1. Department of Restorative Dentistry, Oregon Health and Science University, Portland, Oregon, USA
2. Department of Pediatric Dentistry, Oregon Health and Science University, Portland, Oregon, USA
3. Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Giza, Egypt
4. Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon, USA