氟喹诺酮体外诱导肺炎克雷伯菌外排蛋白表达差异的研究

A Study on the Difference of Efflux Protein Expression between Klebsiella Pneumoniae Used in Vitro Fluoroquinolone and Ones Not Used

目的探讨氟喹诺酮体外诱导肺炎克雷伯菌外排蛋白表达的差异。方法取临床分离对喹诺酮敏感的肺炎克雷伯菌20株,分2组,每组10株,1组作对照组,观察组将应用不同浓度梯度环丙沙星逐级诱导,最后成为耐药株,观察2组细菌在不同浓度抗生素应用后的差异,并比较观察组的10株敏感菌和诱导后耐药菌在应用外排泵抑制剂前后最低抑菌浓度(MIC)及SDS-PAGE电泳外排泵膜蛋白表达的差异。结果环丙沙星从小至大剂量体外诱导出高度耐药株的出现,其53KDa外膜蛋白TolC表达增多。应用外排泵抑制剂利血平后,70%诱导耐药菌MIC有明显下降。结论喹诺酮体外诱导可使肺炎克雷伯菌的耐药性出现,TolC表达增多表明外排泵在肺炎克雷伯菌耐药机制中起重要作用。外排泵抑制剂的应用对肺炎克雷伯菌耐药有一定的遏制作用。

Objective To study the difference of efflux protein expression between klebsiella pneumoniae used in vitro fluoroquinolone and ones not used. Methods 20 sensitive klebsiella pneumoniae isolated from patients were divided into 2 groups . One group, 10 bacteria, were acted as contrast group. The other group, induced by different- density ciproxacin, and changed into resistant - ciproxacin klebsiella pneumoniae, were acted as survey group. Then monitor the difference of Minimum Inhibitory Concentration （MIC） according to using the inhibitor of efflux pump and expressing outer- membrane protein TolC between two groups. Results Induced by ciproxacin of from low to high density, sensitive clinical klebsiella pneumoniae were turned to high - resistance bacteria and outer- membrane protein TolC ,53KDa, increased significantly. MIC was decreased by inhibitory of efflux pump in 70% resistant bacteria. Conclusions In vitro fluoroquinolone use can lead to the appearance of resistant klebsiella pneumoniae. The TolC increase indicate that efflux mechanism plays an important role in resistant bacteria. The inhibitor of efflux pump may some repress bacterium resistance.