1. Novartis Institute for Tropical Diseases 10 Biopolis Road, #05‐01 Singapore 138670 Singapore
2. Department of Microbiology Yong Loo Lin School of Medicine National University of Singapore 5 Science Drive 2 Singapore 117597 Singapore
3. Tuberculosis Research Section National Institutes of Health Bldg: 33, 33 North Drive Bethesda MD 20892 USA