1. Department of Medical Microbiology and Immunology “Prof. Dr. Elissay Yanev”, Faculty of Pharmacy, Medical University of Plovdiv, 4002 Plovdiv, Bulgaria
2. Laboratory of Microbiology, University Hospital St. George, 4000 Plovdiv, Bulgaria
3. Research Institute, Medical University of Plovdiv, 4002 Plovdiv, Bulgaria
4. Department of Pathology, Zealand University Hospital, 4000 Roskilde, Denmark
5. Clinic of Vascular Surgery, University Hospital St. George, 4000 Plovdiv, Bulgaria
6. National Reference Laboratory of Enteric Infections, Pathogenic Cocci and Diphtheria, Department of Microbiology, National Center of Infectious and Parasitic Diseases, 1504 Sofia, Bulgaria