Antimycobacterial activity of isoniazid + prothionamide + dapsone against a number of randomly selected 'wild' strains of Mycobacterium tuberculosis.
46 strains of Mycobacterium tuberculosis were studied as to their susceptibility to isoniazid (INH) or to INH + prothionamide (PTH) in the presence or absence of dapsone (DDS) by microdilution transfer plate technique. Synergy with DDS as defined by Berenbaum in 1978 was seen in 78% with INH and in 91% with INH + PTH. It concerned the minimal inhibitory concentration, whereas the minimal bactericidal concentration (MBC) was unaffected in the case of INH and it was increased in only 52% with INH + PTH. The latter MBC proportion mentioned would be decreased to roughly 16% accepting an only twofold decrease in the MBC as possibly due to dilution errors. The possible effect of dimethyl sulphoxide on the reported results is discussed.
D003622:Dapsone / Q000494:pharmacology*; D004357:Drug Synergism; D007538:Isoniazid / Q000494:pharmacology*; D007539:Isonicotinic Acids / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D011515:Prothionamide / Q000494:pharmacology*
D007539:Isonicotinic Acids; D011515:Prothionamide; D003622:Dapsone; D007538:Isoniazid