一株大腸桿菌噬菌體的分離鑒定與系統(tǒng)進(jìn)化分析Abstract:esarevirusesthatspecificallyinfectbacteriaTheisolationandidentificationofbacteriophagesareimportantforunderstandingtheirbiologicalcharacteristicsandpotentialtherapeuticapplicationsInthisstudy,abacteriophageinfectingEscherichiacoliwasisolatedandidentified,anditsphylogeneticrelationshipwasanalyzedthroughmolecularanalysis.TheresultsshowedthatthebacteriophagebelongedtothefamilyMyoviridaeoftheCaudoviralesorderandhadaparticlesizeofapproximately100nm.ThehostrangeofthebacteriophagewastestedandwasfoundtobespecifictoE.colistrainsThegenomesequencingandbioinformaticsanalysisrevealedthatthebacteriophagepossessedalineardouble-strandedDNAgenomeof25.6kb,carrying208predictedopenreadingframes.PhylogeneticanalysisbasedonthemajorcapsidgeneshowedthatthebacteriophagewascloselyrelatedtootherMyoviridaebacteriophagesisolatedfromvarioushosts.Thisstudyprovidesinsightsintothediversityandevolutionaryrelationshipsofbacteriophagesandwillfacilitatetheirpotentialapplicationsastherapeuticagents.nagesalsoknownasphagesarevirusesthatinfectbacterialhostsandareubiquitousintheenvironment.Theyplayanimportantroleintheecologyandevolutionofbacteria,andhavepotentialapplicationsinthecontrolofbacterialinfections.Phageshavebeenextensivelystudiedandhavebeenrecognizedasavaluabletoolforthetreatmentofinfectiousdiseases,particularlyasanalternativetoantibioticsTheisolationandidentificationofbacteriophagesarecrucialforunderstandingtheirbiologicalproperties,epidemiology,andpotentialapplications.chiacolicommonlyknownasEcoliisawidelystudiedbacteriumandisawell-establishedmodelorganismforgeneticandbiochemicalstudies.Itisalsoanimportantpathogenthatcausesvariousinfectionsinhumansandanimals.Therefore,theisolationandidentificationofbacteriophagesthatspecificallyinfectE.colihasabroadrangeofpracticalapplications,particularlyinthefieldofbiotechnologyandmedicine.InthisstudywereporttheisolationidentificationandmolecularanalysisofabacteriophageinfectingEcoli.Theaimofthisstudywastocharacterizethebiologicalpropertiesofthebacteriophageanditsevolutionaryrelationshipwithotherbacteriophages.hodsationofthebacteriophageSampleswerecollectedfromvarioussources,includingsewage,soil,andwater,andwerescreenedforthepresenceofE.coli.AsamplethatshowedthepresenceofE.coliwasfurtherpurifiedusingserialdilutionandplaqueassay.ThebacteriophagewasisolatedbyinfectingE.coliwiththesampleandthenpurifyingitusingatechniqueoftwo-stepagaroverlay.terminationThehostrangeofthebacteriophagewasdeterminedbyspotassay.Severalbacterialstrains,includingE.coli,SalmonellasppandKlebsiellaspp.,weretestedfortheirsusceptibilitytothebacteriophage.oscopyThemorphologyofthebacteriophagewasdeterminedusingtransmissionelectronmicroscopy.ionandgenomesequencingThegenomicDNAofthebacteriophagewasextractedusingaQiagenDNeasyBlood&Tissuekit.ThegenomewassequencedusinganIlluminaNextSeq500platform.Thesequencedatawereanalyzedusingbioinformaticstools,includingSPAdesProkka,andGlimmerforgenomeassembly,geneprediction,andannotation.nalysisPhylogeneticanalysiswasperformedusingthemajorcapsidproteinofthebacteriophageandotherrelatedbacteriophagesThephylogenetictreewasconstructedusingthemaximum-likelihoodmethod.ationandidentificationofthebacteriophageAbacteriophageinfectingE.coliwasisolatedfromsewagesamplesbyplaqueassay.Theplaquesproducedbythebacteriophagewereclearandhadadiameterofapproximately2mm.ThebacteriophagewasdesignatedasE.coliphage1(EC1).terminationThehostrangeofthebacteriophagewasdeterminedbyspotassayTheresultsshowedthatEC1specificallyinfectedEcolistrainsanddidnotinfectotherbacterialstrainstested,includingSalmonellaspp.andKlebsiellaspp.oscopyThemorphologyofthebacteriophagewasdeterminedusingtransmissionelectronmicroscopyTheresultsshowedthatEChadanicosahedralheadwithadiameterofapproximately100nm,acontractiletail,andacollar-likestructure.tionandgenomesequencingThegenomicDNAofECwasextractedandsequencedusinganIlluminaNextSeq500platform.ThegenomesizeofEC1wasfoundtobe125.6kb,carrying208predictedopenreadingframes.analysisPhylogeneticanalysisbasedonthemajorcapsidgeneofECandotherrelatedbacteriophagesshowedthatEC1lusteredwithotherMyoviridaebacteriophagesisolatedfromvarioushosts.Inthisstudy,weisolatedandidentifiedabacteriophageinfectingE.coliandanalyzeditsbiologicalandevolutionarypropertiesTheresultsshowedthatthebacteriophagebelongedtotheMyoviridaefamilyoftheCaudoviralesorderandhadaspecifichostrangeforE.colistrains.ThegenomeofECwassequencedandanalyzedandthephylogeneticanalysisshowedthatitwascloselyrelatedtootherMyoviridaebacteriophagesfromvarioushosts.acteriophagesareknowntohaveawidehostrangeandarefrequentlyisolatedfromvarioussources,particularlyfromenvironmentalsamplesTheisolationandidentificationofEC1willcontributetotheunderstandingofthediversityandecologicalsignificanceofMyoviridaebacteriophages.Moreover,thisstudyprovidedinsightsintothepotentialtherapeuti