IN-VITRO ACTIVITIES OF AZITHROMYCIN, CLARITHROMYCIN, ERYTHROMYCIN, AND TETRACYCLINE AGAINST 13 STRAINS OF CHLAMYDIA-PNEUMONIAE

Thirteen strains of Chlamydia pneumoniae were evaluated for their in v itro susceptibilities to azithromycin, clarithromycin, erythromycin, a nd tetracycline. The MIC ranges were 0.125 to 0.5 mu g/ml for azithrom ycin, 0.031 to 1.0 mu g/ml for clarithromycin, 0.125 to 1.0 mu g/ml fo r erythromycin, and 0.125 to 1.0 mu g/ml for tetracycline, The ranges for the minimal lethal concentrations were 0.125 to 0.5 mu g/ml for az ithromycin. 0.031 to 1.0 mu g/ml for clarithromycin, 0.125 to 1.0 mu g /ml for erythromycin, and 0.25 to 1.0 mu g/ml for tetracycline. Clarit hromycin and azithromycin were the most active antibiotics against C. pneumoniae in vitro.