小鼠感染猪致病性大肠杆菌模型的构建与病理研究

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Abstract：PorcinepathogenicEscherichiacoli，isanimportantpathogenthatcausesintestinaldisease，septicaemiaand urinary tract infections.Inordertoexploretheinjury mechanisminducedbypathogenic Escherichia coli，this experiment randomly divides 50 8-to 9-week-old Babl/c female mice into 10 groups，with 5 mice in each group.Four model groups areintraperitoneallyinjected with 300μL E.coli at concentrations of 1×106 cfu/mL， 1×107 cfu/mL， 1×108cfu/mL 1×109 （204号 cfu/mLrespectively，while thecontrol groupmiceare intraperitoneallinjected withanequal volumeofsterilizedPBS. After72hoursofobservation，thehistopathological changesareobservedand thecelular inflammatory factors interleukin-2（IL-2）and interleukin-6（IL-6）aredetected.Theprokaryoticexpressionvectorexpressinggreenfluorescent protein（GFP） is transformed into pathogenic E coliEC2316 by electroporation transformation method，and the strain EC2316-GFPexpressng green fluorescence is obtained.The results show that the median lethal doseof strain EC2316 is 2×107 cfu/mL.The bacterial colonization in organs increases with rising bacterial concentration，and IL2 and IL-6 increased significantly.The introductionof GFPdid not alters the growth characteristicsof strain EC2316.In summary， the pathological changes and inflammatory responses observed in mice infected with porcine pathogenic E⋅ coliclosely resemble those documented in naturally occurring cases.A mouse model of porcine pathogenic E .coli infection is successfullyestablished，whichprovidestheoreticalandpractical foundation forfurtherresearch intothedamage mechanisms caused byE.coli.

Keywords：Porcine pathogenic Escherichia coli; GFP;LD50;mouse model

猪致病性大肠杆菌病（PorcinepathogenicEscherichiacoli），是危害猪养殖业的一大挑战，研究显示，该疾病在引发猪只死亡原因中占有显著比例，尤其是对仔猪群体构成了严重威胁[1，2]。（剩余9640字）