Streptomycin Activity and Bioassay

Waksman and Reilly have summarized the factors which have a bearing upon the choice of the method to be employed in measuring quantitatively the activity or potency of an antibiotic substance. They have cited literature references to the more commonly used methods. Loo and coworkers have described a suitable method for the quantitative determination of streptomycin by the filter paper disc, agar plate diffusion technique using Bacillus subtilis as the test organism. The procedure proved satisfactory in the assay of surface and submerged culture beers and of preparations obtained in isolation and purification 

There exists a rather extensive literature concerned mth those specialized bioassay methods developed for the detection and measurement of streptomycin as required in the study of its clinical applications. 

Eisman and coworkers - have investigated the use of microorganisms made resistant to an antibiotic of known chemical and biological properties in order to differentiate it from an unknown antibiotic of similar bacterial spectral analysis. Strains of bacteria which have developed a high resistance to streptomycin have been used to differentiate unknown antibiotics from streptomycin. Some resistant variants have been developed which actually appear to require streptomycin for growth.  

The antibacterial activity of 50 units of streptomycin per milliliter toward S. aureus was suppressed by 0.0002 milligram of lipositol per milliliter. The observers of this interesting phenomenon pointed out that the presence in lipositol of an inositol-galactose structure suggested the possibility of a metabolite-antimetabolite relationship with streptomycin. 

There is presently underway a very considerable amount of bacteriological work having as its objective the elucidation of the mode of action of streptomycin. 

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