[Mycobacterioses].

Mycobacteriosis are opportunistic infections caused by atypical mycobacteria. These have microscopic features resembling those of tubercle bacillus but differ in their cultural and biochemical characteristics and above all, their resistance to antituberculous antibiotics. The lesions chiefly involve the lungs, the lymph nodes or the skin and usually mimick those of tuberculosis. The diagnosis rests on repeated isolation in pathological specimens of the same atypical mycobacterium with a sufficient number of colonies, or on its sole presence in effusion fluids, biopsies or surgical specimens. Treatment with antibiotics is disappointing, except for M. kansasii. Surgical treatment can only be considered in those exceptional cases when the patient is young, has limited lesions and is not immuno-depressed.