Studies on the Action of Sulfonamides on the Respiration and Growth of Bacteria

Abstract

Para-, meta-, ortho-aminobenzenesulfonamides, and para-aminobenzoic acid inhibited the respiration and growth of pneumococcus Type I, when measured in glucose and yeast extract medium. The inhibitions were either markedly reduced, or abolished, when the system contained serum proteins. These substances did not inhibit either respiration or growth of staphylococcal strains in media containing a) buffer mixture and glucose; b) glucose and yeast extract; and c) glucose and serum with or without yeast extract. Sulfanilamide and sulfathia-zole inhibited the growth of staphylococcal strains in vitamin-free casein hydrolyzate. These inhibitions were either abolished or markedly reduced when serum was also included in the medium. These observations are in agreement with clinical results with respect to the inefficacy of the above-mentioned drugs. They indicate that serum proteins.compete with bacterial enzymes for these drugs. In this respect, results of studies on the inhibition of respiratory enzymes and growth by sulfonamides appear to be in agreement.