Current strategies for identifying and validating targets for new treatment-shortening drugs for TB.

There is an urgent need for new drugs to treat tuberculosis. During the last forty years the only drugs to have been developed are variations on existing ones, but new drug candidates must offer improvements over existing agents. In particular, we require new drugs having novel mechanisms of action that are active against drug-resistant strains and also kill persistent bacilli, thus shortening the length of chemotherapy. Recent advances in our understanding of the biology of Mycobacterium tuberculosis, in particularly the availability of the genome sequence coupled with development of new genetic tools, have greatly contributed to the discovery of potential drug targets for new antituberculars. However, although many potential new drug targets have been identified, greater effort is required in target validation to show properly that they are essential for bacterial growth and survival. In this review, the current drug development pipeline and the strategies employed to identify and validate novel tuberculosis drug targets are presented.