1. Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35233, USA.
2. Division of Genetic Engineering, National Research Center of Egypt, Cairo, Egypt.
3. Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
4. Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35233, USA.
5. Institute for Mathematical Modeling of Biological Systems, Department of Biology, University of Düsseldorf, Düsseldorf, Germany.