简介：TostudythegeneticcharacterizationoffourstrainsofBorreliaburgdorferiisolatedinChina.PCRtechniquewasusedtoamplifythe5S-23SrRNAintergenicspacerDNAfromthewholecellularDNAofisolatedGXLD-4,9,18andChang14,andthentheamplifiedproductswereclonedintoplasmidpGEM-TEasyandsequenced.Itwasfoundthatthe5S-23SrRNAintergenicspacerDNAofthefourisolateswas242bp,revealingthenucleotidesequenceidentityofmorethan99%.ThefourisolateshadhighersequenceidentifywithBorreliavalaisianathanwithothergeneticgroups.ThesefourisolatesmostlikelybelongtoBorreliavalaisianagenomicgroup.

简介：Toinvestigatetheprevalenceandgenotypeofextendedspectrumbeta-lactamases(ESBLs)mediatedbyplasmidinGram-negativebacteriafoundinsouthernChina,atotalof1184clinicalisolatesofnon-repetitivestrainsofGram-negativebacteriawerecollectedin2001from5differentcitiesinsouthernChina.TheESBLs-producingisolatesweredistinguishedbymeansofthephenotypeconfimatorytestbasedontheNCCLScriteriaandweresubjectedtoplasmidconjugationandelectroporationexperiments.Thoseclinicalisolatessucceededinplasmidtransfershadundergoneplasmidconjugationandelectro-transformation,plasmidDNAextractionandPstⅠdigestlinger-printinganalysis,aswellasthetmiversalprimerPCRamplificationoftheTEM,SHV,CTX-M,VEB,PERandSFOgenesandtheDNAsequencinginordertodeterminethegenotypesofESBLsandtheirplasmidlocations.ItwasfoundthattheincidenceoftheESBLs-producingstrainsofGram-negativebacteriawas14.6%(173/1184)with67strainsoftransconjugantsand11strainsofelectro-transformants,inwhichCTX-M-14typewas33.3%(26/78);CTX-M-3typewas23.1%(18/78);CTX-M-9typewas14.1%(11/78);CTX-M-5typewas6.4%(5/78);CTX-M-13typewas2.6%(2/78);SHV-5typewas7.7%(6/78);SHV-12typewas5.1%(4/78),SHV-2atypewas2.6%(2/78)andunidentifiedtypewas5.1%(4/78).29.5%ofthewildstrainsalsocarriedbroad-spectrumbeta-lactamasesTEM-1andSHV-1types.TheabovementionedESBLsgeneswerelocatedontransferableplasmidswithvariablesizes(from35to190kb).TheCTX-MtypeESBLswascharacterizedbyhigh-levelofresistancetocefotaxime.ItconcludedthattheCTX-M-typewasthemostprevalentgenotypeinclinicalisolatesofGram-negativebacteriainsouthernChina,andtheSHVtyperanksinthesecondplace.TEM-,VEB-,Toho-andPER-typeswerenotfoundintheseisolates.

简介：During2004,atotalof124batchesofHIVantibodyELISAsfromdomesticandoverseasmanufacturers,comprisingapproximately60milliontests,weretestedforqualityandreleasedforscreeningbloodinChina.Theinter-andintra-batchvariation,specificity,andsensitivitywereevaluatedusingalaboratorypanelandclinicalsamples.Theinter-batchvariationwaslessthan15%andonly2of12assayshadintra-batchvariationoflessthan20%for4dilutionsofacontrolspecimen.257samplesconfirmedpositiveforHIVantibodyand4826negativesamplesfromdifferentregionsinChinawereusedtoevaluatethesensitivityandspecificityoftheassays.Theresultsshowedthatthesensitivityisintherangefrom93.7%to100%forassayssampleddirectlyfromthemanufacturers,and91.4%-99.6%forthoseretrievedfromtheconsumers;thespecificitywasintherangefrom97.88%to99.97%.ThetestingenvironmentmayvaryindifferentregionsofChina.Therefore,manufacturersshouldproviderobustassaystosatisfytherequirementsofthesediverseenvironments,andespeciallyreducetheintra-assayvariationandimprovethestabilityofthekits.

简介：

简介：摘要：目的：掌握浙江省长兴县食源性疾病发病的流行病学特征，为制定针对性的防控措施提供依据。方法：收集2014-2022年长兴县重点监测点的食源性疾病监测数据进行统计分析，采集患者粪便标本进行副溶血性弧菌、沙门菌、志贺菌、致泻大肠埃希菌和诺如病毒检测。结果：共收集4514例病例，发病时间集中在5-10月（62.89%，2839/4514），26-35岁组发病最高（26.03%，1175/4514），职业以农民最多（35.95%，1623/4514），可疑暴露食物主要为水产动物及其制品（19.49%，880/4514）和肉与肉制品（18.81%，849/4514），可疑的加工及包装方式主要是餐饮服务业（42.16%，1903/4514）。监测病原体中致泻大肠埃希菌检出率最高12.70%（387/3048），各种病原体之间检出率有差异（ =682.48，P＜0.05）。结论  浙江省长兴县食源性疾病发病以夏季最多，高发人群为青壮年，职业以农民最多，可疑暴露食品以水产动物和肉类食品为主，应进一步针对高发人群、高发季节和主要致病病原体做好食源性疾病防控工作。

简介：

简介：Toinvestigatetheexistenceofthemajoroutermembranepmtein(MOMP)geneLip132in15dominantChinesestrainsof15semgroupsofLeptospirairaerrogansand2intemationalstrainsof2semgroupsofLeptospirabiflexa,andtocloneandconstructtheexpressionsystemaswellastoidentifytherecombinantpmteins,genomicDNAsfromstrainsofleptospirawerepreparedbymutinephenol-chloroformmethod,andthefragmentsoftheLipL32genewiththewholelengthfromthestrainswereamplifiedwithhighfidelityPCR.Thetargetamplificationproductswere,sequencedafterT-Acloning,andtheexpressionsystemforthegenesweretherebyconstructed,ExpressionoftherecombinantproteinswasidentifiedbyusingSDSPAGEafterinductionwithIPTGatdifferentdosages.WesternblotassayswithrabbitantiserumagainstthewholecellofTR/PatocⅠofLeptospiraandimmunizedserumwithrMOMPswereusedtodeterminetheimmunoreactivityandimmunogenicityoftherecombinantproteins.Microscopicagglutinationtestwasusedtodeterminethecross-agglutinationtitresinrabbitseraimmunizedwithrMOMPs,andthecelladherencemodelofLeptospirawasusedtoexaminetheblockingeffectsofrabbitantiseraagainsttheserMOMPs.ItwasfoundthattheLipL32genecouldbefoundinallthe17strainsofLeptospiramentionedabovewithtwodifferentgenotypes,i.e.LipL32/1andLipL32/2.AmountsofexpressionsofrMOMP1andrMOMP2afterIPTGaccountedfor40%and10%ofthetotalbacterialpmteinsrespectively.BothrMOMP1andrMOMP2couldcombinewiththerab-bitantiserumagainstleptospiralTR/PatocⅠ,andcouldinducetheproductionofagglutinationantibodiestothese17strainsofLeptospirawith1:2to1:64MATtitres.Therabbitanti-rMOMP1andanti-MOMP2antibodiesat1:2to1:16dilutionscouldefficientlyblockadherenceofLeptospira.ItconcludesthatalltheLeptospiratestedinthepresentstudypossessLipL32/1orLipL32/2genes,andtheconstructedexpressionsystemcanexpresstherMOMP1andrMOMP2.

简介：TherelationshipbetweenembBmutationofMycobacteriumtuberculosisandethambutol(EMB)resistanceoftheclinicalisolatesoftuberculouspatientsinChinawasinvestigatedbyreversedotblothybridization(RDBH)inadditiontoevaluatingtheclinicalvaluewithapplicationofPCR-RDBHtechniquetodetectEMBresistance.Inthepresentstudy,thegenotypesofthe258bpfragmentsofembBgenesfrom196clinicalisolatesofM.tuberculosiswereanalysedwithRDBHandDNAsequencing.Itwasdemonstratedthat60outof91phenotypicallyEMB-resistantisolates(65.9%)showed5typesofmissensemutationsatcodon306ofembBgene,resultinginthereplacementoftheMetresidueofthewildtypestrainwithVal,IleorLeuresidues.Inthesemutations,theGTPmutation(38/91,41.8%)andtheATAmutation(16/91,17.6%)werethemostencounteredgenotypes.TheembBmutationatcodon306couldalsobefoundin69isolatesofphenotypicallyEMB-sensitivebutresistanttootheranti-tuberculousdrugs,butnosuchgenemutationcouldbefoundin36strainsofdrug-sensitiveisolates.Meanwhile,theconcordancewiththeresultsofDNAsequencingforonewide-typeprobeand5probesforspecificmutationswas100%.ItwasconcludedthattheEMB-resistanceoccurringinmostM.tuberculosisisduetoappearanceofembBmutationatcodon306,andthePCR-RDBHassaywasprovedtobearapid,simpleandreliablemethodforthedetectionofgenemutations,whichmightbeagoodalternativeforthedrug-resistancescreening.