溶組織內阿米巴課件Tobedefinedasunicellularanimals；Thesinglecellrelativelyhascomplexmetabolicactivitiessuchasdigestion,reproduction,respiration,excretion,etc.10,000speciesofparasiticprotozoa.Importanthumanparasiticprotozoa:Malariaparasites,Leishmania,Entamoebahistolytica,Trichomonasvaginalis,TrypanosomaandToxoplasmagondiiProtozoa：Morphology1、diversity:round,ellipse,pearshape,irregular

2、Size：

verysmallRangeinsizefrom2tomorethan200μm1.Plasmamembrane:2.Cytoplasm3.NucleiStructure1.Plasmamembrane:2.Cytoplasm3.Nuclei1.Plasmamembrane:aunitmembraneStructure1.Plasmamembrane:2.Cytoplasm3.Nuclei2.Cytoplasmectoplasm:theoutertransparentlayer.

function:protection,locomotion,sensation.2)endoplasm:theinnergranularlayer,containingvacuolesandorganelles.

function:metabolism,nutrition,reproduction.3)organelles:1.Plasmamembrane:2.Cytoplasm3.Nuclei2.Cytoplasm3)organelles:

A.membraneorganelles:Mitochondria,Endoplasmicreticulum,Golgibodies,etc.B.locomotororganelles:pseudopodia,flagella,cilia.Structure1.Plasmamembrane:2.Cytoplasm3.Nuclei3.Nucleicompactnucleus：seldom2)vesicularnucleus：commonNuclearmembraneAkaryosomeChromatingranulesStructurePhysiologyLocomotion:Nutrition:Reproduction:Metabolism:Excretion:Locomotion:Nutrition:Reproduction:Metabolism:Excretion:Locomotion:

1)flagella,2)cilia,3)pseudopodia,4)andnospecificlocomotionorganelles.TrichomonasvaginalisPhysiologyLocomotion:Nutrition:Reproduction:Metabolism:Excretion:Locomotion:1)flagella,2)cilia,3)pseudopodia,4)andnospecificlocomotionorganelles.BalantidiumcoliPhysiologyLocomotion:Nutrition:Reproduction:Metabolism:Excretion:Locomotion:1)flagella,2)cilia,3)pseudopodia,4)andnospecificlocomotionorganelles.EntamoebahistolyticaPhysiologyLocomotion:Nutrition:Reproduction:Metabolism:Excretion:Locomotion:1)flagella,2)cilia,3)pseudopodia,4)andnospecificlocomotionorganelles.plasmodiumPhysiologyLocomotion:Nutrition:Reproduction:Metabolism:Excretion:2.Nutrition

1)permeation:

bydiffusionorbyactivetransport

2)pinocytosisandphagocytosis:

PhysiologyLocomotion:Nutrition:Reproduction:Metabolism:Excretion:3.Reproduction

1)asexualreproduction2)sexualreproductionPhysiologyPhysiologyLocomotion:Nutrition:Reproduction:Metabolism:Excretion:3.Reproduction1)asexualreproduction①binaryfission:②multiplefission:③buddingreproduction:PhysiologyLocomotion:Nutrition:Reproduction:Metabolism:Excretion:3.Reproduction1)asexualreproduction2)sexualreproduction

①gametogony:②conjugation:zygoteClassificationofprotozoaclasslocomotoryorganellesreproductionspeciesnameZoomastigophoraflagellabinaryfissionTrichomonasvaginalis

LoboseapseudopodiabinaryfissionEntamoebahistolytica

Sporozoeanospecificlocomotionmultiplefission,gametogonyPlasmodiumvivax

Kinetofrag-Minophoreaciliabinaryfission,syngamyBalantidiumcoli

Entamoebahistolytica

E.histolyticaliveswithinthelargeintestine.Trophozoitescaninvadethecolonicepitheliumandproduceulcersanddysentery.Thisinvasivediseasecanbecomeprogressivelyworseandleadtoextraintestinalamebiasis.MalariaSchistosomiasisAmoebiasisPrevalenceofamoebiasis400million200million50millionMorphology1.Trophozoite

pseudopodiumnucleuserythrocyteChromaticgranuleskaryosomeAchromaticfibrilsTrophozoitepicturebyscanningelectronmicroscope2.CystStainedbyIronhematoxylinchromatoidbodyglycogenvacuole2.CystStainedbyIodineMaturecyststrophozoitestrophozoitescystLifecycleBeingestedBepassedintheformedstoolInthelowersmallintestine,excystationInthelowercolonInvadethecolonicwalltrophozoitestrophozoites

trophozoitesBepassedinthedysentericfecesGointothecirculatorysystem,andspreadtoliver,lung,brain,etctrophozoitestrophozoitesSummaryoflifecycleInfectivestage:maturecyst.Infectionoccursbytheingestionofcystsincontaminatedwater,food,orbythefecal-oralroute(handsorfomites).Cystsareseenintheformedstool.Trophozoitesareseeninthedysentericfecesandliver,lung,brain,etcPathogenesisandManifestation.~10%infectedwithE.histolyticawilldevelopinvasiveamebiasis.?Factorsthatdetermineinvasionofamebas:1.ParasitefactorsAThenumberofamebasingested.BThepathogeniccapacityoftheparasitestrain2.Hostfactors3.BacteriafactorsPossiblepathogenicmechanismPossiblepathogenicmechanismparasitefactors1resistancetohostresponse(eg,complementresistance)①toresistancetocomplementmediatedlysis②todegradesecretoryIgA③tosuppressT-cellresponses④tokillneutrophilsandotherimmuneeffectorcellsinacontactdependentmanner.(lysisofneutrophilscouldreleasetoxicproductswhichcontributetothedestructionofhosttissue)PossiblepathogenicmechanismAdherencepropertiesmediatedbysurfacelectinknownasGal/GalNAC(半乳糖/乙酰氨基半乳糖凝集素)3Cytolyticproperties(adherence+'amoebapore')4Secretecytotoxins(cysteineproteinases)andkilltargetcellintheintestinalmucosaparasitefactors:

Hostfactors

PossiblepathogenicmechanismHostfactorsinamoebiasismaybenon-immunedefensemechanismandspecificimmunity.Suitableentericbacteriacanenhanceamebicgrowth.BacteriafactorsAnexperimentwithcatsGroupAGroupBMaturecystsMaturecysts+BacillusaerogenesLowermorbilityHighermorbilityGentlesymptomSerioussymptomnon-invasive.amebacolonyonmucosasurface.asymptomaticcystpasser.non-dysentericdiarrheaAmebiasisProgressioninvasive

.necrosisofmucosa→ulcer.dysentery.hematophagoustrophozoitesMucuslayerMusclelayerSerouslayerSubmucosalumen.ulcerenlargement→peritonitis.occasionalameboma.metastasis→extraintestinalamebiasismetastasis→extraintestinalamebiasis.viablood-streamordirectextension.primarilyliver→amebicabscess.othersitesinfrequent.ameba-freestoolscommonAmebiasisProgressionAmebiasisProgressioninvasivepathogenesis

&manifestation.ulcerenlargement→peritonitis.occasionalameboma.necrosisofmucosa→ulcer.dysentery.hematophagoustrophozoitesTheplacesthatamebiculcersoccurusuallyCaecum87%Ascendingcolon57%Sigmoidcolon33%Rectum37%Pathogenesis.metastasis→extraintestinalamebiasis.viablood-streamordirectextension.primarilyliver→amebicabscess.othersitesinfrequent.ameba-freestoolscommonAmebicliverabscessLaboratorydiagnosis.Stoolexamination.Sigmoidoscopy.Immunologicaldiagnosis.Imaging.Abscessaspiration①FormedstoolsAdirectsmearstainedbyIodine/Ironhematoxylinforcyst.Compare:Laboratorydiagnosis.Stoolexamination①FormedstoolsAdirectsmearstainedbyIodine/Ironhematoxylinforcyst.②diarrheicstoolsAdirectsalinesmearformotiletrophozoites.1)freshstools2)intime3)keepwarmincoldweatherLaboratorydiagnosis.Stoolexamination.SigmoidoscopyLesions,aspirate,biopsyLaboratorydiagnosis.Stoolexamination.Sigmoidoscopy.Immunologicaldiagnosis①Fluorescentantibody②Theindirecthemagglutinationtest③IndirectfluorescentantibodytestLaboratorydiagnosis.Stoolexamination.Sigmoidoscopy.Immunologicaldiagnosis.ImagingCT,MRI,ultrasound,X-rayLaboratorydiagnosis.Stoolexamination.Sigmoidoscopy.Immunologicaldiagnosis.Imaging.AbscessaspirationOnlyselectcasesEpidemiology

Distributionallpopulationsthroughouttheworld.thetropicsandsubtropicathanincoolerclimates.insanitarycommunitiesoftemperateandsubarcticareasEpidemiology

DistributionTheincidence

is

estimatedthatupto10%oftheworld'spopulationmaybeinfectedwitheitherE.histolyticaorE.disparandinmanytropicalcountriestheprevalencemayapproach50%.Thereareanestimated50millioncasesofamebiasisperyearandup50to100thousanddeathsamongthem.

Epidemiology

EpidemicfactorsReservoirofinfection:asymptomaticoronlymildlyafflicted.

Thecystsarerelativelyresistanttobadconditionofenvironment.Disposalofhumanfecesisinadequate,andleadtocontaminationoffoodorwaterwithfecalmaterial.Thehouseflyandthecockroachisan

importancefactorinthetransmissionofthedisease.ProphylaxisandTreatmentAmebiasistreatment:

Asymptomatic:Iodoquinol,Paromomycin,orDiloxanidefuroate

Nondysenteric,Dysenteric,orExtraintestinal:Metronidazole(甲硝唑,滅滴靈),orTinidazole+lumenalagentProphylaxisandTreatmentAmebiasistreatment:2.Sanitarydisposaloffeces.3.Protectingwatersuppliesfromcontamination.4.Healtheducationinregardtoimprovingpersonalhygiene,drinkingboiledwater,handwashing5.Killingthehouseflyandthecockroach.Entamoebadispar

E.histolyticaandE.disparareactuallytwomorphologicallyidenticalspecies.(E.histolyticaandE.disparcannotbedistinguishedonmorphologicalcriteria,butDNAsequenceandisoenzymepattern.)

E.disparisnon-pathogenic.(E.histolyticaispathogenic.)Tocausehumandisease:.Primaryamebicmeningoencephalitis(PAM).Chronicgranulomatousamebicencephalitis(GAE).Amebickeratitis

Pathogenicfree-livingamebae

NaegleriaAcanthamoeba

Pathogenicfree-livingamebaeNaegleriaTheportalofentry:thetrophozoitesenterthenasalcavity,replicating,andthenmigratealongtheolfactorynervesintothebrainandCNS.

Pathogenicfree-livingamebaeAcanthamoebaTheportalofentry:unknownbutbelievedtotheeitherthelungs,skinoreyes.Presumablythetrophozoitesdisseminatebyahematogenousroute.

Pathogenicfree-livingamebaeEntamoebaEntamoebahistolyticaEntamoebacoliEntamoebadisparNaegleriaAcanthamoebasummaryMaturecy