The molecular basis of resistance to isoniazid, rifampin, and pyrazinamidein Mycobacterium tuberculosis

Multidrug-resistant (MDR) strains of Mycobacterium tuberculosis have emerge d worldwide. In many countries and regions, these resistant strains constit ute a serious threat to the efficacy of tuberculosis control programs. An i mportant element in gaining control of this epidemic is developing an under standing of the molecular basis of resistance to the most important antitub erculosis drugs: isoniazid, rifampin, and pyrazinamide. On the basis of thi s information, more exacting laboratory testing, and ultimately more approp riate and timely treatment regimens, can be developed.