ResearchBriefGiardiaduodenalis:Improveddetectionofviablecystsbyreversetranscription-PCRofheatshock-induciblehsp70geneGyu-CheolLeea,*,Se-HeeNama,Jong-ChanChaeb,Chan-HeeLeecaWaterAnalysisandResearchCenter,K-Water,Daejeon306-711,RepublicofKoreabDivisionofBiotechnology,CollegeofEnvironmentalandBioresourceSciences,ChonbukNationalUniversity,Iksan570-752,RepublicofKoreacSchoolofLifeSciences,CollegeofNaturalSciences,ChungbukNationalUniversity,Cheongju361-763,RepublicofKoreaarticleinfoArticlehistory:Received12March2009Receivedinrevisedform14August2009Accepted18August2009Availableonline22August2009Keywords:GiardiaduodenalisRT-PCRhsp70HeatshockabstractGiardiaduodenalisisawaterborneprotozoanparasitethatcausesthediarrhoealdisease,giardiasis.Itsdurableandthickcellwallallowstheparasitetoexhibitresistancetoenvironmentalstresses.BecauseG.duodenalisexistsinawatersystematlowlevels,itisnecessarytodevelopasensitivemethodtodetectitsviabilityinaquaticenvironments.Inthepresentstudy,specificprimersfortheheatshockprotein(hsp)70geneweredesignedonthebasisofG.duodenalisgenomesequenceandbioinformaticanalysis.ViableG.duodenaliscystsweresuccessfullydistinguishedbyreversetranscription-PCR(RT-PCR)analysisusingtheseprimers.Theampliconofhsp70wasobtainedfromonecystofG.duodenalis/100ll,andthisdetectionsensitivitysignificantlyincreasedby103-foldwhenthecystsweregivenheatshocktreatment.ThesefindingsprovethatviableG.duodenaliscystsweresuccessfullydetectedwithahighdegreeofsen-sitivitybyRT-PCRanalysistargetingthehsp70geneofG.duodenalis,therebysuggestingitspracticalpotentialfordetectingviableG.duodenalisinenvironmentalsamples.�2009ElsevierInc.Allrightsreserved.1.IntroductionIthasbeenwellestablishedthatGiardiaduodenalis—awater-borneprotozoanparasite—causesgiardiasisinassociationwithCryptosporidiumparvum(C.parvum),whichcausescryptosporidi-osis(Adam,2001;Berkmanetal.,2002).G.duodenaliscausesgas-troenteritis,suchasnonbacterialdiarrhoea,andisreleasedintoriversorlakesviathefaecesofitshostssuchashumanandmammals...
