Mycobacteria of the intracellulare-scrofulaceum group in soils from the Adelaide area.

Soil samples from the Adelaide area--where organisms belonging to the Mycobacterium intracellulare-scrofulaceum (MIS) group are rarely encountered in sputum of persons under investigation of pulmonary mycobacterial disease--were examined for the MIS group. Thirty-one per cent were positive for MIS organisms and 17% were positive for MIS serotypes known to be disease-associated. Comparison with an earlier study of soils from the Brisbane area--where this group of organisms is frequently isolated from sputum of persons under investigation for pulmonary mycobacterial disease--suggests that the disease-associated MIS serotypes are significantly more common in the environment of the Brisbane area. This implies a positive correlation, and consolidates existing evidence that the environment is the reservoir of, and a source of infection with, organisms of the MIS group.