Activity in vitro of ten antimicrobial agents against Neisseria gonorrhoeae. A study of the correlation between the sensitivities

Abstract

105 Belgian strains of Neisseria gonorrhoeae were tested for their sensitivity to penicillin, ampicillin, rifampicin, erythromycin, tetracycline, streptomycin, spectinomycin, sulphamethoxazole, trimethroprim, and a combination of sulphamethoxazole and trimethroprim in a 5:1 ratio. Distribution and median values of minimum inhibitory concentrations (MICs) are given and discussed. 42% of the strains were relatively resistant to penicillin (MIC ≥ 0.04 μg/ml.), but only 2% showed high level resistance (MIC ≥ 0.38 μg/ml.), which is comparable with the prevalence of decreased sensitivity found in other European countries. A significant positive correlation (P ≤ 0.01, rank correlation coefficient) is found between the sensitivities to penicillin, ampicillin, erythromycin, tetracycline, and streptomycin, except for the ampicillin erythromycin and ampicillin tetracycline pairs. Rifampicin is correlated with tetracycline. No correlation is found between the sensitivities to spectinomycin and any of the other drugs. The combination of sulphamethoxazole and trimethoprim in a 5:1 ratio also shows a significant positive correlation with penicillin and ampicillin and with sulphamethoxazole and trimethoprim separately.