1. Department of Microbiology and Immunology, University of Louisville, Louisville, USA
2. King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
3. Present address: King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
4. Dental School, University of Louisville, Louisville, Kentucky, USA
5. Center for Predictive Medicine, University of Louisville, Louisville, USA