Bulgaria
4. Department of Radiology, UMBAL, Stara Zagora, Bulgaria