简介：ToexplorethemechanismoftheinhibitionofHIV-1byMycoplasmafermerttans,culturesupernatantsandthallodicproteinsfromM.fermerttansPG18werepreparedandtheproteincomponentsofthesupernatantswerepurifiedwithhighperformanceliquidchromatography(HPLC).Theinhibitoryactivitiestoreversetranscriptase(RT)andthenucleaseactivitiesweredetected;theinfluenceofM.fermerttansonIL-10secretionbybothnormalandH1V-1infectedhumanPBMCweredetermined,andtheinhibitoryeffectofrhIL-10onH1V-1replicationwasdetectedwithEI,ISAmethod.Theresultsshowedthatthepurifiedproteinswithamolecularweightof67-100kDaor10-25kDashoweda36%or34%inhibitoryac-tivitytoRTandpartialnucleaseactivity.ThethallodicproteincouldinducebothnormalandH1V-1infectedPBMCtosecretIL-10remarkably,andtothelatter,thiseffectwasmoreapparent.WhilerhIL-10couldinhibitreplicationofH1V-1inPB-MCinvitroinadose-dependantmanner.ItconcludesthattheinhibitoryeffectoftheM.fermentansPG18culturesupernatantsonRTandthepromotingeffectofPG18thallodicproteinonIL-10secretioninPBMCexplainthemechanismsofinhibitiontoHIV-1byM.fermentansPG18.

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简介：Toexploretheprevalenceoftheplasmid-mediatedquinoloneresistancegeneqnrAinGram-negativebacteriaandtoinvestigateitsmoleculargeneticbackgroundandresistanceprofileinisolatesharboringthisgene,atotalof629nalidixicacid-resistantisolatesofnon-repetitiveGram-negativebac-teriawerecollectedfromclinicalspecimensbetweenApril2004andApril2006andtheseisolateswerescreenedforqnrAgenebyPCRusingspecificprimerscombinedwithDNAsequencing.Theextendedspectrumβ-lactamase(ESBL)orAmpC-producingisolatesweredistinguishedbythephenotypicconfir-matorytestcombinedwithDNAsequencing,andtheantibioticssusceptibilitytestforqnrA-positiveiso-lateswascarriedoutbyKirby-BauerandE-testmethod.TodetectthelocationoftheqnrAgene,plas-midconjugationandSouthernhybridizationwereperformedandtheintegronstructurecontainingtheqnrAgenewasclonedbyPCRstrategyandsequencedbyprimerwalking.ItwasdemonstratedthattheincidenceoftheqnrA-positivestrainsinnalidixicacid-resistantbacteriawas1.9%(12/629),inwhichthedetectionratesforKlebiesiellapneumoniae.Enterobactercloacae,Enterobacteraerogenes,CitrobacterfreundiiandSalmonellachoeraesuiswere2.2%(3/138),17.1%(6/35),9.1%(1/11),12.5%(1/8),and14.3%(1/7),respectively.TheqnrAgenewasfoundtobeembeddedinthecomplexsu/1-typeintegronlocatedonplasmidswithvariedsize(80-180kb).Amongthem,4qnrA-positiveisolatescarriedintegronIn37and8isolatescarriedanovelintegron,temporarilydesig-natedasInX.AlltheqnrA-positiveisolateswereESBL-producingandtransferableforthemuhi-drugresistance.Itisconcludedthattheplasmid-mediateddrug-resistancemechanismexistsinthequinoloneresistantstrainsofisolatesfromhospitalsinGuangdongarea,buttheincidencewasratherlow.Never-theless,itisstillpossiblethatthehorizontaltransferoftheresistantqnrAgenemightleadtothespreadingofdrug-resistance.

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