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简介：

简介：ToestablisharapididentificationmethodforcommonpathogenicbacteriaonthebasisofmolecularbiologyandtoconstructapreliminaryPolymeraseChainReaction-CapillaryElectrophoresis-RestrictionFragmentLengthPolymorphism(PCR-CE-RFLP)databaseofbacteriaisolatedfromclinicalspecimensfrequently,183strainscollectedfromclinicalsamplesbelongingto12generaand19specieswhosebiochemicalcharacterizationscorrespondedtothetypicaloneswereexamined.ThegenomicDNAswereamplifiedbytwopairsoffluorescencelabeledprimersaimingat16SrRNAgeneand16S-23SrRNAspacerregiongenerespectivelyatthesametime.PCRproductswerethendigestedbyrestrictionendonucleaseHaeⅢin-completelybeforetakingcapillaryelectrophoresis.TheresultswiththePCR-CE-RFLPpatternsof16SrRNAgeneswerejustalikewithinsomegenera,butwhenitcomesto16S-23SrRNAspacerregiongenes,eachbacteriumshowedauniquepattern,whichcanbedistinguishedfromeachothereasily.ItseemsthatPCR-CE-RFLPpatternsof16SrRNAgenecouldonlybeusedtoclassifythebacteriaintofamilylevel,whereasthedataof16S-23SrRNAspacerregiongenecouldbeutilizedtoidentifythewholemicroorganismsaspreciselyasthespecieslevel.Inspiteofthedataofthespacerregiongenealonecanbesufficientlytoverifythewholebacteria,weinsistthatthe16SrRNAgenecouldbeofsomeassistantincasethatthereshouldbelotsoffamiliesofbacteria,inwhichsomesimilarones,withthesameRFLPdataof16S-23SrRNAspacerregiongene,maycoexist.ThisstudyprovesthattheutilityofPCR-CE-RFLPisaconvenient,rapidmethodtoidentifypathogenicbacteria,andisalsoaquickdiagnosismeasureforapplicationtoclinicaluse.

简介：Inthepresentstudy,thedrug-resistancegenesencodingβ-lactamases,aminoglycosidemodifyingenzymes,DNAtopoisomerasesandintegronaswellastheirmolecularepidemiologywereinvestigatedbymeansofanalyzingthedrug-resistanceandmolecularepidemiologyofAcinebacterbaumanniiisolatedfromtheclinicalsamplesintwohospitalsinQiangzhouandHuzhoucityofJiangsuandZhejiangprovincefromJuly2000toMarch2005.Theminimalinhibitoryconcentrations(MICs)ofthese307isolatesweredetectedbyautomaticmicrobiologicalsystem,and35strainsagainst5-fluoro-quinoloneswereperformedbyagardilutionassay.Meanwhile,theresistantgenesin80isolateswereamplifiedbyPCRwithidentificationbyDNAsequencer.Itwasfoundthatmostofthe307isolatesofA.baumanniiwereresistanttomultipleantibioticstested,inwhichtheresistanceratesoftheisolatesagainstpiperacillin,piperacillin/tazobactam,amoxacillin/clavulanicacid,cefotaxime,ceftazidime,cefepime,gentamicin,amikacin,ciprofloxacin,chloramphenicolandsulfamethoxazole/trimethoprimwereallabove35%,butthoseofimipenemandmeropenemwerequitelow,rangedonly2.6%and3.3%.Inaddition,itwasalsodemonstratedthatthepositiveratesofTEMandSHVβ-lactamasegenesaccountedfor93.8%and22.5%respectively,andthoseoftheaminoglycoside-modifyingenzymegenesincludingaacC1,aacC2,aacC3,aacC4,aacC4A,aphA6,ant(2')-Iandant(3')Iwere58.8%,8.8%,7.5%,28.8%,45.0%,2.5%,28.8%and65.0%respectively.Themutationsinthequinolone-resistantdeterminingregion(QRDR)ofgyrAandparCgenesindicatedthatsubstitutioninSer-83residueofGyrAproteinwasmostfrequentlyoccurredamongstrainswithMICforciprofloxacinofmorethan4μg/ml,whereasadoublemutationatSer-83residueofgyrAandSer-80ofparCwasfoundinstrainswithMICofciprofloxacinofmorethan8μg/ml.Astothepositiveratesofclass1integron(IntI-1)andqacE△1-sul-1,itwasfoundtobe60.0%and77.5%respectively