1. A′ Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
2. Department of Medical Parasitology, Institute for Medical Research, University of Belgrade, Belgrade, Serbia.
3. Department of Control of Infectious Diseases, Institute of Public Health, Tirana, Albania.
4. Veterinary Research Institute of Thessaloniki, National Agricultural Research Foundation (NAGREF), Thessaloniki, Greece.