沙眼衣原体临床株对利福平的体外敏感性及rpoB基因耐药突变检测

In vitro activity of rifampin against and rpoB mutations in Chlamyclia trachomatis clinical isolates

目的检测沙眼衣原体临床株对利福平的体外敏感性，探讨rpoB基因突变与临床耐药的关系。方法采用微量细胞培养法确定利福平对52株沙眼衣原体临床株的最低抑菌浓度。扩增所有临床株以及标准株rpoB基因，然后进行单链构象多态性分析。并随机选取两株临床株进行测序。结果52株临床菌株中未检出耐药株，利福平的最低抑菌浓度是0．004～0．030mg／L。SSCP和测序均未发现rpoB耐药突变。结论利福平治疗沙眼衣原体失败患者未检测到rpoB基因突变，利福平治疗失败与多种因素有关。

Objective To evaluate the susceptibility of Chlamydia traehomatis clinical isolates to rifampin, and assess the relationship between rpoB mutations and antibiotic resistance in them. Methods A microcuhure method was used to determine the minimal inhibitory concentration （MIC） of rifampin in 52 Chlamydia trachomatis clinical isolates. The rpoB gene was amplified from all the clinical isolates and a standard strain of Chlamydia trachomatis followed by single-strand conformation polymorphism （SSCP）analysis. Sequencing of PCR products was carried out for two clinical isolates. Results No rifampin-resistant strain was found among these clinical isolates. The MIC of rifampin varied from 0.004 to 0.030 mg/L. Neither SSCP analysis nor sequencing showed rpoB mutations. Conclusions No rpoB mutations were found in Chlamydia trachomatis isolates from patients unresponsive to rifampin. The unresponsiveness to rifampin may be attributed to multiple factors.