A Mechanism for the Development of Resistance to Streptomycin and Penicillin

Abstract

The development of resistance to streptomycin was studied using the 2 organisms Escherichia coli and Proteus vulgaris, and several strains each of Staphylococcus aureus, S. albus, and Streptococcus viridans. Very large amts. of the organisms were used to obtain a single resistant variant. Variants resistant to high concs. of streptomycin numbered 57 while no variants resistant to a high conc. of penicillin were found. Increase in resistance developed much more rapidly toward streptomycin than toward penicillin.