1. Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Assiut, Egypt
2. Department of Tropical Medicine and Gastroenterology, Faculty of Medicine, Assiut University Hospital, Assiut, Egypt
3. Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut, Egypt
4. Department of Internal Medicine, University of Cincinnati Medical Center, Cincinnati, OH, USA