Drug targets in dormant Mycobacterium tuberculosis: can the conquest against tuberculosis become a reality?

Targeting M. tuberculosis (Mtb) in latent form of infection is a major obstacle and big challenge in tuberculosis (TB) eradication by current chemotherapy. A better understanding of the physiology of Mtb and of the metabolic state of the bacillus during the dormancy, is a primary need in finding drug targets against non replicating persistent (NRP) form of the Mtb. Identification of potential drug targets against dormant state of Mtb is critically important to achieve the goal of complete eradication for shortening of anti-TB therapy. The metabolic processes functioning in dormant Mtb in providing cell viability and protecting Mtb from sterilization by the hostile environment can be explored as drug targets. This review discusses about the potential drug targets in dormant tubercle bacilli, anti-dormancy inhibitors and the strategies which can be pursued for maximizing success if these targets are exploited for killing the dormant bacilli. This has important implications as the currently available arsenal of drugs suffers from the demerit of achieving sterilizing killing of mycobacteria. This lacuna can be overcome if the proposed strategies for eliminating dormant bacteria are combined along with the existing treatment modalities for the extirpation of bacilli.