Abstract
A comparative study was carried out on the determination of streptomycin-resistance of tubercle bacilli in sputum by the popularly employed direct method using solid media, by my quantitative manifestation method for resistance, and by the ordinary indirect quantitative method which is periormed after isolating tubercle bacilli from sputum. Following conclusions have been drawn.
1) The direct method by solid medium, that is the direct inoculation of concentrates of sputum on to a modified Urabe-Yamada's egg yolk agar containing 0.10 and 100μ of streptomycin per cc, of medium is a method easily performed clinically.
2) When an equal quantity of concentrates of sputum is inoculated on each medium, the ratio between streptomycin-resistant tubercle bacilli and the entire organisms in sputum may be shown by the direct method from the growth of colonies on the media containing streptomycin of various concentrations. However, to secure a more exact ratio, a quantitative
manifestation method must be used.
3) But we should not take the highest streptomycin concentration in which growth may be noted, as the index of resistance of tubercle bacilli in sputum. The reason for this is that the greater the quantity of concentrates of sputum is inoculated on each medium, the larger number of high resistant bacilli may be found to grow on streptomycin containing
medium of high concentration, or vice versa.
