Pathogenesis of nontuberculous mycobacteria infections

Infections caused by nontuberculous mycobacteria (NTM) species are being increasingly identified. Mycobacteria such as Mycobacterium kansasii, Mycobacterium chelonae, Mycobacterium fortuitum, Mycobacterium avium, and Mycobacterium intracellulare are responsible for the great majority of the infections by NTM. The syndromes associated with the infection range from chronic localized disease to potentially fatal entities. A few of the pathogenic mechanisms of M avium and M intracellulare, as well as,W kansasii, are now beginning to be described. This article presents a summary of what is currently known about pathogenic mechanisms of M kansasii, M chelonae, M avium., and M intracellulare infections.