奇异变形杆菌潜生体与繁殖体的耐药性差异及其机制探讨

Difference of drug resistance between cryptic growth cells and vegetative cells of P. mirabilis and its mechanism

目的：观察奇异变形杆菌潜生体与繁殖体的耐药性差异并探讨其发生机制。方法：采用一株自己构建的标准产酶菌株和一株临床分离菌株，经波动培养法诱导产生潜生体及繁殖体，检测二者的耐药性差异，并通过β－内酰胺酶活性分析、外膜通透率测定及外膜蛋白ＳＤＳ－ＰＡＧＥ检测来探讨其发生机制。结果：潜生体的耐药程度普遍高于繁殖体，二者的β－内酰胺酶活性差异不显著（Ｐ＞０．０５），潜生体外膜通透率降低且有多种外膜蛋白减少或缺失。

Objective: To investigate the difference of drug resistance between cryptic growth cells (CGCs) and vegetative cells (VCs) of P. mirabilis and explore its mechanism. Methods: A standard strain of P. mirabilis producing β lactamase and a clinical isolate of P. mirabilis were used to induce CGCs and VCs under wave culture condition, the minimum inhibitory concentration (MIC) of CGCs and VCs was measured to observe their difference of drug resistance. The mechanism of the difference was explored through analysis β lactamase activity, test of outer membrane (OM) permeability and SDS PAGE of OM protein. Results: The level of drug resistance was higher in CGCs than in VCs but no significant difference in β lactamase activity was found between the two ( P >0.05). OM permeability and the contents of many kinds of OM protein were significantly decreased. Conclusion: The decrease of a wide range of OM protein may play an important role in the increase of drug resistance of CGCs.