In Vitro Activity of a New 8-Methoxyquinolone, BAY 12-8039, against Chlamydia pneumoniae

The in vitro susceptibilities of 10 strains of Chlamydia pneumoniae to a new 8-methoxyquinolone, BAY 12-8039, and to ofloxacin, doxycycline, and erythromycin were determined. The activity of BAY 12-8039 was similar to that of ofloxacin, with a MIC at which 90% of the isolates had no inclusions and a minimal chlamydicidal concentration at which 90% of the isolates had no inclusions after passage of 1.0 μg/ml, but this activity was less than those of doxycycline and erythromycin.