[Nontuberculous mycobacteria: clinically relevant].

The nontuberculous or atypical mycobacteria (NTM) are a group of largely opportunistic pathogens, which are increasingly being detected in patients and being associated with clinical disease. Various host factors are responsible for this, such as the ageing population with the accompanying increase in the number of patients with chronic diseases, but NTM are also detected more often as a result of improvements in diagnostic laboratory techniques. The clinical relevance, i.