In vitro susceptibilities of Chlamydia pneumoniae (Chlamydia sp. strain TWAR).

The in vitro susceptibilities of two clinical isolates of Chlamydia pneumoniae from Brooklyn, N.Y., were determined for tetracycline, erythromycin, sulfamethoxazole, ciprofloxacin, and three new macrolides--azithromycin, clarithromycin, and roxithromycin. Clarithromycin was the most active drug tested, followed by the other macrolides, tetracycline, and ciprofloxacin.