Environmental mycobacteria in Korea. I. Distribution of the organisms.

Environmental mycobacteria in Korea have been investigated by examining 54 soil, 111 house dust, 63 well water, and 98 sewage samples collected from 123 randomly selected areas in Korea during the fourth nationwide tuberculosis prevalence survey in 1980. A variety of mycobacteria were isolated from 76% of soil, 67% of sewage, 43% of well water, and 7% of house dust samples. Some samples yielded more than one species; thus 56 strains were obtained from soil, 107 strains from sewage, 48 strains from well water and 8 strains from house dust. Mycobacterium fortuitum was the most common species of environmental mycobacteria in Korea and the species was distributed equally in all types of samples tested. The M. terrae complex was also one of the common species of environmental mycobacteria and it seemed to be more abundant in water samples than in soil. Scotochromogenic slow growers M. scrofulaceum and M. gordonae were common microbes in soil and water samples, although the latter was more frequently detected in water samples. Scotochromogenic rapid growers M. flavescens and M.phlei, and photochromogenic rapid grower M. vaccae were isolated more frequently from sewage or water samples than from soil. Nonphotochromogenic rapid growers M. chelonei (chelonae) and M. smegmatis were isolated mostly from sewage and the former was rarely found in soil and well water samples. The clinically important species M. avium-intracellulare complex was found less frequently in all types of test samples.