Zheng Heping, Xue Yaohua, Bai Shun, Qin Xiaolin, Lu Ping, Yang Bin
From the *Guangdong Provincial Dermatology Hospital/Guangdong Provincial Center for Skin Diseases and STD Control, Guangzhou, China; and †Xiangya School of Medicine, Central South University, Changsha, China.
Sex Transm Dis. 2015 Mar;42(3):115-9. doi: 10.1097/OLQ.0000000000000241.
The presence of persistent Chlamydia trachomatis infection after treatment does not always correlate with in vitro susceptibility testing.
The in vitro minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of azithromycin, clarithromycin, roxithromycin, doxycycline, tetracycline, ofloxacin, and penicillin were tested against 61 clinical isolates of C. trachomatis on 6 serovars, and the MIC/MBC of azithromycin and ofloxacin at different points in time after antibiotic administration to infected cultures.
Of the 7 antibiotics tested, clarithromycin showed the greatest activity against C. trachomatis isolates with MIC90 of 0.032 μg/mL and MBC90 of 0.064 μg/mL, followed by doxycycline with MIC90 0.064 μg/mL and MBC90 0.064 μg/mL, and azithromycin with MIC90 0.160 μg/mL and MBC90 0.320 μg/mL. Azithromycin had roughly the same MIC50 values (0.08 μg/mL) as the other serovars isolates tested, and other antibiotics showed a 2- to 4-fold difference in MICs50 between serovars. In addition, an increase in the azithromyin MIC was observed by 8 hours and the ofloxacin MIC by 16 hours. At 24 hours, the azithromycin MICs were greater than 40 μg/mL and ofloxacin MICs were greater than 64 μg/mL.
The current data demonstrated that the antimicrobial susceptibility of C. trachomatis was influenced by both the serovar type and the duration of exposure to antibiotics in infected cultures.
治疗后沙眼衣原体持续感染的存在并不总是与体外药敏试验结果相关。
对6种血清型的61株沙眼衣原体临床分离株进行阿奇霉素、克拉霉素、罗红霉素、多西环素、四环素、氧氟沙星和青霉素的体外最低抑菌浓度（MIC）和最低杀菌浓度（MBC）检测，并检测感染培养物在给予抗生素后不同时间点阿奇霉素和氧氟沙星的MIC/MBC。
在测试的7种抗生素中，克拉霉素对沙眼衣原体分离株的活性最强，MIC90为0.032μg/mL，MBC90为0.064μg/mL；其次是多西环素，MIC90为0.064μg/mL，MBC90为0.064μg/mL；阿奇霉素的MIC90为0.160μg/mL，MBC90为0.320μg/mL。阿奇霉素的MIC50值（0.08μg/mL）与其他测试血清型分离株大致相同，其他抗生素在不同血清型之间的MIC50差异为2至4倍。此外，观察到阿奇霉素的MIC在8小时时升高，氧氟沙星的MIC在16小时时升高。在24小时时，阿奇霉素的MIC大于40μg/mL，氧氟沙星的MIC大于64μg/mL。
目前的数据表明，沙眼衣原体的抗菌药敏性受血清型类型和感染培养物中抗生素暴露持续时间的影响。
