Pediatric Infections Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Students Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran. Clinical Microbiology Research Center, Ilam University of Medical Science, Ilam, Iran. Food Safety and Hygiene Division, Environmental health Department, School of Public Health, Tehran University of medical sciences, Tehran, Iran. Students Research Committee, Department of Food Sciences and Technology, Faculty of Nutrition and Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran. Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Department of Medical Microbiology, School of Medicine, Ilam University of Medical Science, Ilam, Iran.