病原微生物学资料：第一次网络考试题目和答案

1.AGramstainhasbeenperformedonabacterialisolatetakenfromasheepbloodagarplate.

Uponobservation,thecellsappeartoberedtopinkrods.Theorganismispresumptively

identifiedasCitrobactcrkoseri（克氏柠檬酸杆菌）.Themostlikelyreasonfortheredcolorofthe

cellsin（hestainisthatthe（A）

APeptidoglycan（肽聚糖）layerofthecellwallisrelativelythin

BPeptidoglycanlayerofthecellwallisrelativelythick

COrganismsinthisgenushavealipopolysaccharideoutermembrane

DOrganismsinthisgenushaveonlyacytoplasmicmembrane

ECapsule（英膜）tendstocapturethesafraninfromtheGramstainreagent

2.Themedicalimportanceofspores（芽胞）liesinthefactthat:（C）

ATheyhavekeratin（角蛋白）-likecoats.

BTheycontainbacterialDNA.

CTheyareextremelyresistanttoheatandchemicals.

DTheyareformedinadverseconditions.

3.CASE:A13-ycar-olcgirlwasadmittedtoahealthcarefacilitywitha5-hourhistoryof

diarrhea（腹i1写）andvomiting（口区吐）.Onpatientinterview,thephysiciansuspectedittobean

infectionbycontaminatedfood.Thephysicianrecommendeddiagnosticteststobedoneforthe

patient.MicroscopicexaminationofthestoolonGramstainingrevealedGramnegativebacilli.

Themicrobiologistdiscoveredshort,slender（瘦长的）rodsduringmicroscopicexaminationand

suspectedtheorganismtobeEscherichiacoli.Whichamongthefollowingmediahelpsin

differentiatingE.colifromothergeneraofentericbacteria?（B）

ASheepbloodagar（SBA）

BEosinmethyleneblue（EMB）agar

CChocolateagarplate

DLiquidmedia

4.ThetoxinofCorynebacteriumdiphtheriae（白喉棒状杆菌）isresponsibleforthe

vaccine-preventablechildhoodillnessdiphtheria（白喉）,Toxinproductioninthisorganismis

mediatedbychromosomalgenesthatoriginatedfromabacteriophage.Whenincorporatedintothe

DNAofahostcell,bacteriophageDNAiscalledaprophage（原噬菌体）.Organismsthatcontain

theprophageproducethetoxinandcausediphtheria,whilethosethatdonotcontaintheprophage

areprobablynonpathogenic.ThismechanismofDNAtransferfromonecelltoanotherbywayof

abacteriophageiscalled（A）

ATransduction（转寻）

BTransformation（转化）

CConjugation（接合）

DTransfection（转染）

ERecombination（重组）

5.A5-year-oldboyistakentoaphysicianafterhisinsectbitegetsinfected.Thedoctortakesa

specimenfromthelesionforcultureandacatalase（触酶）-positive,Gram-positivebacteria

growinginclustersisisolated.Whatelseisafeatureofthisorganism?（E）

ACanmakespores

BProducesgamma-hemolysisonbloodagar

CCanonlygrowanaerobically

DProducesapotentendotoxin

ECanfeimentmannitol（甘露糖）andgrowonhighsalt

6.A39-year-oldwomancomesintoyourofficebecauseshehashadseverediarrheaforthepast

2days,accompaniedbyfeverandashakingchill.Sheusesantacids（抗酸药）.Otherwisesheis

healthy.Astainforfecal（粪便）leukocytes（白细胞）revealsmanyPMNs（中性粒细胞）.Test

foroccultblood（便除血）waspositive.Fromthestoolcultureagram-negativerodwasisolated

thatdoesnotfermentlactose（乳糖）.Triplesugariron（TSI）agarshowsanalkalineslant,acid

butt,withbothgasandH2s.Theurease（尿素酶）testwasnegative.Whichoneofthefollowing

organismsis（hemostlikelycause?（A）

ASalmonellatyphimurium（鼠伤寒沙门氏菌）

BEscherichiacoli

CCampylobacterjejuni（空肠弯曲菌）

DVibrioparahacmolyticus（副溶血弧菌）

EVibriocholerae

7.AmanbringshisuncletoyourofficeandtellsyouthattheunclelivesintheCaribbean（加勒

比海）butisintheUnitedStatesonvacation.Hecomplainsofaverysorethroatandhas

problemsswallowing.Thelymphglands（淋巴腺体）inhisneckareveryswollen（肿大）.You

suspectthathehasdiphtheria,whichisconfirmedbyathroatculture.Onedomainofthetoxinis

involvedintheinhibitionofproteinsynthesis.Aseconddomainisinvolvedin（A）

Atoxinbinding（othecellreceptor

BinhibitingDNAreplication

Ccleavageof（he285ribosomalRNA

Dbindingandsequesteringelongationfactors

Etransportingtoxinintothenucleus

8.Staphylococcalbacteriacauseawidevarietyofhumandisorders,fromfoodpoisoningto

rashes（发疹）.Somestrainsofstaphylococcicausetoxicshocksyndrome（TSS）,amultisystem

disease.ThecauseofTSSisatoxincalledtoxicshocksyndrometoxin1（TSST-1）,originally

recognizedasoneofthepyrogenic（化脓性）staphylococcalenterotoxins.Ilisoneofagroupof

toxinsknownaswhat?（A）

ASuperantigens（超抗原）

BImmunotoxins［免疫毒素）

Chnmunophilins（亲免素）

DToxoids（类毒素）

ERTXtoxins（在细胞膜上打孔的外毒素）

9.Anexperimentisdevisedtostudytheinvitroeffectsofcytokinesandotherchemokinsson

macrophages.Recombinantinterferonsalpha,beta,andgamma,interleukin-1,interleukin-2,

interleukin-4,interleukin-6,granulocytemacrophagecolonystimulatingfactorandtumorgrowth

factorbetawereaddedindividuallytomacrophages.Whichofthefollowingcytokinesor

chemokinesactivatemacrophagesbyamechanismthatinvolvesincreasedionexchange?（F）

AIntcrferon-alpha,intcrfcron-bcta,andintcrfcron-gamma

Binterleukin-1

CGranulocytemacrophagecolonystimulatingfactor

DTumorgrowthfactor-beta

EInterferon-beta

Finterferon-garnni£

Ginterleukin-2

Hintcrlcukin-4

Iinterleukin-6

10.A36-year-oldAmericanIndianisadmittedtotheisolationunitatyourhospitalibrtreatment

ofpulmonarytuberculosis,whichwasdetectedataroutinecheckupthedaybefore.Heworksata

constructionsite（建筑］:地）downtown（市中，心）andhasnotbeenincontactwithanyfarm

animals.Besidestreatment,youneedtoinformhimofthemostcommonwayoftransmittingthe

disease.Whichcontaminationisusuallyresponsible?（E）

ABloodcontact

BHands

CEatingutensils（餐具）

DMilkproducts

EDropletnuclei（飞沫核）

11.Anelderlywomanwasadmittedtothehospitalforasepticwoundtreatmentonherlower

abdomenwhichdevelopedafteracolonoperation.Herwoundwas1.5-cmopen,andoozing（渗

出）ayellowexudate（分泌液）.Whichisthebestwayofsterilizing（消毒）thesheetofthebed

（床单）contaminatedwith（hesepticwound'ssecretion?（D）

AUsinganionicagentsolvents（阴离子溶剂）

BUsingnonionicagentsolvents（非离子型表面活性剂的溶剂）

CDryheatsterilization（干热灭菌）

DAutoclavesterilization（湿热灭菌）

ERadiation（辐射）

12.A30-year-oldmancomesintoyourofficebecauseofdiarrhea（腹泻）thatbeganon（he

airplanewhilehewasreturningfromavacationintheMiddleEast.Hehadmultipleepisocesof

watery,non-bloodydiarrheaandlittlevomiting.BP130/85inmHg,P76,T36,8℃.Youmakea

stainforfecalleukocytes,whichrevealsnoPMNs.Testforoccultbloodisnegative.Cultureofthe

stoolrevealspigmented（有颜色的）coloniesoneosin-methyleneblue（EMB）agar.Whichoneof

thefollowingorganismsisthemostlikelycause?（A）

AEscherichiacoli（enterotoxigenicstrains）

BEscherichiacoli（enteropathogenicstrains）

CEscherichiacoli0157:H7

DS.typhimuriuin

ES.dysenteriae

13.WhichofthefollowinggroupofEscherichiacoliisthecommoncauseofdiarrheaininfants

andisimplicatedinoutbreaksofdiarrheainnurseries?(C)

AEnterotoxigenic

BEnteroinvasive

CEnteropathogenic

DEnterohemorrhagic

EEnteroaggregative

14.ThemajorpropertythatdistinguishesE.colifromthetwootherintestinalpathogensShigella

andSalmonellaisthatitferments(A)

ALactose

BMaltose

CFructose

DGlucose

EAcetate

15.A45-year-oldwomancomesintoyourofficewitha2-dayhistoryofabdominalcrampsand

bloodydiarrhea.ShehasjustreturnedfromhervacationinIndia,wheresheatemanyofthelocal

foods.Herbloodpressureis120/80mmHg,pulserateis84/minute,andtemperatureis37.8°C.

StoolexaminationrevealsmanypolymorphonuclearleukocytesandaerobicGramnegative

non-motileorganisms.Fromthestoolculture,aGram-negativerodwasisolatedthatforms

colorlesscoloniesoncosin-mcthylcncblue(EMB)agar.Whatorganismisthemostlikelycause?

(A)

AShigelladysenteriae

BEscherichiacoli

CVibriocholerae

DVibrioparahaemolyticus

EYersiniaenteiolitica(黑死病致病菌耶尔森菌)

16.Whichofthefollowinggram-negativerodsarefoundinseawaterandare(hecommoncause

oftoxigenicwater-lossdiarrhea?Thesebacteriaarehighlymotilewithasinglepolarflagella.

(A)

AVibriocholerae(霍乱弧菌)

BProteusmirabilis(奇异变形杆菌)

CShigellaflexneri(弗氏志贺菌)

DEscherichiacoli

17.6hoursaftereatingrawfishandotherseafoodataJapaneserestaurant,acoupledeveloped

nauseaandvomiting,waterydiarrhea,abdominalcramps,andFever.Whatorganismislikely

involvedinthepatients'condition?(E)

ASalmonellaenteritidis(肠炎沙门氏菌)

BBacilluscereus(蜡样芽胞杆菌)

CClostridiumpcrfringcns（产气芽胞梭菌）

DStaphylococcusaureus

EVibrioparahacmolyticus（副溶血弧菌）

18.TheantibioticrecommendedbyCentersforDiseaseControl（CDC）fortreatmentof

gonorrheais（B）

APenicillin

BCeftriaxone（头泡曲松）

CErythromycin（红霉素）

DTetracycline（四环素）

EAminoglycosides（氨基糖戒,类）

19.BiologicactionsofProteinIassociatedwithgonococciinclude（B）

AAntiphagocyticactions

BFormationofsurfacepores

CAttachmenttohumancellslikeepitheliumofvagina

DHydrolysisofp-lactamringinpenicillin

EIronbinding

20.Asexuallyactive18-year-oldmanattendsagenitourinarymedicineclinic（泌尿生殖医药门

诊）withacomplaintofpainfulurethraldischarge（尿道物）.Afterappropriatestudies,a

diagnosisofgonorrhea（淋病）ismade.Whichofthefollcwingwouldmostlikelybefoundona

smearofhisdischarge?（D）

AGram-positiverods

BGram-negativerods

CGram-positivecocci

DGram-negativecocci

EAcid-fastbacilli（抗酸细菌）

21.Gramnegativediplococcialongwithlargenumberofpolymorphonuclearneutrophilswere

seeninthecerebrospinalfluidofa21yroldmalehavingsymptomsofpurulentmeningitis.The

coloniesonchocolateagarwerecatalasepositiveandoxidasepositive.Theisolateproducedacid

fromglucoseandmaltose（麦芽糖）butnotfromsucrose（蔗糖）andlactose.Thecausative

organismis（C）

AStreptococcuspneumoniae（肺炎链球菌）

BStreptococcusagalacliae（无乳链球菌）

CNeisseriameningitidis

DNeisseriagonorhoeae

EEscherichiacoli

22.Speciesofspore-fbrmingbacteriabelongingtotheClostridiumgenusincludeseveral

pathogensofmedicalimportance.Whichofthefollowingisthemostlife-threatening

characteristicofsuchbacteria?（C）

ALackofprophylacticvaccines

BFeverproduction

CProductionofexotoxins

DInvasivepotential

EFormationofendospores

23.Thetetanospasmin(破伤风痉挛毒素)(C)

Aisapotentendotoxin

Bisaheatstableprotein

Ccausescontinuousexcitationofmotorneurons

DAandC

EBandC

24.A1O-year-oldboyisbroughttotheemergencyroombyhismother.Hehasa4-dayhistory

ofmalaise,sorethroat,anorexia,andlow-gradefever.OnPE,pharyngealinflammationandagrey

pseudomembranecoveringthetonsilsarevisualized,whichbleedsontryingtoremoveit.Culture

showsblackcoloniesandsmearshowsclub-shapedgrampositiverods.Howdoesthetoxin

producedbythisbacteriaact?(D)

AItdecreasesglycineandgammaaminobutyricacidbyproteincleavage

BItincreasescAMPbyADPribosylationofGi-alfaprotein

CItincreasescAMPbyADPribosylationoftheGs-alfaprotein

DItinhibitstheproteinsynthesisbyaddingADP-ribosetotheelongationfactor2

EItstimulatesadenylatecyclasebyADPribosylationofGTPbindingprotein

25.Whichofthefollowinganaerobeisassociatedwithproductionofdoublezoneofhemolysis?

(A)

AClostridiumpertringens

BClosiridiuindifficile

CClostridiumsepticum

DClostridiumtetani

EClostridiumsordellii

26.Diphtheriatoxinactsby(A)

AInhibitingproteinsynthesis

BBlockingmRNAbinding

CProducingedema(水肿)

DIncreasingtranslation

27.DPTvaccinecontains(A)

AToxoidfordiphtheriaandtetanusandheatkilledorganismsforwhoopingcough

BToxoidfortetanusandheatkilledorganismsfordiphtheriaandwhoopingcough

CToxoidforwhoopingcoughandtetanusandheatkilledorganismsfordiphtheria

DToxoidfordiphtheria,tetanusandwhoopingcough

EHeatkilledorganismsfordiphtheria,tetanusandwhoopingcough

28.Coryncbactcria(棒状菌)arc(B)

AMotile

BCatalasepositive

CSporeformers

DDonotfermentcarbohydrates

EStrictanaerobes

29.Corynebacteriaare(C)

ASmall,pleomorphicgram-negativebacilli

BMotile

CNon-sporeformers

DDevoidofmycclicacid(无分枝菌酸)

EStrictanaerobes

30.Amantadine(金钢胺),usedfortheprophylaxisofinfluenza,functionsbywhichofthe

followingmechanisms(E)

AInhibitionofviraltranscription

DInhibitionofviraltranslation

CNeutralizationofextracellularviralparticles

DInhibitionof(hereleaseofviralpanicles

EInhibitionofpenetrationofthecellmembraneofthetargetcell

31.Theseenveloped,pleomorphic(多形'性)，andss-RNAvirusescauserespiratoryinfectionsby

dropletnucleiorcontacttransmission.Thesebelongtotheorthomyxovirusgroupandarecalled

what?(B)

ALcntiviruses

BInfluenzavirus

CParainfluenzavirus

DRespiratorysyncytialvirus

32.Whichofthefollowingarestructurallymostcloselyrelatedtotheinfluenzavirus?(C)

ARetroviridae

BTogaviridae

CParamyxoviruses

DCoronaviridae

ERhabdoviridae

33.Whichofthefollowingarestructurallymostcloselyrelatedtotheinfluenzavirus?(C)

ARetroviridae

BTogaviridae

CParamyxoviruses

DCoronaviridae

ERhabdoviridae

34.Althoughtheusualwayinwhichaparticleentersacellisbyphagocytosissothatthe

particleisenclosedinaphagocyticvacuole,thereareothermethodsofentry.Ifvirusesentercells

byphagocytosis,theyarcdestroyedbyhydrolyticenzymes.Howdomostnoncnvclopcdand

envelopedvirusesentercells?(A)

AEndocytosis

BOpsonization

CNeutralization

DPhagocytosis

EPinocytosis

35.Aninvitroexperimentisdesignedtoexaminethesequentialstepsinvolvedinviral

infectionandreplication.Givenhealthyviablecellsandvirus,whichofthefollowingaccurately

describesthecorrectsequenceofstepsinviralinfectionandreplication?(C)

Auncoating,attachment,biosynthesis,penetration

Battachment,uncoating,penetration,biosynthesis

Cattachment,penetration,uncoating,biosynthesis

Duncoating,attachment,penetration,biosynthesis

Euncoating,penetration,attachment,biosynthesis

36.Youarestudyingavirusisolatedinthelaboratoryfrommouseepithelialcells.Thegenetic

materialfromthisvirusisexaminedandfoundtocontainadenine,guanine,cytosine,anduracil,

butnothymine.Youbegintostudythemechanismofreplicationofthisvirus.Basedonthefact

thatthegeneticmaterialofthisviruscontainsuracil,whatistheenzymeuniquetothesetypesof

virusesthathelpsformdouble-strandedDNA?(C)

AGuanylatecyclase

BIntegrase

CReversetranscriptase

DTopoisomerase

EDNAligase

37.Abasicscientistatamedicalschoolisinterestedinevaluatingamouseforexposuretoa

virus.Severalsamplesoftissuesandcellsaretakenforanalysis.Whichofthefollowingmethods

forassessingviralexposureisbasedonanindirectmeasurement?(B)

ADetectionofviralDNAorRNAincells,serum,ortissues

BDetectionofantiviralantibodiesinthebloodortissues

CDetectionofintracellularviralantigens

DDetectionofvirusparticles

EVisualizationofvirionsbyelectronmicroscopy

38.Althoughprimarytuberculosisisofthegreatestconcerntomostphysicians,sonicpatients

whohavebeenpreviouslyinfectedwithMycobacteriumtuberculosismayexperiencesecondary

orreactivationdisease.Themostlikelyexplanationforthereactivationofthisdiseaseinpatients

is(D)

AThereisalocalactivationofthehumoralimmuneresponseandaconcomitant

activationofthecomplementsystemthatinitiatesthebreakdownofolder,calcifiedlesionsinthe

lung,leadingtothereappearanceofsymptoms

BBecauseofthecontinuedexposureoftheetiologicagenttolongtermtherapywith

multipleantiluberculosisdrugs,secondarydiseaseemergeswhenantibioticresistantstrainsofM.

Tuberculosisreachacriticalmassinadormantlesionandthenbreakthroughtoreinitiate

symptoms

CTheinfluenceofpulmonarydiseaseotherthantuberculosis,suchasbacterial

pneumonia,promotesaB-cellresponsethatinitiatesthebreakdownofthecalcifiedlesionsinthe

lung

DTherecrudescenceofdormantfocifromtheprimaryinfectionisassociatedwitha

localbreakdownofthecellularimmunesystembyfactorssuchasage,diabetesmellitus,or

obstructivepulmonarydisease.Becauseofthehostshypersensitivitytothetuberculoprotein,the

localizedlesionbecomesnecroticandundergoesliquefaction

EThedormant(休眠的)focithroughoutthelungsundergoanaturalagingprocess

wherebychangesintheultrastructureofthecalcifiedlesioninitiatea"leakage"oforganisms.

Generally,therecrudescenceisnotinfluencedbytheimmunestatusofthehost

39.Mycobacteriumtuberculosis(C)

AIsacidfastduetoverylowlipidcontentofcellwall

BIsanobligateanaerobe

CHascordfactorandsulfatideproduct,whichcontributestovirulence

DCannotsurviveinsidenormalmacrophage

EProducesendotoxins

40.A7-montholdchildpresentstotheemergencyroomexhibitingtoxicepidermalnecrolysis

andlarge,flaccidbullaethatareformingandrupturingundertheepidermis,causingdesquamation

inthediaperarea.Thisspectrumofdiseasedescribesaconditionusuallycausedby:(A)

AToxinproducingStaphylococcusaureus.

BInvasiveEscherichiacoli.

CProphageinfectedCorynebacteriumdiphtheriae.

DFlesh-eatingStreptococcuspyogenes.

EDermalinfectionwithClostridiumperfringens.

41.A32-year-oldwomanisbroughttotheemergencyroomwithsuddenonsetof:ever,

headache,sorethroat,profusewaterydiarrhea,vomiting,andlethargy,whichstartedinthe

morning.Onphysicalexamination,sheisslightlyconfused,hertemperatureis39°C(103°F),

herbloodpressureis100/50mmHgandshehasdiffusesunburnlikeaerythematousrash.When

theemergencydoctoristryingtofindoutifsheispregnant,shementionsthatherperiodstarted2

daysago.Whichofthefollowingisihemostlikelydiagnosis?(D)

AScarletfever(猩红热)

BRockyMountainspottedfever

CMeningococceinia

DToxicshocksyndrome

EFoodpoisoning

42.CASE:A38-year-oldmanwasadmittedtoahealthcarefacilitywithnausea,vomiting,

diarrhea,andabdominalcrampingforthepast2hours.HisBPwas100/60nunHg.On

interviewingthepatient,herevealedthathehadconsumedmeatthathadbeenleftuncoveredfora

night.Thephysiciansuspecteditasacaseoffoodpoisoning.Duringlaboratoryexaminationit

wasfoundthatthemeatwascontaminatedwithcircular,clusteredorganisms,whichonGram

stainingwerefoundtobeGrampositive.Fairlylarge,yellowcoloredcolonieswerefbimedwhen

(heorganismwasgrownonmannitolagarmediainatemperaturerangeof15to45℃.The

organismshowedpositiveresultsforcoagulaseenzymeactivityandshowedresistanceto

penicillinandmethicillinantibiotics.

Whatorganismwasthecausativeagentofthefoodpoisoning?(D)

AClostridiumpeifringens

BEnterococcusfecalis

CEscherichiacoli

DStaphylococcusaureus

ESalmonellaspecies

43.CASE:Apreviouslyhealthy24-ycar-oldwomanpresentedwithhighfeverofsuddenonset,

severemyalgia(肌肉疼痛),headache,vomiting,diarrhea,anddiffusescarlatini-formrash

resemblingsunburns.Shewasonthefourthdayofhermensesandwasusingtampons(卫生棉

塞).Herbloodpressurewasnotedas70/40mmmercury.Aspartoflaboratoryinvestigations,

blood,urine,andvaginalculturesweredone.Accordingtothemicrobiologyreport,heavygrowth

ofstaphylococcusaureuswasobtainedfromvaginalculture.Preliminaryreportofherblood

cultureshowednogrowthafter24hrsincubation.Microscopyofurinesedimentshowed15

leucocytesperhighpowerfield.Urineculturedidnotyieldanysignificantgrowth.

Whichofthefollowingstaph