Effects of Penicillin, Streptomycin, and Tetracycline on N. gonorrhoeae isolated in 1944 and in 1957

Abstract

The 50% inhibitory concentration of penicillin for strains isolated in 1944 showed a normal distribution around 0.01 [mu]g/ml with a 6-fold range. The 1957 strains showed a 2 peak distribution, one peak at about 0.01 [mu]g, the other about 0.2 [mu]g. The range of gonococcus strains in 1957 submitted solely for diagnosis was 80-fold, but the range in strains submitted for antibiotic sensitivity studies, (strains from problem cases) was 180-fold and a higher percentage of these strains required about 0.2 [mu]g. There was little difference in sensitivity to streptomycin and tetracycline between the 1944 and 1957 strains.