1. Departments of Medicine,1
2. College of Medicine, Medical University of South Carolina, Charleston, South Carolina 294252; and
3. Institute of Infectious Diseases and Public Health, University of Ancona, Ospedale Umberto I, 60121 Ancona, Italy3
4. Genetics,4
5. Microbiology,5
6. Pharmacology and Cancer Biology,6 and
7. Howard Hughes Medical Institute,7 Duke University Medical Center, Durham, North Carolina 27710;