影响肺炎克雷伯菌粘附上皮细胞作用的研究

目的:研究不同理化及生物因素对肺炎克雷伯菌粘附宿主细胞的影响,探讨其粘附宿主细胞的可能机制。方法:用肺炎克雷伯菌临床分离株K.pnueumoniae 03183(K.p03183)建立粘附宿主细胞模型,通过结晶紫染色及扫描电镜观察其粘附效率;以不同理化及生物因素预处理K.p03183,平板菌落计数法观察上述因素对K.p03183粘附细胞的影响;用基因芯片技术,检测HMGN2蛋白预处理细菌对于其粘附相关基因表达的影响。结果:K.p03183可粘附至A549、T24、HeLa等3种上皮细胞系,其粘附率与E.coli 25992接近;氯化锂和盐酸胍、高碘酸钠及热预处理可明显降低K.p03183对于A549和T24的粘附率(P0.05);同时,胃蛋白酶及HMGN2蛋白预处理K.p03183,也可抑制其对A549和T24的粘附(P0.01);但胰蛋白酶预处理却能增加细菌对于A549细胞的粘附(P0.05);同时,HMGN2还可通过上调dksA基因表达,从而干扰细菌粘附细胞。结论:肺炎克雷伯菌可能借助细胞壁及其表面蛋白和碳水化合物等成分粘附至宿主上皮细胞,通过非共价键结合表面蛋白或消除碳水化合物成分,抑制细菌粘附至宿主细胞。

Study on the adhesion of Klebsiella pneumoniae in epithelial cells

Objective： To investigate the dfects and possible mechanism of various physical, chemical and biological factors on the adhesion of Klebsiella pneumoniae 03183 in epithelial cells. Methods： Adhesion efficiency of Klebsiella pneumoniae was evaluated by crystal violet staining and scanning electron microscopy. The effects of various factors on the adhesion of KlebsieIZa pneurnoniae in epithelial cells were determined by plate culture count. Gene chip was used to investigate the adhesion-related gene expression. Results： K. p 03183 could adhere to the A549, T24, and HeLa cells. Lithium chloride, guanidine hydrochloride, sodium periodate and heat, as well as pepsin and HMGN2 pretreatment obviously decreased A549 and T24 cells attachment byK. p 03183 （P〈0.05）. However, trypsin pretreatment increased the adhesion ofK. p 03183 in A549 cells （P〈：0. 05）. Meanwhile, HMGN2 upregulated the dksA expression. Conclusion. K. p 03183 attached to host cell by means of the interactions of bacterial cell wall components （such as surface proteins and carbohydrates） and host cell membrane receptors, which might be inhibited by non-covalently binding the surface protein or eliminating carbohydrate compositions.