1. Department of Microbiology, New York University School of Medicine, New York, New York
2. Department of Medicine, New York University School of Medicine, New York, New York
3. Departments of Medicine and Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee
4. University of Hawaii, Honolulu, Hawaii
5. Division of Gastroenterology, Vanderbilt University School of Medicine, Nashville, Tennessee