In-vitro comparison of macrolides, lincosamides and synergistins on Neisseria gonorrhoeae.

The MIC of erythromycin, oleandomycin, spiramycin, josamycin, lincomycin and pristinamycin was determined for 100 strains of Neisseria gonorrhoeae isolated from cases of acute urethritis in men. The method of dilution in agar was used: blood agar with the addition of 'Polyvitex' and an innoculum of 10(3)-10(4) bacteria per spot. With respect to the break points defined by the C.F.A. all the strains of N. gonorrhoeae studied are sensitive to erythromycin, spiramycin, josamycin and pristinamycin, 12% strains are resistant to oleandomycin and 75% to lincomycin. The active antibiotics are classified as follows according to the active weight expressed by the MIC50: erythromycin, pristinamycin, 0.125 mg/l; josamycin, 0.5 mg/l; spiramycin, oleandomycin, 2 mg/l.