五种常用抗菌药物对泌尿生殖道沙眼衣原体的单独和联合药敏作用

In vitro susceptibilities of urogenital Chlamydia trachomatis to five antimicrobial agents alone or in combination

目的 探讨泌尿生殖道沙眼衣原体D-UW-5/Cx型、E-UW-5/Cx型、G-UW-5/Cx型标准株对阿奇霉素、米诺环素、莫西沙星、多西环素和利福平5种常用抗菌药物体外单独和联合药物敏感性.方法 将沙眼衣原体D、E、G型菌株振荡、离心后接种于细胞培养板的McCoy细胞,使McCoy细胞感染率达90%以上后进行药敏试验.采用微量稀释法测定5种抗菌药物体外对沙眼衣原体的单独作用,进而通过棋盘稀释法测定6组抗菌药物联合后的体外相互作用情况.结果 在体外,阿奇霉素、莫西沙星、多西环素,米诺环素、利福平的最低抑菌浓度分别为0.25、0.06、0.063～0.25、0.032～0.064、0.008 mg/L.阿奇霉素与莫西沙星、多西环素或利福平联合时,其部分抑菌浓度指数均为0.75,对沙眼衣原体有相加作用.而米诺环素与阿奇霉素、莫西沙星或利福平联合时,其部分抑菌浓度指数分别为2.5、2.83、4,相互之间有拮抗作用.结论 在体外,阿奇霉素与莫西沙星、多西环素或利福平联用,抗菌活性显著提高.而米诺环素与莫西沙星、多西环素或利福平联合应用时,它们之间的拮抗作用将降低各自的抗菌活性.

Objective To test the in vitro acitivity of azithromycin, minocyline, moxifloxacin, doxycycline and rifampicin alone or in combination against three standard strains of urogenital Chlamydia trachomatis,i.e. D-UW-5/Cx, E-UW-5/Cx and G-UW-5/Cx. Methods Three standard strains of C. trachomatis were inoculated into McCoy cells, and used to susceptibility testing after more than 90% McCoy cells were infected.Microdilution method was applied to determine the activity of the 5 antimicrobial agents alone, and checkerboard array to determine that in combination. Results The in vitro minimal inhibitory concentrations （MICs）were 0.25 mg/L for azithromycin, 0.06 mg/L for moxifloxacin, 0.063 - 0.25 mg/L for doxycycline, 0.032 -0.064 mg/L for minocyline, 0.008 mg/L for rifampicin. And, the fractional inhibitory concentration index was constantly 0.75 for the combination of azithromycin with moxifloxacin, doxycycline and rifampicin, 2.5, 2.83and 4 for the combination of minocyline with azithromycin, moxilloxacin and rifampicin, respectively. Conclusions As far as the activity against C. trachomatis is concerned, there is a synergism for the combination of azithromycin with moxifloxacin, doxycycline and rifampicin, but antagonism for the combination of minocyline with azithromycin, moxifloxacin and rifampicin.