Evolution of Drug Resistance in Mycobacterium and Newer Approaches towards Effective Treatment of Tuberculosis

Genus Mycobacterium comprises a group of pathogenic, non-pathogenic and environmental bacteria. The extensive host range of this genus is a remarkable characteristic. Mycobacterium avian complex has a close relationship with nonpathogenic groups and plays a significant role in the evolutionary study of these bacteria. Tuberculosis, a noxious bacterial disease caused by M. tuberculosis, has infected a large section of the population throughout the world, including India. M. tuberculosis is the most successful pathogen of this genus that invades the host as a parasite and survives within the macrophages of its host’s immune-cell lineage. Tuberculosis is of prime concern to clinicians as the development of drug resistance is a common phenomenon of this pathogen. Treatment of patients particularly infected with the multi-drug-resistant and extensively drug-resistant strains are very difficult with the available pool of antibiotics. Some alternative strategies, like the use of novel phytochemicals, synthetic nano-drugs, etc., have proven promising to treat the drugresistant strains.