Abstract
A genetic study was made on the streptomycin-resistance system of Mycobacterium tuberculosis var. hominis (strains H37 Rv and Aoyama-B) and the following conculusions were obtained.
Survival curves of the organism for streptomycin were discontinuous at two points, at a point between 2 and 5mcg and at another point between 20 and 50mcg under the conditions tested and it has been therefore suggestd that there are three genotypes determining streptomycin-resistance; sensitivity, lower resistance, and higher resistance.
A phenomenon of interference between sensitive cells and resistant mutants as an agent suppressing the growth of resistant mutants as well as a phenomenon of phenotypic resistance have been presented.
