Resistance of Neisseria gonorrhoeae to antibacterial drugs in Ontario.

Observations on multiple resistance of 227 N. gonorrhoeae strains are presented in this paper. These strains were previously isolated from the urogenital area from patients who did not respond to antibacterial drug treatment. The above-mentioned strains were referred to our laboratory for confirmation and for susceptibility testing. All the N. gonorrhoeae strains showed resistance in vitro to penicillin concentrations between 0.5-2.0 i.u./mi. In addittion to penicillin resistance, 83.7% showed resistance to cephaloridine, 72.2% to kanamycin, 58.1% to spiramycin, 51.5% to erythromycin, 41.4% to sulphadiazine, 37.0% to tetracycline, 29.9% to ampicillin and 25.1% to spectinomycin.