Mutant candidate for TB vaccine

HIV and the emergence of drug resistant mycobacteria have once again elevated tuberculosis to disease of worldwide importance but, with the possible exception of bacille Calmette-Guerin (BCG), there is currently no vaccine against this disease. In September 9 Nature Medicine, Vasan Sambandamurthy and colleagues at the Albert Einstein College of Medicine, New York, describe a pantothenate auxotroph of Mycobacterium tuberculosis that is highly attenuated and protects mice against tuberculosis (Nat Med 2002, DOI:10.1038/nm765).

Sambandamurthy et al. constructed a double-deletion mutant of M. tuberculosis, removing the panC and panD genes that are involved in the de novo biosynthesis of pantothenic acid (vitamin B5). They observed that this mutant is highly attenuated in SCID mice. Mice infected with the ∆panCD mutant survived significantly longer (250 days) than mice inoculated with either the BCG vaccine or a virulent M. tuberculosis strain (77 and 35 days, respectively – P < 0.05). In addition, subcutaneous ...