RT Journal Article SR Electronic T1 IN VITRO STUDIES OF SULFONAMIDE ACTION ON ORGANISMS OF THE BRUCELLA GROUP AND THE COUNTERACTING EFFECT OF PARA-AMINOBENZOIC ACID JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 156 OP 160 VO 76 IS 2 A1 WISE, BOWMAN YR 1942 UL http://jpet.aspetjournals.org/content/76/2/156.abstract AB Comparison of the bacteriostatic action of sulfathiazole, sulfadiazine, and sulfaguanidine on 7 brucella strains has shown sulfathiazole and sulfadiazine to have almost the same effect. The bacteriostatic effect of sulfaguanidine is more variable, and frequently much less marked than that of the other drugs. Sulfathiazole and sulfadiazine, in increasing concentrations above 2.5 mg.%, exhibit very small or no differences in bacteriostatic action, whereas the bacteriostatic effect of sulfaguanidine frequently varies directly with the drug concentration. P-aminobenzoic acid in concentrations of 0.1 and 1.0 mg.%, partially or almost completely inhibits the action of sulfathiazole. Organisms exposed to the action of sulfathiazole for 48 hours, then explanted to drug-free broth, show a continued inhibition of growth, which is not due to "carry over" of sulfathiazole in the explants. This persisting inhibitory effect is counteracted by p-aminobenzoic acid.