fima介导f18ab+大肠杆菌病原性的研究

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1、FimA介导F18ab+大肠杆菌病原性的研究StudyonFimAmediatedF18ab+Escherichicolipathogenicity——一研究生：郭志燕导师：朱国强教授扬州大学畜禽病原微生物研究室2014年6月郭志燕：FimA介导F18ab+大肠杆菌病原性的研究!FimA介导F18鉴暨杆菌病原性的研究㈣Y263㈣2657帆中文摘要II一扬少i'l大学硕士学位论文其相邻的上下游基因timE和tim!的转录，排除了由此调控带来影响。Real．timePCR试验检测I型菌毛对于F18ab大肠杆菌其它表面黏附素的调控作用结果，与野生株相比，f

2、liC(编码鞭毛丝蛋白主要结构亚基)、leaF(编码F18菌毛主要结构亚基)分别下调至73％和71％，差异不显著，AIDA．，则上调至野生株的3．3倍(0．01

3、和空肠，从而初步在动物体内验证了I型菌毛在肠道上皮的定植作用。综上所述，I型菌毛对于F18ab+STEC的病原性是十分重要的。关键词：F18ab+大肠杆菌，I型菌毛，fimA基因，黏附，侵袭，生物被膜，小鼠模型郭志燕：FimA介导F18ab+大肠杆菌病原性的研究StudyonFimAmediatedF18ab+EscherichicolipathogenicityAbstractEdemadisease(ED)andpost-weaningpostweaningdiarrhea(PWD)arebothfrequentlyfataldiseasetha

4、tusuallyOccursinpost-weaningpiglets．AffectedpigsdiequicklyoncetheydevelopingsymptomsandsurvivingpigsmaygrowslowlyThereisnoeffectivevaccineorreliabletherapyofthisdiseasewhichhascausedgreateconomiclossinthewholeworld．F18ab+STEC(ShigaToxinproducingEscherichiacoli)istheprincipalpat

5、hogenicbacterialeadingtodiarrhoea，edema，andmortality．Asweallknown，adhesionsincludingF18abfimbriae，typeIfimbriae，flagella，AIDA(adhesininvolvedindiffuseadherence)andtoxinsaretwomajorpathogenicfactorsofF18ab+STECcausinginfection，althoughthemechanismisremainstobeelucidated．Giventhe

6、provenroleoftypeIfimbriaeinurinarytractinfections(UTIs)，itisreasonablehypothesisethatitplaysadirectroleinentericpathogenesis，whichisnottobefullydefined．ThisstudytargetatthemajorstructuresubunitFimAoftypeIfimbriae，exploringtheroleoftypeIfimbriaeinpathogenicityofF18ab+STEC．Basedo

7、ntheoriginalsequencesoffimAgenewithdifferentresourcesinGenebank，weusedprimerstodetectandamplifythemajorstructuresubunitoftypeIfimbriaeinF18ab(Wild-type，0139：H1：F18ab，Stx2e)．ThepurifiedPCRproductwasclonedintoTvectorandconfirmedbyDNAsequencing．Thenwedesignprimerswhichcontainahomo

8、logies5’terminaltothetargetregionandahomologies3’termi