CROSS-CANADA SURVEY OF SUSCEPTIBILITY OF NEISSERIA-GONORRHOEAE ISOLATES TO 6 ANTI-MICROBIAL AGENTS

Abstract

The minimum inhibitory concentrations (MIC) of penicillin, ampicillin, tetracycline, erythromycin, spectinomycin and sulfadiazine were determined for 732 isolates of N. gonorrhoeae collected in 1973-74. Comparison of the results of this survey with data from other Canadian studies showed that the percentage of isolates resistant to tetracycline had not changed in patients since 1966, but the percentage of erythromycin-resistant isolates decreased. After an initial increase in 1966 the percentage of penicillin-resistant isolates stabilized. Spectinomycin-resistant isolates were not found. Positive correlations were observed between the MIC of the antibiotics tested; the highest positive correlations were between penicillin and ampicillin and between penicillin and tetracycline. A positive correlation was noted between penicillin resistance and increasing spectinomycin MIC. A significant seasonal variation in MIC was found, the trend being towards increasing MIC during the summer.