The Bactericidal Effect of Sulfanilamide upon Beta Hemolytic Streptococci in Vitro

Abstract

Bactericidal action (sterilization), with 20 mg.% of sulfanilamide, in PD broth and in defibrinated horse blood, was obtained, after 48 hours'' incubation at 39-40[degree] C, with 36 strains of [beta] hemolytic streptococci recently isolated from human infections. Inhibition, but not sterilization, was obtained with similar mixtures incubated at 36-38[degree] C. An average initial conc. of 5000 bacterial units, per cc. of test mixture was used. Growth curves, to show the beginning and progress of the bactericidal action to the point of sterility, were obtained with 4 strains. Delay of the drug''s action for at least 3 hours was typical. The possible clinical significance of bactericidal action with sulfanilamide at 39-40[degree] C is discussed.