简介：

简介：Wereportedanovelmammalianreovirus,designedBYD1,isolatedfromthroatswabsofpatientswithsevereacuterespiratorysyndrome(SARS),in2003.Inthepresentstudy,wefirstlycomparedthegenomeelectrophoreticmigrationpatternsofreovirusBYD1with3prototypereovirusstrainsbypolyacrylamidegelelectrophoresis(PAGE)anddeterminedthecompletenucleotidesequenceoftheS1genesegmentofBYD1bysingleprimeramplificationtechnique.TheelectropherogramofBYD1wasdifferentfromthoseofthe3prototypestrainsandanyotherreovirusisolatesreportedbefore.TheentireS1segmentsequenceofBYD1is1437bplongwithtwomeaningfulopenreadingframes(ORFs).ThelongestORFencodesσ1,thecellattachmentprotein,andthesecondlongestORFsupposedlyencodesσ1s,animportantnonstructuralvirulencefactor.TheterminalsequencesofS1segmentare5'GCUAand3'UCAUC,whichareconsistentwiththoseofothermammalianreoviruses.Thehighesthomologyofdeducedσ1aminoacidsequenceis64%identitywithknownmammalianreoviruses.PhylogeneticanalysisofbothS1nucleotidesequenceandσ1aminoacidsequenceindicatedtheBYD1isolatebelongedtoanewcladeofserotype2group.TheresultsofthisstudyshowedthattheBYD1S1segmentwasmarkedlydifferentfromthoseofisolatesreportedbeforeandBYD1wasanovelhumanreovirusisolate.

简介：ThepurposeofthisstudywastoconstructaneukaryoticDNAvectorencodingamultipleepitopeantigen(MFC)ofhepatitisCvirus(HCV)andahepatitisBsurfaceantigen(HBsAg),andexploretheeffectofHBsAggeneontheimmunityofHCVmultiple-epitopeDNAconstructinvitroandinvivoinmice.AnHCVDNAvector(pVAX1-HBs-MFC)wasconstructedbyfusingHBsAggenetotheNterminalofanHCVmultiple-epitopeantigengene.ThepVAX1-HBs-MFCwastransfectedintoHEK293TcellsanditsexpressionwasmeasuredbyELISAandWesternblotting.BALB/cmicewereintramuscularlyimmunizedwiththepVAX1-HBs-MFC,andanELISAapproachwasappliedtodeterminethespecificantibodytitersandsubtypesinthemouseserum.Thecross-reactivityoftheantibodieswasalsocheckedwithtwosynthesizedHCVhypervariableregion1(HVR1)peptides.TheIFN-γproductionandcellproliferationofthemousespleencellswereevaluatedbyELISAandMTS(3-[4,5-dimethylthiazol-2-yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2H-tetrazolium,innersalt)assays,respectively.TheexpressionofpVAX1-HBs-MFCwasdetectableinthetransfectedHEK293Tcells.TheserumantibodyresponsewaseffectivelyelicitedinBALB/cmiceinjectedwithpVAX1-HBs-MFC.ThehighesttiterofantibodyagainstHCV(MFC)was1:1280,andtheratioofIgG2a/IgG1was1.50±0.12atthefifthweekafterfirstimmunization.Moreover,thecollectedmouseserumantibodyhadtheabilitytocross-reactwiththetwosynthesizedHCVHVR1peptides.ThestimulationindexofthemousesplenocytestoMFCwas1.79±0.07,andtheIFN-γlevelwas287±6pg/mlatweek21afterfirstimmunization.ThehighesttiteroftheantibodyincontrolBALB/cmiceimmunizedwithpVAX1-MFCwas1:320,andtheratioofIgG2a/IgG1was1.33±0.11atweek5post-immunization.Furthermore,thestimulationindexofthemousesplenocytescellstoMFCwas1.52+0.06,andtheIFN-γlevelwas225±9.3pg/mlatweek21post-immunization.TheHBsAggenecanenhancetheeffectsofanHCVmultiple-epitope

简介：ToconstructandexpressthefusionproteinStx2B-IntiminC300ofEHEC0157:H7,andtofurtherinvestigateitsimmunoprophyiacticpotential,thegeneofStx2B(stx2b)fromEHEC0157:H7chromosomewasclonedintopMD18-Tvector.Thereafter,theamplifiedgenewasclonedintoprokaryoticexpressionplasmidpET-28a(+)-eaeC300,whichwasconstructedpreviously.TherecombinantpasmidpET-28a(+)-stx2b-eaeC300wastransformedintoE.coliBL21(DE3).Afterinducement,theproteinStx2B-IntiminC300wassuccessfullyexpressedandanalyzedwithsodiumdodecylsulfatepolyacrylamidegelelectrophoresis(SDS-PAGE),WesternblottingandN-terminalaminoacidresidualsequencing.Toevaluateitsimmunoprophyiacticpotential,itwasprimarilypurifiedbyion-exchangechromatographyandinjectedinto30BALB/cmicewithAl(OH)3inthesubscapularregion.Tendaysafterthelastboostervaccination,20micewereattackedwithEHEC0157:H7lysateandtheprotectiveefficacywasobserved.Inthepresentstudy,thegeneofStx2B-IntiminC300wassuccessfullyclonedintopET-28a(+)vector.TheresultsofSDS-PAGEandWesternblottingassayshowedthatthefusionproteinwassuccessfullyexpressedintheinclusionbodyform,accountingfor25%oftotalexpressionproducts,anditsmolecularweightwasabout43kDa.TheresultoftheN-terminalaminoacidresidualsequencingshowedthatitwasidenticaltothatofthemoleculardesigned.Thepuritywasabout75%afterprimarypurification.AnimaltestsrevealedthatthefusionproteinStx2B-IntiminC300haselicitedhightiterofprotectiveantibodyrelatively.TheseresultsdemonstratethatthefusionproteinStx2B-IntiminC300issuccessfullyexpressedinprokaryoticexpressionsystemandshowscertainimmunoprophyiacticpotential.

简介：TherRNAgeneticlocusisfoundinallprokaryoticorganisms,andishighlyconservative,althoughitsrelativelystablevariationsarefoundfrequentlyindifferentbacteria.Theutilityofthislocusasataxonomicandphylogenetictoolhasbeenreportedwidely.Thisstudy,aimedat16SrRNAgene(16SrDNA)andwiththehelpofbiomolecularmethods,attemptedtoachievethegoalofrapididentificationofcommonpathogensInthisstudy,333clinicalisolatedpathogenicbacteriawerecollected。TwopairsofprimerswerechosenandlabeledwithdifferentfluorescentdyesandthenusedtoamplifythegenomicDNAextractedfrombacteria.ThePCRproductswerethendetectedbycapillaryelectrophoresis-singlestrandconformationpolymorphism(CE-SSCP).Inordertopursuehigherresolutionandpeak-separationeffect,ahighefficientseparatingmedium,linerpolyacrylamidedel(LPA),wasputtouseinthisstudy.Finally,everybacteriacolonygenerateddistinctpatternsfromeachother,whichwereeasilytobeusedforidentification.TheseresultsindicatedthatPCR-CE-SSCPwasarapididentificationmethodforbacterialidentification,withtheaspectsofhighefficiencyandhighprecision.Comparedwithtraditionalmethod,thistechnologyisofgreatutilityforclinicaluseespeciallyforitshighsensitivity.

简介：ThegenomeoftheenterohemorrhagicEscherichiacoliO157:H7EDL933contains177“O”-islands(OIs).TostudytheirpotentialcontributiontotheO157-specificpathogenicity,wesurveyedthedistributionof22OIsbyPCRandDNAhybridizationin17isolatesofShigatoxinproducing(Stx-positive)E.coliO157:H7,andcomparedwiththeirdistributionin21isolatesofStx-negativeE.coliO157and21isolatesofnon-O157entericpathogens.Fourteenof22OIswerepresentinnon-O157entericpathogensanalyzed.Eightof22OIswerefoundonlyinthe17Shigatoxin-(Stx)positiveE.coliO157:H7isolates,buttheywereabsentfromthe21Stx-negativeE.coliO157:NMandO157Hundisolatestested.Amongthe8OIs,onlyOI43orOI48wereexclusivelydetectedinStx-positiveE.coliO157:H7,absentfromneitherofStx-negativeE.coliO157andnon-O157entericpathogens,suchasSalmonella,ShigeUa,Citrobacter,Vibriocholera,enteropathogen-icE.coli(EPEC),enteroadherentE.coli(EAEC),enteroinvasiveE.coli(E1EC)andenterotoxingenicE.coli(ETEC).TheOI43andOI48are83kbinsizeandidenticalinDNAsequences,whichencodegenesforurease,telluriteresistanceandadherence.ByanalyzingtheirjunctiongeneswithPCRandDNAhybridization,wefoundthat21ChineseisolateshaveOI48only.However,for7Japanesepatientisolates,4haveOI43and3haveOI48;forAmericanisolates,2havebothofO143andOI48,2haveOI48only.ThesedataconfirmedthehighlyplasticityofthepathogenicE.coligenome.TheuniquepresenceofOI43/OI48inStx-positiveE.coli0157:H7denotesitscriticalroleinthepathogenicityspecifictothispathogen.