1. Columbia University College of Physicians and Surgeons,
2. Department of Pediatrics, Columbia University, and
3. Department of Pediatrics and
4. Department of Microbiology, New York University School of Medicine, New York, New York;
5. Department of Microbiology and Immunology and
6. Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore; and
7. Department of Obstetrics and Gynecology, Weill Cornell Medical College, New York, New York