課件-12級(jí)4章、細(xì)菌感染與免疫

Chapter4BacterialInfectionandImmunityInfection

Bacteriabreakthroughdefencemechanismofhost,growinvivo,andproducevarioustoxicsubstances.Atlast,Itcancausevaryingdegreespathologicalchanges.

Basedonthisconcept,bacteriacanbeclassifiedinto3majorgroups:truepathogens,opportunisticpathogensandnon-pathogens.

Normalfloraandopportunisticpathogens

BacterialpathogenesisOccuranddevelopmentofinfectionAnti-bacteriaimmunityHospitalacquiredinfectionNormalfloralandopportunisticpathogen1.Concept:--resideontheskinandmucousmembranesofhealthynormalpersons--canplayadefiniteroleinmaintaininghealthandnormalfunctionwhenimmunityofthehostisnormalI.NormalfloraNormalfloraOfIntestinaltract2.Classification:

ResidentfloraTransientflora3.Distribution:SkinRespiratorytractIntestinaltractGenitourinarytractNormalfloraofbody乳桿菌、大腸桿菌、類白喉?xiàng)U菌、白念珠菌等陰道白色葡萄球菌、類白喉?xiàng)U菌、非致病性分枝桿菌等尿道大腸桿菌產(chǎn)氣桿菌、變形桿菌、綠膿桿菌、葡萄球菌、糞鏈球菌、類桿菌、產(chǎn)氣莢膜梭菌、破傷風(fēng)梭菌、雙歧桿菌、真細(xì)菌、乳桿菌、白念珠菌等腸道一般無菌胃白色葡萄球菌、干燥桿菌等外耳道葡萄球菌、類自喉?xiàng)U菌、綠膿桿菌、非致病性分枝桿菌等眼結(jié)膜葡萄球菌、甲型和丙型鏈球菌、肺炎球菌、奈瑟菌、乳桿菌等鼻咽表皮葡萄球菌、甲型和丙型鏈球菌、肺炎球菌、奈瑟菌、類桿菌、梭桿菌等口腔葡萄球菌、類自喉?xiàng)U菌、綠膿桿菌、非致病性分枝桿菌、丙酸桿菌、白念珠菌等皮膚主要菌類部位

眼結(jié)膜白色葡萄球菌、干燥桿菌人體內(nèi)正常菌群的分布

陰道

大腸桿菌、乳桿菌白念珠菌、類白喉?xiàng)U菌、非致病性分枝等

外耳道葡萄球菌、類白喉?xiàng)U菌綠膿桿菌、非致病性分枝桿菌

鼻咽腔葡萄球菌、甲，丙型鏈球菌肺炎球菌、奈氏菌、類桿菌等表皮葡萄球菌口腔甲，丙型鏈球菌類白喉?xiàng)U菌、肺炎球菌奈氏菌、乳桿菌、梭桿菌螺旋體、放線菌、白念珠菌

皮膚葡萄球菌、綠膿桿菌、白念珠菌丙酸桿菌、類白喉?xiàng)U菌、非致病性分枝桿菌

尿道白色葡萄球菌、類白喉?xiàng)U菌、非致病性分枝桿菌

腸道大腸桿菌、產(chǎn)氣桿菌、變形桿菌綠膿桿菌、葡萄球菌、厭氧性細(xì)菌真菌、乳桿菌，雙歧桿菌等4.Physiologicfunctions

:1)BiologicAntagonismFunctionBiologicbarriersChemicalbarriersCompetitionfornutrients

2)NutritionalFunctionSynthesizevitaminKandvitaminBAidintheadsorptionofnutrients

3)ImmuneFunctionPromotedevelopmentofimmuneorganEnhancethehost’simmuneresponseActivatemacrophageandincreasethereleasingofcytokines4)ExpellingoftoxinFunctionLowerG-bacteriainintestinaltractandreducereleaseofendotoxinProduceacidicmaterialandmakeforexpellingoftoxin.ProduceSOD5)Anti-agingFunction6)Anti-tumorFunctionDegradepro-carcinogensinIntestinaltractEnhancephagocyticactivityofphagocyte1.Concept:II.OpportunisticpathogenNormalbacteriaandlatent潛在的pathogenfrombody;Non-pathogenandlatentpathogenfromenvironmentInfectioncausedbyopportunisticpathogenisopportunisticinfection2.Infectionconditions:1)Immunityofhostgettingweak2)Translocation3)DysbacteriosisandsuperinfectionMicroeubiosisMicrodysbiosis生態(tài)失調(diào)MicroecologicaladjustmentIII.Microecology微生態(tài)學(xué)BacterialpathogenesisPathogenicity

Pathogenicityistheabilityofamicro-organismtocauseinfectionanddiseaseinaHost.BacteriaHostpathogenicityimmunityVirulenceInvasivenessToxinLD50orID50NumberofinfectionbacterialPortalentryBacterialvirulencefactors1.Invasiveness

ordinarypili

capsule,microcapsuleorLTAVirulence1-1Adhesionand定植Colonization

Adhesin

VariousmechanismPossessaltitudinalspecificityAdhesinistobeligand;Proteinandglycoproteinincellsurfaceistobereceptor.

Adhesionmechanism

Microcolony小菌落；小集落Biofilm生物膜Adhesion

ResultsFirstdayThirddayDaysix

BiofilmP.aeruginosaC.albicans

生物醫(yī)學(xué)材料相關(guān)感染：人工心臟瓣膜、人工關(guān)節(jié)、動(dòng)靜脈導(dǎo)管、氣管插管等。

慢性頑固性感染疾?。郝苑杭?xì)支氣管炎、囊性纖維化、SBE、慢性骨髓炎、褥瘡等。InfectionwithBiofilmrecurrentIntractablepersistenceCharacteristicofBiofilminfection

1-2Invasionofhostcells&tissuesInvasinInvasiveenzymesuchasHyaluronidase

1-3ImmuneescapeAnti-phagocytosisanddigestioncapsule,microcapsuleorCoagulasepletephagocytosisProduceIgAproteaseAntigenvariationInterferenceactivityofcomplement2.Toxin2-1ExotoxinOrigin

--ProducedmainlybyG+(includeafewG-)--Liberatedfromlivingbacterialcell

Nature

--virulentProteinCharacter

HighlytoxigenicityHighlyselectivityHighlyantigenicity

and

canproduceantitoxinDetoxificationtoxoidType

Onebacterialstraincanproducevariousexotoxin,butonlyoneorsomeexotoxinaremaininoneinfection.

Basedonitsmodeofactionandaffinitytotissue,exotoxincanbeclassifiedinto3majorgroups:Neurotoxin,CytotoxinandEnterotoxin

Neurotoxin

Actonnervoustissueandcauseabnormalofneurotransmission

Cytotoxin

Includesuppresssynthesisofproteinanddamagecellmembrane.

Enterotoxin

Actonenterocyteandcauseabnormalofbowelfunction.Moleculestructure

TypeA-BtoxinActiveBindingACellsurfaceB

single-chaintoxinVirulencegene

PlasmidTransposonTemperatebacteriophageChromosomeDNAPathogenicityisland2-1EndotoxinOriginNature--ProducedbyG---Liberatedfromcellwallofdeadbacteria--LPS(Lipopolysaccharide)StructureofLPSlipidACorepolysaccharidespecificpolysaccharideWeaktoxigenicityNoselectivityPoorantigenCannotetotoxoid

CharacterMechanismofactionFormofLPS-LBP-CD14complexInteractionbetweenLPS-LBP-CD14andTLR4,MD-2TriggercascadereactionofsignaltransductionReleaseofTNF-α,

IL-1,IL-6,IL-8etc.Produceofinflammatoryfactor

,bioactivemedium,acutephaseproteinetc.FeverleukocytosisorLeukopeniaEndotoxemiaandshockDisseminatedintravascularcoagulation(DIC)Immunregular

BiologicalactivitiesNumberofbacterialentry

NumberofbacteriaandvirulencepresentInverseproportionPortalentrySimplepathwayMulti-pathwayOccurandDevelopmentofinfection1.SourceofInfectionExogenousinfection:patient,carrier,diseasedanimaloranimalcarrier.Endogenousinfection

:mostarenormalflora,causeinfectionunderabnormalcondition.2.Transmission

ofInfection

VerticaltransmissionHorizontaltransmissionSkinRespiratorytractDigestivetractUrogenitaltractMorethanoneroute3.TypeofInfectionAccordingtoresultInapparentor亞臨床的subclinicalinfectionApparentinfection:causeapparentclinicsyndromeCarrierstate:carrierAcuteinfectionChronicinfectionSubacuteinfectionAccordingtodegreeofurgencyAccordingtopositionandnatureLocalinfectionGeneralizedorsystemicinfectionToxemia--isthepresenceofexotoxinsintheblood.Endotoxemia--isthepresenceofendotoxinsintheblood.Bacteremia--isaninvasionofthebloodstreambybacteria.Septicemia

--illnessthatoccurswhenpoisonoussubstancesproducedbycertainbacteriaenterthebloodstream.Pyemia

--iscausedbypyogenicbacteriaintheblood.GeneralizedorsystemicinfectionAnti-BacteriaImmunityComponentsoftheImmuneSystemHumoralCellularHumoralCellularSpecificNonspecificcomplement,interferon,TNFetc.macrophages,neutrophilsTcells;othereffectorscellsantibodiesBalancebetweenInfectionandImmunityinfectionimmunityBolusofinfectionxvirulenceimmunityDisease=ResponsetoInfectioninfectionxdiseaseInnateimmunitynodiseaserecoveryadaptiveimmunityre-infectionnodiseasexInnateImmunityAdaptiveImmunityComponents

ofInnateandAdaptiveImmunityskin,blood-brain,blood-placentaLysozyme,antibacteroalpeptide,Complement,cellfactor,ectmacrophage,NKcellNeutrophilphysicalbarrierssolublefactorscellsnoneImmunoglobulins(antibody)TandBlymphocytesPhagocytosisMigrationRecognitionPatternrecognitionreceptor(PRR)--TLR,LPS-RPathogen-associatedmolecularpattern(PAMP)IngestionKilling細(xì)胞核Chemotacticresponsetoinflammatorystimulus

MacrophageAttackingE.coli(SEMx8,800)BactericidalMechanismOxygen-dependentbactericidalsystem--O2-,H2O2sterilizedirectly--1O2,OH-damageDNA,lipid,protein--MPOandHalogendamageproteinNitrogen-dependentbactericidalsystem--NOOxygen-no-dependentbactericidalsystem--lysozyme,Defensin,Proteolyticenzyme,Nuclease,ectResultofPhagocytosisCompletephagocytosis

pletephagocytosisDemagetissueandcell內(nèi)毒素被解毒醋酶血清內(nèi)毒素解毒因子多種細(xì)菌肽蛋白質(zhì)血清正常調(diào)理素革蘭陽性菌蛋白質(zhì)乳汁乳素革蘭陽性菌堿性多肽膜、腎、前列腺精素、精膠堿需鐵細(xì)菌假球蛋白血清轉(zhuǎn)鐵蛋白革蘭陽性菌含鐵葉琳紅細(xì)胞正鐵血紅素革蘭陽性菌堿性多肽血小板血小板素革蘭陽性菌堿性多肽中性粒細(xì)胞白細(xì)胞素革蘭陰性菌堿性多淋巴系統(tǒng)組蛋白多種細(xì)菌堿性多肽中性粒細(xì)胞吞噬細(xì)胞殺菌素革蘭陽性菌血清乙型溶素革蘭陽性菌堿性多肽吞噬細(xì)胞榕酶體、唾液、淚液、乳汁等溶菌酶正常球蛋白血清補(bǔ)體作用對(duì)象化學(xué)性質(zhì)主要來源抗菌物質(zhì)正常體液與組織中的抗菌物質(zhì)AdaptiveImmunityMucosalimmunity

--Tonsil,Payer’spatches,Epityphlon--MicrofoldcellHumoral體液immunityCellularimmunityInnateImmunityAdaptiveImmunityCharacteristics

ofInnateandAdaptiveImmunityNoImmunologicmemoryAntigenindependentNotimelagNotantigenspecificAntigendependentAlagperiodAntigenspecificDevelopmentofmemory

Typeofinfection

Typeofimmunity

Extracellularbacteria

Antibody-mediatedPhagocyte;Complement

Exotoxins

Antitoxins;SIgA

Intracellularbacteria

T

cell-mediatedimmunity

CharacteristicsofAnti-

bacteriaImmunityHospitalacquiredinfectionIt(ial醫(yī)院內(nèi)infection)referstoinfectionamonggroupsofpeoplewhentheyaccepteddiagnose,treatment,andnursingwi