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β-glucanandE.coliinfectionIntroductionEscherichiacoliiscommonlyfoundintheaviangastrointestinaltractandothermucosalsurfaces.AlthoughmostofthestrainsarecommensalsaseparategroupdesignatedavianpathogenicE.colihastheabilitytocauseextraintestinaldiseaseinpoultrycollectivelycalledcolibacillosisKariyawasametal.2006;Bonnetetal.
2009.SerotypesO1O2andO78andtosomeextentO15andO55arethemostcommonserotypesassociatedwithcolibacillosisfoundinchickensGomisetal.1997;Rajietal.
2007.TheycommonlycauseairsacculitispericarditisperihepatitisperitonitissalpingitisandsubsequentlythemostacuteformsepticemiaresultinginsuddendeathMellataetal.2003;Asketal.
2006.Thepoultryindustriesworldwidesuffergreatfinanciallosseseveryyearbecauseofthehighmorbidityandmortalityratescausedbycolibacillosis.Treatmentstrategiesincludethecontrolofenvironmentalfactorsandtheuseofantibiotics.HoweverconcernsexistregardingtheemergenceofantibioticresistanceofnormalmicrofloraandpathogenicbacteriawhichmayinturnthreatenhumanhealththroughtransferfdrugresistancegenestozoonoticbacteriaFoodandgricultureOrganizationoftheUnitedNationsWorldealthOrganizationandWorldOrganizationforAnimalealth
2003.AviancolibacillosisadiseasecausedbyagroupofbacteriacalledavianpathogenicEscherichiacoliAPECinchickensturkeysandotheravianspeciesisaninfectiousdiseasethatoftencausesseveremortalityandsubsequentlyresultsineconomiclossestothepoultryindustryGibbsetal.
2004.ThediseaseisassociatedwithacompletesetofsyndromesincludingsepticemiaairsaculitispericarditisandswollenheadsyndromeChevilleandArp1978;Rodriguez-Sieketal.
2005.SeveralE.coliisolatesarecommonlyassociatedwithcolibacillosisinpoultryandtheserogroupsO1O2andO78havebeenrecognizedasthepredominantsourcesinvolvedinthisdiseaseWhittamandWilson1988;McPeakeetal.
2005.AhighraAhighrateofantibioticresistancewasobservedwhiletestingtheseserogroupswhichprobablyoriginatesfromtheextensiveuseofantibioticsinthepoultryindustryAllanetal.1993aswellasbyacquisitionofRplasmidsJohnsonetal.2005b;Skybergetal.
2006.Numerousconcernsabouttheuseofantibioticsinthepoultryindustryhavebeenraisedincludingthefurtherselectionofdrug-resistantstrainsFranklin1999;Anguloetal.
2004.TherearealsohumanhealthissuesinvolvedduetothepotentialtransferofE.colifromanimalsviathefoodchainAnguloetal.2004;Johnsonetal.2005a.Thishasattractedconsiderableattentionfromresearcherswhoareseekingalternativesforcontrolandtreatmentofcolibacillosisinanimals.OnepromisingalternativetoantibioticsistheuseofvirulentbacteriophageagainstE.coliserogroupsO1O2andO78awell-establishedapproachthatphagesfortheseserogroupsareabletobeisolatedandusedinphagetherapyagainstbacterialcells.BacteriophagesareaclassofvirusesthatliveandreplicateinbacteriaAckermann2000andhavetheabilitytoattackasinglespeciesorsubsetofaspeciesofbacteriummakingthempotentialantibacterialagents.β-Glucanshavebeenwellstudiedinhumanandanimalsubjectsandtheirimmune-enhancingeffectshavebeenwellnotedVolmanetal.
2008.Duetotheirabilitytoaugmenttheimmuneresponseβ-glucanshavebeentermedbiologicalresponsemodifiers.β-Glucansarestructuralcomponentsofthecellwallofmanybacteriafungiandyeastaswellascerealgrainssuchasoatandbarley.β-GlucansfromfungalandyeastsourceshavebeenwidelystudiedandshowntobemosteffectiveinenhancingprotectiveimmunityagainstinfectiousagentsSoltanianetal.
2009.Thoughtheimmune-enhancingcapabilitiesofβ-glucanshavebeenproveninmammalslimitedreportedresearchisavailableforpoultrywithmixedresultsintermsofperformanceandimmuneresponse.Somestudieshaveshownthatβ-glucansupplementationimprovesBWZhangetal.2008whereasothergroupshavefoundnosignificanteffectsChaeetal.
2006.Huffetal.2006reportedcontradictoryresultsinwhichβ-glucansupplementationwasdetrimentaltoBWinanonchallengesettingbutwasfoundtobebeneficialduringanEscherichiacolichallenge.Thesevaryingresultsindicatethatmoreresearchneedstobecarriedouttodeterminetheoptimaldosageandproperusageofβ-glucanstoobtainconsistentresults.β-Glucanshavebeneficialeffectsonboththeinnateandadaptiveimmunesystems.Whenexposedtoβ-glucansinvitrochickenmacrophagesandsplenocyteshavebeenshowntoexperienceenhancedproliferationandimprovedphagocyticcapabilitiesChenetal.2003;Guoetal.
2003.Intermsoftheadaptiveimmuneresponseβ-glucansmagnifyplasmaIgGandIgAlevelsindicatinganupregulationofthehumoralimmuneresponseZhangetal.
2008.TheT-lymphocytesubpopulationsarealsoaffectedwithhigherCD4+CD8+andCD4+:CD8+T-cellpopulationsfoundinchickenssupplementedwithβ-glucanChenetal.2003;Chaeetal.
2006.Furthermoreβ-glucanshavedemonstratedtheabilitytoaugmentthesecretionofseveralcytokinestoaidinpathogenelimination.Macrophagesisolatedfrombirdsfedβ-glucansdemonstratedenhancedinterleukinIL-1Guoetal.2003IL-2andinterferonIFN-γlevelsZhangetal.
2008.Dietaryβ-glucanhasalsobeenshowntoincreasethesizeoftheprimaryandsecondarylymphoidorgansprovidingfurtherevidenceoftheirimmunomodulatingcapabilitiesGuoetal.2003;Zhangetal.
2008.MaterialsandmethodsExperimentalAnimalsandTreatmentsA3-wkexperimentwasconductedtodeterminetheefficacyofbacteriophageEC1intreatingrespiratoryinfectioninbirdscausedbyE.coliO78:K
80.Atotalof480one-day-oldmalebroilerchicksRoss308wereobtainedfromacommercialhatchery.Thechickswereassignedrandomlyto4treatmentgroupseachwith4pensof30chicksperpen.Waterandbroilerfeedantibioticfreewereprovidedadlibitumthroughouttheexperimentalperiod.The4treatmentgroupsweregroupIcontrolinwhichuntreatedunchallengedbirdswereadministered
0.2mLofPBSonly
0.14MNaCl
0.0027MKCl
0.01MNa2HPO
40.0018MKH2PO4;pH
7.4;groupIIcontrolinwhichunchallengedbirdsweretreatedwith
0.2mLofbacteriophageEC11011pfu/mL;groupIIIinwhichbirdswerechallengedwith
0.2mLofa5-h-oldE.coliO78:K80culturegrowninLuria-Bertanibrothat37°Candshakenat180rpmcontaining109cfuofbacterialcells/mLfollowedby
0.2mLofbacteriophageEC11011pfu/mLat2hpostchallenge;andgroupIVinwhichbirdswerechallengedwith
0.2mLofa5-h-oldE.coliO78:K80culturecontaining109cfuofbacteriacells/mLonly.Thetimepointatwhichtoinoculatethebacteriophage2hpostchallengewasselectedbasedontheresultsofapreliminarytrialshowingthatE.coliO78:K80hadcolonizedthelungsandthatthebacteriahadspreadtootherorganssuchastheliverandheart2hafterthebirdswerechallengedwiththepathogendatanotshown.Allthematerialswereinoculateddirectlyintothetracheaofthe1-d-oldchicksbyusingafeedingneedleinafarmsettingTheBWoflivebirdsweretakenweekly.Samplingwascarriedoutond0beforeinoculationofE.coliorbacteriophageEC1123714and21from3ofthepensofeachtreatmentgroup.Thelastpenwasusedfortheobservationofmortalityrate.Oneachsamplingday6birdsfromeachgroup2randomlyselectedfromeachofthe3samplingpenswereweighedandkilledbyCO2inhalationforlaboratoryexamination.Birdsthatdiedonthesamplingdaywerealsodissectedandsubjectedtothesamelaboratoryexaminations.AllanimalmanagementandsamplingprocedurescompliedwiththeguidelinesoftheGuidefortheCareandUseofAgriculturalAnimalsinAgriculturalResearchandTeachingFederationofAnimalScienceSocieties
1999.AnimalsandHousingConditionsAtotalof144specificpathogen-freeSPFchickensValo;Lohmann-TierzuchtCuxhavenGermanyhatchedattheClinicforAvianReptileandFishMedicineUniversityofVeterinaryMedicineViennaAustriawereusedinthestudy.ThechickensweredistributedrandomlyandkeptundercontrolledconditionsinsterilizedisolationunitsMontairAndersenB.V.HM1500SevenumtheNetherlands;size:
1.2m2withtheairflowof30to32m3/h.Thetemperaturewasadjustedat33°Cduringthefirstweekoflifeandlateronreducedgradually2°Cperweekto20°Cbytheageof6wk.Lightperiodwaskeptat12hthroughoutthetrial.FeedandwaterwereprovidedadlibitumInexperimentsbirdswerekeptunderincandescentlightingonalightscheduleconsistingof23hlightand1hdark.TheywereprovidedadlibitumaccesstowaterandanunmedicatedstandardcornandsoybeanbroilerstarterdietthatmetorexceededtheNRCrecommendedallowancesNationalResearchCouncil1994andwhichcontained3000kcalofME/kgand
21.0%CP.BirdswerefedanunsupplementeddietorthesamedietsupplementedwithalowlevelLLof500g/tonne1lb/tonorahighlevelHLof1000g/tonne2lb/tonofastandardizedyeastextractfeedsupplementAlphamune.Individualbirdweightsandfeedconsumptionbypenweredeterminedweekly.Thetemperatureofthecontrolroomwasmaintainedaccordingtoestablishedstandardoperatingprocedures.Broodersweresetat
32.3Cforthefirstweekafterwhichroomtemperaturewasmaintainedat
24.8C
1.5andRHat63
2.3%fortheremainderofthestudyusinganautomatedairhandlingsystem.At7dofageduringthecold-stresstreatmentbirdswerechallengedbycoarsesprayinoculationofeyesandnareswithapproximately3to4×108cfuofanonmotileserotypeO2strainofE.colithathadoriginallybeenisolatedfromchickenswithcolisepticemiaandhasbeenusedtoreproduceturkeyosteomyelitiscomplexHuffetal.
19982000.Theinoculumwaspreparedbyadding2loopsofafresh18-hculturethatwasgrownonColumbiasheepbloodagarat37Cto100mLoftryptosephosphatebrothandincubatingfor
2.5hina37Cshakingwaterbath.Theculturewasseriallydilutedandheldovernightfor18to20hat4Cwhileastandardplatecountwasmadeandcounted.Mortalitydatawerecollectedtwiceeachdayafterchallengeandbirdswereweighedandexaminedforlesionsofairsacculitis.ThefollowingkeymodifiedfromthatdescribedbyPiercyandWest1976wasusedtoscorelesionsofairsacculitisandpericarditisobservedinbothmortalitiesandatnecropsy:0=noinflammation;1=opacityandthickeningoftheinoculatedairsac;2=mildairsacculitisandmildpericarditis;3=moderateairsacculitisorpericarditiswithspreadtoliverorabdominalcavityperihepatitisorperitonitis;4=severefibrinousairsacculitisandseverepericarditis;and5=severeairsacculitisorpericarditiswithspreadtoliverorabdominalcavity.E.coliChallengeCultureTheE.coliusedinthesestudieswereinitiallyisolatedfromthebloodofchickenswithcolisepticemiaBayyarietal.1997;Huffetal.
1998.ThisE.colistrainisserotype02nonmotileandlactosenegative.TheE.coliculturewaspreparedbyinoculationoftryptosephosphatebrothSigmaChemicalCo.St.LouisMOthatwasincubatedinashakingwaterbathfor
2.5h.Theculturewasremovedfromthewaterbathandheldat4°C.Theculturewasenumeratedbymakingduplicate10-foldserialdilutionsofthecultureandbyspread-platingtheappropriatedilutionsinduplicateontryptosephosphateagarplateswhichwereenumeratedafterovernightincubationat37°C.ThechallengeculturesweremadebydilutingthisE.colistockcultureandverifiedwithserialdilutionsofthechallengecultureandenumerationbyspreadplating.PreparationofPathogenicEC.PathogenicECserotypeO2:K1wasculturedovernightinnutrientbrothat37C.Theculturewascentrifugedfor15minat3400×gwashedandresuspendedinPBSpH
7.
4.Bacterialconcentrationwasmeasuredbyaspectrophotometer570nm.Eachchickreceived
0.1mLofbacterialsuspension1×1010cfu/mLinPBS.LaboratoryExaminationsGrossLesionExaminations.Macroscopicexaminationsoftheairsacliverandheartofslaughteredbirdswerecarriedout.Opacityorthickeningoftheairsacandthepresenceoftissuelesionsorfibrinousexudatesontheliverandheartwereconsideredindicativeofairsacculitisperihepatitisandpericarditisrespectively.OrganWeight.Atnecropsythelungliverheartandspleenwereexcisedasepticallyandweighed.TheweightsoftheorganswerereportedasthepercentagerelativetoBWorganweight/BW×100%;Huffetal.2006a.IsolationofE.colifromLungsQuantitativeAnalysis.Thelungsofbirdswereremovedasepticallyweigheddiluted10×inMaximumRecoveryDiluentMerckKGaADarmstadtGermanyandhomogenized.ThehomogenateswerethenseriallydilutedbeforeplatingoneosinmethyleneblueEMBagarMerckKGaA.TheEMBagarplateswereincubatedovernightat37°CafterwhichthemetallicgreensheencoloniesofE.colidesignatedEMB+E.coliwerecountedtodeterminethenumberofE.colicfu/gcolonizingthelungs.ThepopulationsofEMB+E.coliinlungsamplesfrombirdsinthedifferenttreatmentgroupswerethencomparedtodeterminetheseverityofinfection.IsolationofE.colifromOrgansandBlood.BloodsamplesofbirdswerecollectedbycardiacpunctureandculturedonEMBagar.Theliverheartandspleenofeachbirdwerecutopenandtheinnerpartsoftheseorganswereswabbed3to4timeswithsterilecottonbudsandplateddirectlyonEMBagar.Theplateswerethenincubatedat37°Cfor16to18handthepresenceofE.colicoloniesdesignatedEMB+E.coliwasdetermined.ScoringSchemeandLaboratoryProceduresClinicalScores.Thehealthstatusofthebirdswasscoredfrom0to4onthebasisoffollowingcriteria:0=animalactivewithnoclinicalsymptoms;1=slightlyweakdroppingwingsdiarrhea;2=depressedwithswollencrop;3=weakwithruffledfeathersreluctanttowalkandapathy;and4=animalunabletomoveorstandeyesclosedandintensebreathing.Thehealthstatuswasscoreddailyfromdayofinoculationtothedayofterminationofexperiment.GrossPathologicalLesionScore.TissuelesionsfromliverandheartwerescoredaccordingtoMellataetal.
2003.Thescoringscalefordifferentorganswasasfollows:iLiver:0=normal;1=slightamountsoffibrinousexudate;2=markedperihepatitis.iiHeartandpericardium:0=normal;1=vascularizationopacitycloudyfluidinthepericardialcavity;2=acutepericarditis.iiiLung:0=normal;1=edema;2=edemaandhyperaemia;3=edemahyperemiaandfibrininairsacs.ivSpleen:0=normal;1=swollen2=fibrinatedbedding.BacteriologicalExaminationsofTissuesQualitativeExamination.ThepresenceofthebacterialstrainusedforinfectionwasdeterminedqualitativelybystreakingthesamplesfromliverlungheartandspleendirectlyonMcConkeyagarplates.Theplateswereincubatedovernightat37°Cfor24handobservedforthepresenceofE.coli.BacterialRecoveryQuantitativeExamination.Liverheartlungandspleen100to200mgwerehomogenizedin1to2mLofPBSand100μLofserialdilutionsofthehomogenatewerespreadonMcConkeyagarplatesforbacterialquantification.Moreover1mLofthehomogenatewasincubatedovernightinLBbrothtoinvestigatethepresenceofE.coliinthetissuesamplesgivenabove.HematologyandClinicalBiochemistry.Hematologicalinvestigationswereperformedonheparinizedbloodsamplestakenfrombirdsduringeuthanization.ErythrocytecountsandPCVweremeasuredfollowingSwarupetal.1986whereasgranulocyteswerecountedusingeosinophilunopettemethodCampbell
1995.Forerythrocytecountsthebloodwasdiluted1:200inNattandHerrick1952solutionandforgranulocytecountitwasdiluted1:20inunopettesolutionwhichstainsonlyheterophilsandeosinophilsthenumberofcellswerecountedin9-mmareainaNeubauerchamber.Forclinicalbiochemistryplasmawasseparatedbycentrifugingbloodat3380×gfor15minandGOTLDHALPtotalproteinandalbuminweremeasuredonautomatedclinicalchemistryanalyzerHitachi911RocheDiagnosticsMannheimGermanywithreagenttestkitssuppliedbyRoche.GlobulinwasdeterminedasadifferencebetweentotalproteinandalbuminVarley
1975.HumoralImmuneResponse.AntibodiesagainstSRBCweremeasuredbyquantifyingtotalantibodytiterinadditiontomercaptoethanolsensitiveIgMandmercaptoethanolresistantIgGusingmicroagglutinationassayDelhantyandSolomon
1966.Briefly2-foldserialdilutionsofserumwerepreparedinPBSinmicrotiterplates;lateranequalvolumeof1%SRBCinPBSwasplacedinallwells.Plateswereshakenfor1minandincubatedfor1hat37°Cfortotalantibodytiter.Theagglutinationtiterwasexpressedaslog2ofthehighestdilutionofseragivingvisibleagglutination.ForIgGthetestwasperformedexactlyinthesamemannerexceptthattheplasmawasincubatedwithequalvolumeof
0.2Mof2-mercaptoethanolfor1hatroomtemperaturebeforemaking2-folddilutions.TheIgMwascalculatedasadifferenceoftotalimmunogloubinandIgGtiter.PrimaryantibodytiteragainstSRBCwasestimatedfromtheserumsamplescollectedafter10doffirstexposuretoSRBCwhereasthesecondaryantibodytiterwasestimatedfromtheseratakenatthedayofterminationoftheexperiment.Cell-MediatedImmuneResponse.ThePHAskintestforT-cell-mediatedimmunitywasconductedin41-d-oldchickensfollowingtheproceduresofGrasmanandScanlon1995usinga
0.1mLdoseof1mg/mLofPHAPSigmaSt.LouisMOinPBS.Featherswerepluckedfrombothwingwebs.OnewingwasinjectedwithPHAwhereastheotherreceivedaplaceboinjectionofPBSalone.Thethicknessofeachwingwebwasmeasuredtothenearest
0.05mmimmediatelybeforeand24±3haftertheinjectionsusingverniercaliperwiththeprecisionof
0.01mm.AstimulationindexwascalculatedasthechangeinthethicknessofthePHA-injectedwingwebminusthechangeinthicknessofthePBS-injectedwingweb.MicrobialPopulationsEnumerationFreshileacandcecalsamples
0.5gweredilutedwith
9.5mLofsterilizeddistilledwaterandvortexeduntilapHof
6.0wasobtained.Onegramofwetsamplewasdilutedwith10mLofdistilledwaterofwhich1mLwastransferredinto9mLofsterilizeddistilledwater.Sampleswereseriallydilutedfrom10−1to10−
7.One-tenthmilliliterofeachdilutedsamplewascoatedontheappropriatemediumforenumerationofmicrobialpopulations.BacterialcountswereperformedusingtheappropriatedilutionandplateculturetechniquesunderaerobicoranaerobicconditionsaccordingtoBarnesandImpey1970andtheresultswereexpressedascolony-formingunitslog10pergramoffreshsample.ThebacterialgroupsandspeciesdeterminedincludedlactobacilliLBSagarEscherichiacoliMac-Conkeyagarandbifidobacteriabifidobacteriumagarcomposedoftomatojuice400mL;dissolubleamylum
0.5g;peptone15g;yeastextract2g;glucose20g;sodiumchloride5g;Tween-801mL;5%cysteine
0.5mL;liverextract80mL;agarpowder20g;anddistilledwater520mL;pH=
7.0incubatedat37°Cfor72h.StatisticalAnalysisThedatawereanalyzedusing1-wayANOVAfollowedbyDuncan’smultiplerangetest.Fisher’sexacttestswereperformedtodeterminesignificantdifferencesbetweentheuntreatedandtreatedE.coli-challengedgroupsforisolationofEMB+E.colifromdifferentorgansandthepresenceofgrosslesions.Achi-squaredtestwasusedtoanalyzetheeffectofbacteriophageEC1onthemortalityofbirds.AllanalyseswereperformedusingSPSSsoftwareforWindowsversion13SPSSInc.ChicagoIL.AP-valueof
0.05wasconsideredstatisticallysignificant.StatisticalAnalysisAllresultswerepresentedasmeans.ExperimentaldatawereanalyzedusingtheSPSSforWindowsstatisticalpackageprogramversion
8.
0.0SPSSInc.ChicagoIL.ComparisonsofthemeanswereperformedusingDuncan’smultiplerangetest.SignificancewasdefinedasaP-valueof≤
0.05%.DiscussionYeastextractsupplementationsignificantlyimprovedboththeBWandthefeed:gainratioofthepoultschallengedwithE.coli.ImmunostimulationusingyeastextractsupplementsmayprotectpoultsfromyoungbreederflocksfromsomeoftheproductionlossduetocoldstressandE.coliinfectionbutmaysometimesbedetrimentaltobirdsnotneedingimmunostimulation.Animmune-mediatedpathologyduetoinflammationmayalsohaveledtothereportedincreaseinmortalityinMOS-supplementedpoultsthatwereorallychallengedwithE.coliFairchildetal.
2001.FairchildA.S.J.L.GrimesF.T.JonesM.J.WinelandF.W.EdensandA.E.Sefton.
2001.EffectsofhenageBio-MosandFlavomycinonpoultsusceptibilitytooralEscherichiacolichallenge.Poult.Sci.80:562–
571.Escalatingconsumerconcernsregardingpathogenresistancehaveplacedthepoultryindustryundermountingpressuretoeliminatetheuseofchemotherapeuticagentsasfeedadditives.Onepossiblealternativereceivingincreasedattentionistheuseofimmunomodulatorssuchasβ-glucan.Astudywasconductedtoinvestigatetheeffectsofayeast-derivedβ-glucanAuxofermYGTonbroilerchickperformancelesionscoresandimmune-relatedgeneexpressionduringamixedEimeriainfection.Day-oldchickswerefeddietscontaining
00.02or
0.1%YGT.Ond8posthatchone-halfofthereplicatepenswerechallengedwithamixedinoculumofEimeriaacervulinaEimeriamaximaandEimeriatenella.Measurementsweretakenandsamplescollectedond41014and21posthatch.Dietarysupplementationhadnoeffectonperformanceormortality.Ond143birdsperpenn=24/treatmentwerescoredforintestinalcoccidialesions.Grosslesionseveritywassignificantlyreducedinbirdssupplementedwith
0.1%YGT.Ond10induciblenitricoxidesynthaseiNOSexpressionwasdownregulatedinthejejunumofchallengedbirdsfed
0.1%YGT.ExpressionofiNOSintheileumwasdownregulatedinthenonchallengedbirdsbutupregulatedinthechallengedbirdsfed
0.1%YGTond
14.InterleukinIL-18wasupregulatedinthejejunumof
0.1%YGT-treatedbirds.InterferonIFN-expressionwasdecreasedinchallengedandnonchallengedbirdsfed
0.1%YGT.TheIL-4expressionwasdownregulatedinthenonchallengedbirdswith
0.1%YGTdietsupplementation.TheIL-13andmucin-1levelswerealsoreducedduetoβ-glucansupplementation.Mucin-2expressionwasincreasedinthenonchallengedbirdsbutdecreasedintheinfectedbirdsfed
0.1%YGT.TheseresultssuggestthatalthoughAuxofermYGTatdosesof
0.02and
0.1%doesnotinfluenceperformanceitsignificantlyreduceslesionseverityandiscapableofalteringimmune-relatedgeneexpressionprofilesfavoringanenhancedThelpertype-1cellresponseduringcoccidiosis.Immuneresponsestodietaryβ-glucaninbroilerchicksduringanEimeriachallengeC.M.Cox*L.H.Sumners*S.Kim*A.P.McElroy*M.R.BedfordandR.A.DalloulPoultSci
2010.89:2597-
2607.doi:
10.3382/ps.2010-00987Performanceandimmuneresponsestodietaryβ-glucaninbroilerchicksC.M.Cox*L.H.Stuard*S.Kim*A.P.McElroy*M.R.BedfordandR.A.Dalloul*1*AvianImmunobiologyLaboratoryDepartmentofAnimalandPoultrySciencesVirginiaTechBlacksburg24061;andABVistaFeedIngredientsMarlboroughWiltshireSN84ANUnitedKingdom1Correspondingauthor:RDalloul@vt.edumailto:RDalloul@vt.eduDuringthefirstweekposthatchtheavianimmunesystemisimmatureandinefficientatprotectingchicksfrominvadingpathogens.Amongimmunomodulatorsβ-glucansareknownasbiologicalresponsemodifiersduetotheirabilitytoactivatetheimmunesystem.Currentresearchsuggeststhatβ-glucansmayenhanceavianimmunity;howeververylittleisknownabouttheirinfluenceonregulationofimmunefunction.Astudywasperformedtoevaluatetheeffectsofdietaryβ-glucanongrowthperformanceimmuneorganweightsperipheralbloodcellprofilesandimmune-relatedgeneexpressionintheintestine.One-day-oldchickswerefedadietcontaining
00.02or
0.1%yeastβ-glucann=30/treatment.Ond7and14posthatchbodyandrelativeimmuneorganweightsweremeasuredandsmallintestinalsectionswerecollectedtoevaluategeneexpressionbyquantitativereal-timePCR.Peripheralbloodsampleswerealsocollectedtodetermineheterophil:lymphocyteratios.Supplementationofβ-glucandidnotsignificantlyaffectBWgainsandnosignificantdifferenceswereobservedamonggroupsforrelativeimmuneorganweightsorheterophil:lymphocyteratios.ComparedwithcontrolsexpressionofinterleukinIL-8wasdownregulatedintheβ-glucan-treatedgroupsond7and
14.Ond14β-glucaninclusionresultedinincreasedinduciblenitricoxidesynthaseexpression.ExpressionofIL-18wasupregulatedond7butreducedond14duetoβ-glucansupplementation.Ond7interferon-andIL-4expressiondecreasedintheβ-glucan-treatedgroups.Howeverond14IL-4expressionwasupregulatedinthesupplementedgroups.IntestinalexpressionofIL-13wasalsodownregulatedintheβ-glucan-treatedbirdsond
7.Theseresultssuggestthatdietaryinclusionofβ-glucansalteredthecytokine-chemokinebalance;howeveritdidnotelicitarobustimmuneresponseintheabsenceofachallengeresultinginnodeleteriouseffectsonperformance.KeyWords:β-glucan•broiler•cytokine•immunityPoultSci
2010.89:1924-
1933.EfficacyofabacteriophageisolatedfromchickensasatherapeuticagentforcolibacillosisinbroilerchickensG.L.Lau*C.C.Sieo*1W.S.Tan*M.Hair-BejoA.JalilaandY.W.Ho*DepartmentofMicrobiologyFacultyofBiotechnologyandBiomolecularSciencesInstituteofBioscienceDepartmentofVeterinaryPathologyandMicrobiologyFacultyofVeterinaryMedicineandDepartmentofVeterinaryClinicalStudiesFacultyofVeterinaryMedicineUniversitiPutraMalaysia43400UPMSerdangSelangorMalaysia1Correspondingauthor:ccsieo@biotech.upm.edu.mymailto:ccsieo@biotech.upm.edu.myTheefficacyofbacteriophageEC1alyticbacteriophageagainstEscherichiacoliO78:K80whichcausescolibacillosisinpoultrywasdeterminedinthepresentstudy.Atotalof480one-day-oldbirdswererandomlyassignedto4treatmentsgroupseachwith4pensof30birds.BirdsfromthecontrolgroupsgroupsIandIIreceivedPBSpH
7.4or1010pfuofbacteriophageEC1respectively.GroupIIIconsistedofbirdschallengedwith108cfuofE.coliO78:K80andtreatedwith1010pfuofbacteriophageEC1at2hpostinfectionwhereasbirdsfromgroupIVwerechallengedwith108cfuofE.coliO78:K80only.Allthematerialswereintroducedintothebirdsbyintratrachealinoculation.BasedontheresultsofthepresentstudytheinfectionwasfoundtobelesssevereinthetreatedE.coli-challengedgroup.MeantotalviablecellcountsofE.coliidentifiedoneosinmethyleneblueagardesignatedEMB+E.coliinthelungsweresignificantlylowerintreatedE.coli-challengedbirdsthaninuntreatedE.coli-challengedbirdsond1and2postinfection.TheEMB+E.coliisolationfrequencywasalsolowerintreatedbirds;noE.coliwasdetectableinbloodsamplesonanysamplingdayandE.coliwereisolatedonlyintheliverheartandspleenoftreatedchickensataratioof2/61/6and3/6respectivelyatd1postinfection.TheBWofbirdsfromtheE.coli-challengedgrouptreatedwithbacteriophageEC1werenotsignificantlydifferentfromthoseofbirdsfrombothcontrolgroupsbutwere
15.4%higherthanthoseoftheuntreatedE.coli-challengedgroupond21postinfection.Thetotalmortalityrateofbirdsduringthe3-wkexperimentalperioddecreasedfrom
83.3%intheuntreatedE.coli-challengedbirdsgroupIVto
13.3%inbirdstreatedwithbacteriophageEC1groupIII.TheseresultssuggestthatbacteriophageEC1iseffectiveinvivoandcouldbeusedtotreatcolibacillosisinchickens.KeyWords:bacteriophage•Escherichiacoli•colibacillosis•broilerPoultSci
2010.89:2589-2596Bacterialclearanceheterophilfunctionandhematologicalparametersoftransport-stressedturkeypoultssupplementedwithdietaryyeastextract1G.R.Huff*2W.E.Huff*M.B.FarnellN.C.Rath*F.SolisdelosSantosandA.M.Donoghue**USDAAgriculturalResearchServicePoultryProductionandProductSafetyResearchUnitFayettevilleAR72701;PoultryScienceDepartmentTexasAMUniversityCollegeStation77843;andAnimalScienceDepartmentInstitutoSuperiordeAgriculturaISAApartadoPostal166SantiagoDominicanRepublic2Correspondingauthor:grhuff@uark.edumailto:grhuff@uark.eduYeastextractsYEcontainbiologicalresponsemodifiersthatmaybeusefulasalternativestoantibioticsforcontrollingpathogensinpoultryproductionandmitigatingthedeleteriouseffectsofproductionstressors.TheobjectiveofthepresentstudywastodeterminetheabilityofacommercialdietaryYEAlphamunetomodulatetheimmuneresponseinmaleturkeypoultschallengedwithEscherichiacoliandsubjectedtotransportstress.Alphamunewasaddedtoturkeypoultdietsat0500or1000g/ton.Poultswerechallengedbyairsacinjectionwith60cfuofE.coliat1wkofage.At3wkofagethesechallengedbirdsweresubjectedtotransportstressandbirdswerebledandnecropsiedthefollowingmorning.Bloodcellnumbersandpercentageshematologicalparametersandclinicalchemistryvaluesweredetermined.Oxidativeburstactivityofisolatedheterophilswasmeasuredusingstimulationwithphorbolmyristateacetateanda27-dichlorofluoresceindiacetateassay.DatawereanalyzedusingGLMandleastsquaresmeansproceduresoftheSASprogram.ThenumbersandpercentagesofheterophilsinperipheralbloodwereincreasedandtheiroxidativeburstactivitywasstimulatedbyYE.ThestresschallengedramaticallyincreasedoxidativeburstandthisincreasewassignificantlymodulatedbyYEtreatment.SerumlevelsofcalciumphosphorusandtriglyceridesweredecreasedanduricacidlevelserythrocytenumbershemoglobinandhematocritwereincreasedbyYEsupplementation.BacteriawereisolatedfromtheairsacandliverofalowerpercentageofbirdsprovidedwithYE.TheseresultssuggestthatdietaryYEhaspotentialasanonantibioticalternativefordecreasingbacterialpathogensinturkeyproduction.KeyWords:turkey•yeastextract•Escherichiacoli•transportstress•heterophil1MentionofatradenameproprietaryproductorspecificequipmentdoesnotconstituteaguaranteeorwarrantybytheUSDAanddoesnotimplyitsapprovaltotheexclusionofotherproductsthatmaybesuitable.PoultSci
2010.89:447-
456.DifferentialspleniccytokineresponsestodietaryimmunemodulationbydiversechickenlinesS.B.Redmond*R.M.TellD.Coble*C.Mueller*D.PaliC.B.AndreasenandS.J.Lamont*1*DepartmentofAnimalScienceDepartmentofBiomedicalScienceandDepartmentofVeterinaryPathologyIowaStateUniversityAmes500111Correspondingauthor:sjlamont@iastate.edumailto:sjlamont@iastate.eduNutritionalmodulationoftheimmunesystemisanoftenexploitedbutpoorlycharacterizedprocess.Inchickensandotherfoodproductionanimalsdietaryenhancementoftheimmuneresponseisanattractivealternativetoantimicrobialuse.Ayeastcellwallcomponentβ-13/16-glucanaugmentstheresponsetodiseaseinpoultryandotherspecies;howeverthemechanismofactionisnotclear.Ascorbicacidandcorticosteronearebettercharacterizedimmunomodulators.Inchickensthespleenactsbothasreservoirandactivationsiteforleukocytesandthereforesplenicgeneexpressionreflectssystemicimmunefunction.TodetermineeffectsofgeneticlineanddietaryimmunomodulatorschickensofoutbredbroilerandinbredLeghornandFayoumilineswerefedeitherabasaldietoranexperimentaldietcontainingβ-glucansascorbicacidorcorticosteronefrom56to77dofage.SpleenswereharvestedmRNAwasisolatedandexpressionofinterleukinIL-4IL-6IL-18macrophageinflammatoryprotein-1βinterferon-andphosphoinositide3-kinasep110transcriptswasmeasuredbyquantitativereversetranscriptionPCR.Effectsofdietgeneticlinesexanddietxgeneticlineinteractiononweightgainandgeneexpressionwereanalyzed.At12and3wkafterstartingthediettreatmentsbirdsfedthecorticosteronediethadgainedlessweightcomparedwithbirdsfedtheotherdietsP
0.
001.SexaffectedexpressionofIL-18P=
0.010withhigherlevelsinmales.TherewasasignificantinteractionbetweengeneticlineanddietonexpressionofIL-4IL-6andIL-18P=
0.
0210.006and
0.026respectively.Broilerlinegeneexpressiondidnotchangeinresponsetotheexperimentaldiet.SplenicexpressionofIL-6washigherinLeghornsfedthebasalorascorbicaciddietsratherthantheβ-glucanorcorticosteronedietswhereastheoppositerelationshipwasobservedintheFayoumiline.ExpressionofIL-4andIL-18respondedtodietonlywithintheFayoumiline.Thedifferentialsplenicexpressionofbirdsfromdiversegeneticlinesinresponsetonutritionalimmunomodulationemphasizestheneedforfurtherstudyofthisprocess.KeyWords:dietaryimmunomodulation•spleen•cytokinePoultSci
2010.89:1635-
1641.MaterialsandMethods。