In vitro susceptibility of Neisseria gonorrhoeae to cefuroxime, penicillin, and tetracycline in Denmark-1979

In vitro susceptibility to cefuroxime, penicillin, and tetracycline of 963 strains of Neisseria gonorrhoeae strains isolated in Denmark in 1979 was tested. If penicillinase-producing strains of N. gonorrhoeae were excluded from the analysis, a significant positive correlation between the 50% inhibitory concentrations (IC50) of cefuroxime and penicillin was observed (r = 0.87). Among strains exhibiting IC50 of penicillin of greater than or equal to 0.30 microgram/ml, 80% (106/133) had an IC50 of cefuroxime of greater than or equal to 0.088. Ninety-six per cent (106/110) of strains exhibiting an IC50 of cefuroxime of greater than or equal to 0.088 microgram/ml were less susceptible to penicillin (IC50, greater than or equal to 0.30 microgram/ml). The IC50 values of tetracycline were positively correlated with those of cefuroxime. There was no apparent difference between the level of antimicrobial susceptibility of strains (623) isolated from urogenital sites and that of strains (109) from the pharynx.