微生物学 Chapter23.24 呼吸道病毒、胃肠道病毒

Chapter23Respiratoryviruses呼吸道病毒Inacuteinfectionofrespiratorytract,90%-95%ofcasesarecausedbyviruses.CategoriesofRespiratoryVirusesOrthomyxoviridae:

InfluenzavirusParamyxoviridae:

Parainfluenzavirus;Mumpsvirus;Measles;RespiratorysyncytialvirusTogaviridae:

RubellaVirusCoronaviridae:

CoronaVirus;SARSvirusAdenoviridae:

humanAdenovirus

picornaviridae:

RhinoVirus;Reoviridae:

reovirusSection1

InfluenzavirusInfluenzaAvirusescaninfectavarietyofdifferentspeciesandcancauseworldwideepidemicsofinfluenza.InfluenzaBviruses

infectshumansandcancausemajoroutbreaksofinfluenza.InfluenzaCviruses

mainlyinfectshumansandcancausemildrespiratorytractinfections,butdoesnotcauseoutbreaksofinfluenza.Ⅰ.Biologicalproperties

Spherical,100-120nmindiameter,enveloped,spikes

1)core:

-ssRNA,segmented(7-8pieces)

2)NP:surroundandbindtheRNA,type-specific,stable.

3)envelope:

M1、M2、lipidbilayermembrane

4)spikes：HA、NA1.MorphologyandstructureM1proteinhelicalnucleocapsid(RNAplusNPprotein)HA-hemagglutininpolymerasecomplexlipidbilayermembraneNA-neuraminidaseInfluenzavirusHemagglutinin(HA)2

units:HA1

andHA2*agglutinatehumanandsomeanimalRBC*berelatedtotheadsorptionofviruses(receptor:sialicacid)*antigenicity:showgreatvariability

AbstotheHAareprotective,neutralizeviralinfectivity.Neuraminidase(NA)

*berelatedtothereleaseofviruses:hydrolyzetheterminalneuraminicacidofglycoproteinonsurfaceofcells.

*antigenicity:variable2.TypeandvariationBasedonantigenicityofNPandM1:----InfluenzaA,B,C.

BasedonHA,NA:

InfluenzaAsubtype;eg:H1N1BasedonHA(16),NA(9):subtype

A/HongKong/1/68(H3N2)typeA,B,C:NP,M1proteinsub-types:HAorNAproteinAntigenicshift:whicharemajorchangesbasedontheaccumulationofmutationsorreassortmentofsegmentsofthegenomeRNA.ItcanresultinanewinfluenzaAsubtypeandusuallycauselargescaleepidemicofinfluenza.

Antigenicdrift:whichareminorchangesbasedonpointmutationinthegenomeRNA.ItcannotresultinanewinfluenzaAsubtypeandusuallycausemedianorsmallepidemicofinfluenza.Antigenicshift3.Cultivation

Cultureinchickenembryo.Cultureincellculture(non-CPE)4.Resistance

Inactivated56℃30min.

Ⅱ.PathogenesisandimmunitySpreadviarespiratorydroplets.virusparticlesbindstocellsoftherespiratoryepithelium

Clinicalfeatures:

*respiratorytractsymptoms:sorethroat,coughetc;*systemicsymptoms:headache,fever,myalgias(musclepains).Emergencyhospitalduring1918influenzaepidemic1819Ⅲ.MicrobiologicaldetectionVirusIsolationRapidDiagnosis:detectvirusantigenornucleicacid

Serology:HI(hemaggultinationinhibition)Ⅳ.PreventionandtreatmentVaccine:

Wholeinactivatedvirusvaccines----includingH1N1,H3N2andaBsubtype.Treatment:

Rimantadine(金刚乙胺)

Amantadine(金刚烷胺)

Oseltamivir(达菲)

SectionⅡAvianInfluenzavirusBelongtotypeAinfluenzaviruses;Caninfectbirds,pigs,horses,sealsandwhales,etc;Avianinfluenzainfectionsinhumans:

1997:HongKong,(H5N1)1999:HongKong,H9N22003:HongKong,H5N12003:Netherlands,H7N72006:America,H3N22013:China,H7N9serotypesH5andH7areconsideredhighlypathogenicinpoultry.SectionⅢSARS-CoVAnovelcoronavirus120-160nm,+ssRNA(29.7kb),envelopedMajorstructures:N,S,MTransmission:

aerosolordroplet

Associateddiseases:SevereAcuteRespiratorySyndrome(SARS)SARS-CoVClinicalfeaturesX线片出现单侧或双侧肺部阴影呼吸窘迫、呼吸衰竭CharacteristicpropertiesofcommonrespiratoryvirusesvirusesShapeandstrectureNo.ofserotypesdiseasesDiameter(nm)NucleicacidEnvelopeH,NInfluenzavirus80-120ssRNA+variable3Influenza,Commoncold,BronchitisParainflu-enzavirus120-200ssRNA+

4CommoncoldCroupPneumoniaMeaslesvirus120-150ssRNA+H(+)N(-)1Measles,SSPEMumpsvirus100-200ssRNA+

1Mumps,Meningitis,OrchitisRespiratorysyncytialvirus125-250ssRNA+_1Bronchiolitis,PneumoniaRubellavirus60-70ssRNA+

1rubellaandCRSRhino-virus28-30ssRNA_

>110CommoncoldCorona-virus80-100ssRNA+

>3CommoncoldReovirus60-90dsRNA_

3Upperresp.tractinfection,diarrheaAdeno-virus70-90dsDNA_

Acuteresp.disease,Pneumonia,diarrhea,Conjunctivitis>100Koplik斑measlesMumpsfollicularconjunctivitis

adenovirusRespiratoryviruses

Influenzavirus-ssRNAInfluenza

(segmented)Measlesvirus–ssRNAMeasles(SSPE)Mumpsvirus-ssRNAMumpsParainfluenzavirus-ssRNACommoncold,CroupAdenovirusdsDNAPharyngoconjunctivalfever,etcRubellavirus+ssRNARubella

(congenitalrubellasyndrome)Respiratorysyncytial-ssRNABronchiolitis,pneumoniavirus(themostimportantcauseoflowerrespiratorytractdiseaseininfantsandyoungchildren)Rhinovirus+ssRNACommoncoldCoronavirus+ssRNACommoncoldSARS-CoV+ssRNASARSChapter24Gastrointestinalinfectionvirus胃肠道病毒Picornaviridae：

enterovirusReoviridae：

rotavirusother：

astrovirus,entericadenovirus,calicivirusClassification:

Poliovirus:3serotypes

Coxsackievirus:GroupAandGroupB29serotypes

ECHOvirus:31serotype

NewEnteroviruses:serotype68.69.70.71.72SectionⅠEnterovirusesCommonProperties:1)

Spherical,20-30nm,icosahedralsymmetry,non-enveloped,+ssRNA

2)

cellculture(causeCPE)3)

resistance:morestable,resistanttoliposolvents,pH3-5,resist56℃30min

4)Pathogenesis:virus---enteron--viremia----differenttargettissues.1.Threeserotypes,non-crossreaction2.fecal–oraltransmission3.CausePoliomyelitis

4.Immunity:neutralizationAb

5.

Vaccine

Poliovirusincubationperiod:7-14days(range3-35days).Followingingestion----oropharyngealandintestinalmucosa(lymphaticsystem)atransientviraemia.CNSfollowingdissemination.Pathogenesisoutcomesfollowingpoliovirusinfection:

Subclinicalinfection(90%)Abortiveinfection(5%)nonparalyticpoliomyelitis

(1-2%)

permanentflaccidparalysis

(0.1%)

VAPP:vaccineassociatedparaliticpoliomyelitis

Inactivatedpoliovaccine(IPV，Salk,1954)Oralpoliovaccine(OPV,attenuatedlivingvaccine，Sabin,1957)

Vaccine:Diseasescausedbyenterovirusesviruses

Type

ClinicalillnessPolioviruses1-3ParalysisCoxsackievirus

A1-24B1-6Paralysis,Asepticmeningitis,Herpangina,Hand-foot-mouthdisease,Myocarditis,pleurodyniaetcEchoviruseses

1-31Asepticmeningitis,Myocardit