[Atypical mycobacterioses. Unusual pathogens of increasing significance].

Atypical mycobacteria may cause pulmonary diseases - similar to tuberculosis - as well as infections of the lymph nodes, the skin and other organs. But only if several cultures from sputum or biopsy specimen have been positive and Mycobacterium tuberculosis has been excluded, these species can be noted as the pathogenetic agents. The course of disease mostly times appears uncharacteristic, the manifestations remind of chronic tuberculosis. The majority of patients with atypical mycobacterioses belong to the group with reduced host resistance (like AIDS, immunosuppression, malignancy). The outcome and prognosis without special treatment are deleterious. Because of the difference in the susceptibility of atypical mycobacteria to antituberculotic drugs a successful chemotherapy only can be made according to the analysis of resistance behaviour.