title: Disc-agar diffusion microbiological assay procedure for determining serum and urine levels of sulfacytine and other sulfonamides.
abstract: A reasonably precise, reproducible, and sensitive microbiological procedure for directly assaying sulfacytine and other sulfonamides as antibacterially active drugs has been developed by appropriately modifying the standard disc-agar diffusion technique. Blood and urine levels as low as 3 mug/ml may be determined through the use of a strain of Escherichia coli and a chemically defined agar medium devoid of sulfonamide antagonists. Results indicate that this assay method should be a useful adjunct to the Bratton-Marshall colorimetric procedure, by permitting the direct measurement of antibacterially active drug in clinical specimens.
mesh_terms: D000362:Agar; D001681:Biological Assay; D003124:Colorimetry; D003470:Culture Media; D003596:Cytosine / Q000097:blood / Q000652:urine; D004058:Diffusion; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D008722:Methods; D013411:Sulfadiazine / Q000097:blood / Q000652:urine; D013419:Sulfamethizole / Q000097:blood / Q000652:urine; D013421:Sulfamethoxypyridazine / Q000097:blood / Q000652:urine; D013444:Sulfisoxazole / Q000097:blood / Q000652:urine; D013449:Sulfonamides / Q000097:blood* / Q000652:urine*
chemical_list: D003470:Culture Media; D013449:Sulfonamides; D013411:Sulfadiazine; D013419:Sulfamethizole; D013444:Sulfisoxazole; D003596:Cytosine; D000362:Agar; D013421:Sulfamethoxypyridazine