The Action of Sulfonamides and of Para-Aminobenzoic Acid onBacterium tularense

Abstract

Sulfapyrazine in molar conc. of 2 X 10-4 (5 mg%) induced complete bac-teriostasis of Bact. tularense with moderate and large inocula in a very favorable liquid medium. Sulfadiazine and sulfathiazole, in this order, were decreasingly effective inhibitory agents, requiring higher concs. and smaller inocula to produce complete bacteriostasis. p-Aminobenzoic acid did not inhibit sulfonamide bacteriostasis of B. t. In concs. in excess of M X 10-4 PABA alone inhibited growth of this organism. Insofar as in vitro inhibition of virulent organisms is an index of clinical expectation the outlook for therapeutic usefulness of sulfanilamide, neoprontosil, sulfapyridine, sulfaguanidine, sulfathiazole, and sulfadiazine in tularemia is not good. Of the drugs studied, only sulfapyrazine seems worthy of clinical trial.