In Vitro Activities of Seven Quinolone Antibiotics against Genital Chlamydia Trachomatis

Objective:To detect and compare activities of seven quinolone antibiotics against recent clinical isolated genital chlamydia trachomatis(CT) in vitro. Methods:The MIC of 7 quinolone antibiotics were evaluated using 18 strains of clinical isolated CT.The MIC of each agent was defined as the lowest concentration of drug at which no typical inclusions were identified after the first passage in McCoy cell culture.Furthermore,MBC was defined by permitted no inclusions to be formed upon second passage in antimicrobial drug-free medium. Results:The MIC90 and MBC90 of the quinolone antibiotics respectively is,Ciprofloxacin MIC90=2.0 mg/l,MBC90=4.0 mg/l,Ofloxacin MIC90=1.0 mg/l,MBC90=2.0 mg/l;Levofloxacin MIC90=1.0 mg/l,MBC90=2.0 mg/l;Fleroxacin MIC90=2.0 mg/l,MBC90=4.0 mg/l;Sparfloxacin MIC90=0.063 mg/l,MBC90=0.125 mg/l;Toufloxacin MIC90=0.125 mg/l,MBC90=0.25 mg/l and Moxifloxacin MIC90=0.031 mg/l,MBC90=0.0 63 mg/l. Conclusion:Ciprofloxacin,Ofloxacin,Levofloxacin and Fleroxacin have high lever of MIC90 and MBC90,they exibit insufficient in vitro anti-CT activity,but Sparfloxacin,Toufloxacin and Moxifloxacin show better activities against recent clinical isolateed genital CT in vitro.