Resistance to antimicrobial agents in Mycobacterium tuberculosis.

According to the World Health Organization (WHO) more people will currently die of tuberculosis (TB) than in any other year in history. Of equal concern are the emergence and nosocomial transmission of multidrug-resistant (MDR) strains of Mycobacterium tuberculosis. Only recently, with the advent of new molecular biological techniques, the mechanisms of drug resistance in TB bacilli are more and more understood. In M. tuberculosis, the primary mechanism of drug resistance seems to be exclusively confined to chromosomal DNA and not, as in other bacteria, to mobile genetic elements as well.