肺炎克雷伯菌KbvR调控I型菌毛FimH的合成与功能研究  

The role and function of KbvR regulation on the FimH of type I fimbriae

作　　者：张福升 徐丽 黄奕诚 雷飞飞[3] 李蓓 ZHANG Fu-sheng;XU Li;HUANG Yi-cheng;LEI Fei-fei;LI Bei(School of Basic Medical Science,Hubei University of Medicine,Shiyan,Hubei 442000,China;Second Clinical School,Hubei University of Medicine;Renmin Hospital,Hubei Universityof Medicine)

机构地区：[1]湖北医药学院基础医学院,湖北十堰442000 [2]湖北医药学院第二临床学院 [3]湖北医药学院附属人民医院

出　　处：《中国病原生物学杂志》2022年第7期766-769,共4页Journal of Pathogen Biology

基　　金：湖北省卫生健康委面上项目(No.WJ2021M056);湖北省教育厅青年人才项目(No.Q20142106)。

摘　　要：目的明确KbvR对I型菌毛顶端蛋白编码基因fimH的调控作用及其生物学功能。方法在kbvR基因敲除株的基础上构建kbvR与fimH基因的双敲除株,通过扫描电镜、RT-PCR、酵母凝集试验、细胞试验等方法分析在kbvR基因敲除及ΔkbvRΔfimH基因双敲除时细菌I型菌毛的形成、生物膜产生、对吞噬细胞的侵袭能力改变。结果RNA-seq及RT-PCR半定量试验显示kbvR基因敲除株中fimH基因表达增加,扫描电镜及酵母凝集试验显示kbvR基因敲除株菌毛形成能力增强。通过同源重组的方式在kbvR基因敲除株的基础上成功获得ΔkbvRΔfimH双基因敲除株。相对于kbvR基因敲除株,ΔkbvRΔfimH双基因敲除株菌毛形成降低,对抗巨噬细胞吞噬能力提升,但生物膜形成能力无明显变化。结论KbvR对肺炎克雷伯菌I型菌毛FimH蛋白合成起负调控作用,并通过对I型菌毛的合成而影响细菌的抗吞噬能力,但不参与细菌生物膜形成。Objective To clarify the regulatory effect of KbvR on the type I fimbriae encoding gene fimH and the biological function of regulation.Methods The double genes knockout strain of kbvR and fimH(ΔkbvRΔfimH)were constructed on the basis of kbvR gene knockout strain(ΔkbvR).Then the production of type I fimbriae,biofilm formation and anti-phagocytosis ability of WT,ΔkbvR andΔkbvRΔfimH strains were detected by scanning electron microscope,RT-PCR,yeast agglutination test and phagocytosis assay.Results RNA-seq and RT-PCR showed the expression of fimH gene increased in kbvR gene knockout strains.Scanning electron microscopy and yeast agglutination test also demonstrated that the fimbriae formation ability of kbvR gene knockout strain was significantly increased.TheΔkbvRΔfimH double genes knockout strain was successfully constructed by homologous recombination.Compared toΔkbvR strain,the fimbriae ofΔkbvRΔfimH strain was decreased and the uptake by the macrophages was significantly lower than theΔkbvR strain.Although the biofilm formation ofΔkbvR andΔkbvRΔfimH were decreased than WT strain,there was no significant difference between them.Conclusion In Klebsiella pneumoniae,KbvR regulator can negatively regulate the synthesis of FimH protein of type I fimbriae,and this regulation take part in the anti-phagocytosis but not the biofilm formation.

关 键 词：肺炎克雷伯菌 KbvR调控子 菌毛 fimH基因 

分 类 号：R378.9[医药卫生—病原生物学]