Department of Internal Medicine, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran., Tara Nazari, Amir Rostami, Department of Internal Medicine, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran., Bahar Nayeri Fasaei, Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran., Hesameddin Akbarein, Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran., Iraj Ashrafi Tamaei, Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.