STUDIES ON SOIL ACID-FAST BACILLI Part 1. The Distribution and the Biological Charadcristies of Soil Acid-Fast Bacilli.

Abstract

In order to observe the distribution of the unclassified mycobacteria in the soil, various origins of soil sample were cultured for the detection of mycobacteria and the isolated strains were studied as follows: 1. Among 210 soil samples, 45 strains(21.4%) were isolated by direct method, and 88 strains(41.9%) by indirect method respectively. 2. No remarkable difference was noted in isolation ratio according to the source of soil samples. 3. According to Runyon's schema, 133 isolated strains were classified as follows: photochromogen 1(0.75%) scotochromogen 26(19.5%) non-photochromogen 12(9.0%) rapid grower 94(70.7%) 4. Out of the 133 isolated strains, 47 were pigmented strain and among the pigmented strains 37 were slow grower. 5. All of the isolated strains exhibited strong positive catalase reaction and the growth characteristics on various media were diverse patterns, however, non-pigmented rapid grower were usually more active grower on the media tested. 6. The range of growth temperature of the slow grower was between 22℃ to 37℃, whereas, the range of rapid grower was up to 42℃ or above. 7. Acid fastness of the pigmented strains were generally stronger than rapid grower but weaker than tubercle bacilli. 8. Among the pigmented strains, five strains formed cord. Five strains were neutral red test positive and three strains were niacin test positive. 9. pigmented strains were generally more sensitive to tuberculous agents than non-pigmented ones.