Antibacterial Action of Several Sulfonamide Compounds on Hemophilus influenzae Type B

Abstract

Six drugs and 6 cultures of equal virulence were used. For in vivo comparison, mice were given orally one dose of a drug, followed by intraperit. inoculation of culture suspended in mucin. Sulfadiazine was the most effective, followed by sulfathiazole and para-nitrobenzoic acid of similar activity, sulfapyridine, sulfanilyl sulfanilamide and sulfanilamide. The last was active against only 1 culture. In vitro the cultures were grown in the presence of 10 mg.% in MacLeod''s liver-infusion medium. Sulfadiazine, sulfathiazole, sulfapyridine and sulfanilyl sulfanilamide either markedly retarded growth or killed the bacteria. Action of first 2 was similar and slightly better than latter 2. Sulfanilamide showed very little activity except against one culture. Both in vivo and in vitro variation in susceptibility of the cultures was evident. More than 6 times as much sulfapyridine was required to protect mice against the most resistant culture as compared with the least resistant one. Results of treatment of mice with a combination of sulfadiazine or sulfapyridine with specific antiserum seemed to be better than an additive effect of the 2 agents. Cultures varied in susceptibility to antiserum but sensitivity was not correlated with drug sensitivity.