Antimicrobial sensitivity of Neisseria gonorrhoeae. Comparison of penicillinase producing and non-penicillinase producing strains.

The sensitivity of 42 strains of penicillinase producing Neisseria gonorrhoeae (PPNG) and 46 strains of non-PPNG was tested against benzyl penicillin, spectinomycin, erythromycin, cefuroxime, ceftriaxone, tetracycline, sulphamethoxazole, and trimethoprim. The minimum inhibitory concentrations (MICs) of all antimicrobials, except trimethoprim and ceftriaxone, differed significantly for PPNG and non-PPNG strains. Ceftriaxone was the most active compound tested, the MIC for all strains being less than or equal to 0.015 mg/1. PPNG were less sensitive than non-PPNG strains to spectinomycin. It remains to be seen whether the increase in prevalence of PPNG strains is followed by a gradual increase in low level resistance to spectinomycin as well as the occasional finding of high level resistance to this antibiotic.