an atlas of protozoan parasites in animal tissues

7/28/2019 An Atlas of Protozoan Parasites in Animal Tissues

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UnitedStatesDepartmentofAgricultureAgriculturalResearchService Agriculture HandbookNumber651

AnAtlasofProtozoanParasitesinAnimalTissues C.H.GardinerR .PayerJ.P.Dubey

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C.H . ,R.Payer ,andJ .P .Dubey . 1988.atlasofprotozoanparasitesnanimalissues. U.S.ofAgriculture,AgricultureHandbookNo.83 .atlasllustratesprotozoanparasitesnanimal

Tofacilitateidentification,tprovidesabriefofparasites,hosts,ransmission,and ofthemostmportantprotozoansand ife-cycledrawings.Alsoincludedare25 7photographsofprotozoansandassociatedecordedusingoptimalconditionsforiden-

and36colorphotomicrographsoffungithatcommonlyconfusedwithprotozoans.

Acanthamoeba,Akiba,Anaplasma,Balantidium,Besnoitia,Calyptospora,Cryptosporidium,Cystoisospora,Cytaux-Ehrlichia,Eimeria,Encephalitozoon,Entamoeba,Giardia,Glugea,Haemogregarina,Hammondia,Hepatocystis,Hepatozoon,Histomonas,chthyophthirius,sospora,Leishmania,Leucocytozoon,Myxosoma,Pentatrichomonas,Plasmodium,Sarcocystis,Spironucleus,Theileria,Tox-Trichomonas,Trypanosoma.

CopiesofthispublicationcanbepurchasedromtheSuperintendentofDocuments,U.S.GovernmentPrintingOffice,Washington,DC20402.MicrofichecopiescanbepurchasedromtheNationalTechnicalnformationService,5285Por tRoya lRoad,Springfield,VA 22161 .AgriculturalResearchServicehasnoadditionalcopiesforfreedistribution.

Tradenamesareusednthispublicationsolelyforthepurposeofprovidingspecificnformation.MentionofatradenamedoesnotconstituteaguaranteeorwarrantyoftheproductbytheU.S.DepartmentofAgricultureoranendorsementby theDepartmentoverotherproductsnotmen-tioned.

Apr i l1988


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Preface Acknowledgments

Identificationofprotozoanparasitesnaninnalissuesisoftendifficultandconfusing.Sometimestsm-possible.Theresnosingleeferencecontammgl-lustrationsofthenumerousspeciesofprotozoansandtheirstagesastheyappearwithinnfectedtissues.Th ententofthisatlassofillhisvoidby providingcolorphotomicrographsoftheseorganismspreparedby techniquesthatbestdentifythem.Tofur-therfacilitatedentification,wehavencludedsimplifiedife-cycledrawingsandbriefdescriptionsoftheparasites,hosts,ransmission,andpathogenesis.Th eillustrationsnthisatlasepresenthemostcom-monstagesunderoptimalconditionsoridentification.Toobtainthem,wehaveutilizedreshaswellasixedandstainedspecimens.Mostprotozoanscanbereadi-lydentifiednissuesstainedwithhematoxylinan d eosin(H&E)an dobservedwithbrightfieldmicroscopy.Therefore,mostllustrationsnhisatlasshowsuchspecimens,andnonotationofthisstainsmadenthelegends.dentificationofotherprotozoanssfacilitatedbyspecialstains,suchasGiemsa,Protargol,ron-hematoxylin,periodicacid-Schiff(PAS)reaction,PAS-hematoxylin(PASH),Gram,acid-fast,Gomorimethanaminesilver,an dtrichrome.whicharenotednth eegends.Stillotherprotozoansar ebestseenby phasecontrastorNomarskinterferencecontrastmicroscopyorbyelectronmicroscopy.Anaplasmaan dEhrHchia,historicallyassociatedwithprotozoansbutnowknowntoberickettsiae,aren- cludedtoaidndifferentialdiagnosis.Becauseofdif-ficultyndifferentiatingsomefungiromprotozoans,severalplateshavebeenprovidedollustratethosefungi.Eachplatesabeledascolor(CP)orblackan dwhite(BW)an dsnumberedsequentially.Eachphotographhas aplatenumberfollowedbyadecimalndicatingtsplacementwithinheplate.Furthermore,nearlyevery colorphotosdentifiedntheegendwithamedicall-lustrationnumbernparentheses.ThisnumberreferenceshellustrationonileatheArnnedorcesn- stituteofPathology.

Weexpressourappreciationothehundredsofscien-tistswhocontributedbiologicalspecimensormicroscopeslidesofprotozoanparasitestotheRegistryofVeterinaryPathology,ArmedForcesn-stituteofPathology,romwhichmanyphoto-micrographsweremade. Wealsoexpressappreciationothefollowingassociateswhoprovidedtissues,mountedspecimens,transparencies,ornformation:P.O.Beaver ,TulaneUniversity,NewOrleans,LA;R.J .Cawthorne,RegionalVeterinaryCollege,PrinceEdwardsland,Canada;M.LEberhard,DeltaRegionalPrimateCenter,Covington,LA;J .V.Ernst,AnimalParasitologynstitute,Beltsville,MD;P.R.Fitzgerald,Universityofllinois,Urbana,L; J .K.Frenkel,UniversityofKansasMedicalCenter,Kan-sasCity,KS;P .C .C .Garnham,LondonSchoolofTropicalMedicineandHygiene,Ascot,England;W.J .Hartley,WallacevilleAgriculturalResearchCenter,UpperHutt,NewZealand;G.D.mes,ArmedForcesn- stituteofPathology,Washington,DC ;R.G.Leek,AnimalParasitologynstitute,Beltsville,MD;N.D.Levine,Universityofllinois,Urbana,L;D.S.Lindsay,AuburnUniversity,Auburn,AL;R.C.Neafie,ArmedForcesnstituteofPathology,Washington,DC ;R.M.Overstreet,GulfCoastResearchLaboratory,OceanSprings,MS;M.Rommel,nstituteforParasitologyoftheHannoverVeterinaryCollege,Hannover,FederalRepublicofGermany;L.T.Sangster,VeterinaryDiagnosticLaboratory,Tifton,GA;C.A .Speer ,MontanaStateUniversity,Bozeman,MT;R.S.Wacha,Drake University,DesMoines,A;andR.G.Yaeger,TulaneUniversity,NewOrleans,LA .WethankR.B.Ewing,AnimalParasitologynstitute,Beltsville,MD,ortheife-cycledrawingsandJ .E.Luscavage,ArmedForcesnstituteofPathology,Washington,DC ,orthephotomicrographsofmostofthespecimens.

Acharthasbeenncludedofacilitatedentificationofcoccidiangenera,basedonthemorphologyofthesporulatedoocysts.Wehopethisatlaswillaidstudents,teachers,diagnosticians,andesearchersbyfacilitatingden-tificationofprotozoanparasitesofanimals.


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Conten ts

SarcomastigophoraLeishmania 3Trypanosoma 3Flagellates 6 Histomonas 8Amoebae 10

Microspora 12Myxozoa 14Ciliates 1 6 Pneumocystis 18

Apicomplexa 20 Eimeria 20Isospora 31 Cd ryo spora 34Cryp tosporidium 36 Sarcocystis 40 Frenkelia 46 Besnoitia 48 Toxoplasmaand Hammondia 5 2

Coccidiaofundeter-minedtaxonomicstatus 5 6

Klossiella 6 0Haemogregarina 6 2Hepatozoon 6 2Plasmodium 6 4 Hepatocystis 6 6 Theileria(syn.,Cytaux-zoon) 6 8

Babesia 70 Haemoproteus 72 Leucocytozoon 72 Haemosporozoaofun-

determinedtaxo-nomicStatus 74

Fungi 76 Indexofprotozoanparasitegenera 83

Colorplates 1 .eishmaniap p .andTrypanosomaspp.of

animals 5 2.lagellatesofanimals 73.Histomonasmeleagridisofchickens 94.moebaeofanimals 1 1 5 .Microsporaofanimals 136 .Myxozoaoffish 1 5 7.Clliatesofanimals 178.Pneumocystissp .ofmammals 199.Eimeriaspp.ofchickens 22 10.imerianecatrixofchickens 231 1 .Eimeriaspp.ofbirds 24 12./mer/aspp.ofbovines 25 1 3.Eimeriap p .ofsheep 26 14.Eimeriaspp.ofsheepandgoats 27 1 5 .Eimeriaspp.ofhorses,deer ,andgoats 28 1 6 .Eimeriaspp.ofwallabiesandsnakes 29 17.Eimeriap p .ofrabbitsandmink 3018.sosporaspp.ofpigsandbaboons 3219.sosporaspp.andCystoisosporap p .ofmam-

mals 33 20 .Caryosporabigeneticaofsnakesandmice 35 21 .Cryptosporidiumspp.ofanimals 3722 .Cryptosporidiumspp.ofcalves 3823 .Sarcocystiscruzi{syn., .bovlcanis)ofcaninesand

bovines 41 24 .Sarcocystiscruzi(syn.,S.bovlcanis)ofbovines 42 25 .Sarcocystisspp.ofbovines 43 26 .Sarcocystiss p p .ofvariousanimals 44 27 .renkeliamicrotiofbirdsandodents 47 28 .esnoitiaspp.ofanimals 49 29 .esnoitiaspp.ofanimals 5 030.es/70/f/a-likeorganismofknots 51 31 .oxoplasmagondiiofanimals 5 3

32.oxoplasmaandHammondiaofanimals 5433.oxoplasmaabortionofsheep 5 5 34.Coccidiaofundeterminedaxonomicstatuscausing

encephalomyelitisofdomesticanimals 5 735 .Coccidiaofundeterminedtaxonomicstatusofanimals 5 8

36 .Calyptosporaandorganismsofundeterminedtaxonomicstatusofanimals 5 937.Klossiellaspp.ofanimals 61 38.Haemogregarinap .andHepatozooncanisof

animals 6 3 39.Plasmodiumspp.ofbirds 6 5 40 .Plasmodiump .andHepatocystisp .ofnon-

humanprimates 6 7 41 .heileriaells(syn.,Cytauxzoonelis)ofcats 6 942 .Iroplasmsandickettsiaeofanimals 71 Haemosporozoaofbirds 73 Haemosporozoaofbirds 75 HistopiasmacapsulatumandCandidaalbicansof

animals 77 Rhinosporidiumseeberlofdogs 78 47 .EmmonsiacrescensandSporothrixschenckliof

animals 79 48 .CoccidioldesImmltisandProtothecap .ofani-mals 80

CryptococcusneoformansandParacoccidl-oidesbrasillensisofanimals 81

BlastomycesdermatitidlsandLoboaobolofanimals 82

43 .44 .45 .46 .

49 .50,

Blackandwhiteplates 1 .imerianifecycle 21 2.lectronmicrographsofCryptosporidiump .ofsheep 393.lectronmicrographofSarcocystisofsheep 45


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AnAtlasofProtozoanParasitesinAn ima lTissuesByC .H .Gardiner, .Payer ,andJ .P .Dubey^

Protozoansareunicellularaninnals.Mostareverysnnall(10-20 x n nndiameter),nnanyaresonriewhatarger(100-200 i t n n ) .Evenhoughheyareunicellular,sonnestagesntheirlifecyclennayappearnnulticellular,suchasacystofSarcocystis, nnegaloschizontofLeucocyto-zoon,andamerocystofHepatocystis.Lifecyclesare oftenntricate.Theynnayinvolveone,two,ornnorehosts;vectorsmaybenecessaryfortheirspread;andmanysizesorshapesoforganismsmaybepresent.Thefollowingannotatedclassification^includesonlytheprotozoansnthisatlas.SubkingdomProtozoa

PhylumSarcomastigophoraflagellaorpseudopodiaSubphylumMastigophoraflagellan

trophozoitesClassZoomastigophoreanochromato-

phoresOrderKinetoplastidakinetoplast

FamilyTrypanosomatidaebodyypi-callyleaflikebutmayberounded

GenusLeishmaniaGenusTrypanosoma

OrderDiplomonadidabilaterallysym-metrical,twosimilarnuclei

FamilyHexamitidaebodybilaterallysym-metrical,sixtoeightlagella

GenusSpironucleus(syn. ,Hexamita)GenusGiardia

OrderTrichomonadidafourtosixlagella,onetrailing,nocysts

FamilyTrichomonadidaeundulatingmembrane,trailinglagellum,costapresent

GenusTrichomonasFamilyMonocercomonadidaecosta

absent,recurrentflagellumfreeGenusHistomonas

^C .H .Gardiner,RegistryofVeterinaryPathology,ArmedForcesnstituteofPathology,Washington,DC20306,an dR. Paye randJ . P .Dubey ,AnimalParasitoiogynstitute,BeltsvilleAgriculturalResearchCenter,Beltsville,MD0705.Theopinionsorassertionscontainedhereinaretheprivate

viewsoftheauthorsan darenottobeconstruedasofficialorasnecessarilyeflectingheviewsoftheDepartmentoftheNavy,theDepartmentofDefense,ortheDepartmentofAgriculture.2ModifiedromLee,J . J . ,S.H.Hutner,andE.C.Bovee,Anl-lustratedGuidetotheProtozoa,"SocietyofProtozoologlsts,TheAllenPress,Lawrence,KS , 985.

SubphylumSarcodinalocomotionby pseudopodiaSuperclassRhizopodeapseudopodia,not

axopodsOrderAmoebidanaked,noshell

FamilyVahlkampfiidaenucleardivisionby promitosis,flagellamaybepresent

GenusNaegleriaFamilyHartmannellidaenucleardivision

notpromitotic,lagellumabsentGenusAcanthamoeba

FamilyEndamoebidaenoflagella,typical-lyndigestivetractGenusEntamoeba

PhylumMicrosporasporesofunicellularorigin,withorwithoutpolarfilamentsClassMicrosporidideaelongated,ovaltotubular

sporesOrderPleistophorididauninucleatespores

FamilyPleistophoridaeinsporogony,vari-ablenumberofsporoblastsform

GenusEncephalitozoonPhylumMyxozoasporesofmulticellularorigin,with

twoormorepolarfilamentsparasitizepoikilo-thermvertebratesorannelids

ClassMyxosporeasporewithoneortwosporo-plasmsandonetosixpolarcapsules,mainlyinishOrderBivalvulidasporesopennwovalvesFamilyMyxosomatidaesporecircularorpyri-

formGenusMyxosoma

PhylumCiliophoraciliaorciliaryorganellesnatleastonestage

SubphylumRhabdophoraciliarycrownaroundcytostome

ClassLitostomateamonokinetidswithan-gentialransverseribbonciliapresentnonlytwoorders

SubclassTrichostomatianooraltoxicystsFamilyBalantidiidaecytostomeandoral

cavityong,bodyciliaholotrichousGenusBalantidium

SubphylumCyrtophoraciliateswithvariedkinetids

ClassOligohymenophoreaSubclassHymenostomatiausuallyholo-

trichousOrderHymenostomatidabodykinetomehaspreoralstructure

FamilyIchthyophthiriidaewatchglass organellenearbuccalcavity

GenusIchthyophthirius


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PhylumApicomplexamotilestagewithapicalcom-plexClassSporozoasidastagewithsimpleesistant

spore(formorphologiccharacteristicsofgenera,seechart, .20),sexualeproduction

OrderEucoccldioridaasexualandsexualphases

FamilyKlossiellidaemonoxenous,micro-gameteswithoutflagella

GenusKlossiellaFamilyHaemogregarinidaeheteroxenous,n

circulatorysystemofverterbrates,ndigestivetractofnvertebrates

GenusHaemogregarinaGenusHepatozoonFamilyEimeriidaemonoxenous,typicallyn

intestinalepithelialcells,sporogonyout-side

GenusEimeriaGenusIsosporaGenusCaryospora(atypical)

FamilyCryptosporidiidaemonoxenous,nmicrovillarborder,sporulationnsideoroutsideofhost,oocystswithfournakedsporozoltes

GenusCryptosporidium

FamilySarcocystidaeheteroxenous,pro-ducingoocystswithtwosporocystsnn-testineofdefinitivehost,asexualstagesnntermediatehost

GenusToxoplasmaGenusCystoisosporaGenusBesnoitiaGenusHammondiaGenusSarcocystisGenusFrenkelia

FamilyGalyptosporidaeheteroxenous,nver-tebratentermediatehost,definitivehostspoikilothermic

GenusCalyptosporaFamilyPlasmodiidaeheteroxenous,zoite

motile,sporozoitesnakedGenusHaemoproteusGenusLeucocytozoonGenusHepatocystisGenusPlasmodium

FamilyBabesiidaeprobablynosexualepro-duction

GenusBabesiaFamilyThelleriidaeerythrocyticstages

smallerthanBabesiidaeGenusTheileria(syn. ,Cytauxzoon)

ProtozoanofundeterminedtaxonomicstatusGenusPneumocystis


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Sarcomastigophora

LelshmaniaDifferentpeciesfelshmania ccurnhekin,mucous embranes,ndisceralrgans.omere foundnan ,og ,ndther ammals ;thersrenrepti les.Lelshmaniap p .reransmit tedo ammal ianosts byandfl iesfo rexample ,utzomyiap p .nd Phieboomuspp . ) .uringheireeding,hero -mastigotetagesntroducedntoheermisfhemamma lndromast igotesrengulfedy histiocytes.Withinistiocytesheyoseheirf lagellum,ivide,ecomemastigotes,ndont inuetoivide.andfl iesecomenfectedyngestinghistiocytesontainingmastigotes. Lelshmaniap p ..uit iplyn acrophagesnkin,mucousmembrants,ndisceralrgans,eadingoulcration,czema,maciation,ndnemia.nvisceraleishmaniasis,hepleensnlargedndhe diagnosisanead eyemonstrat ionfrganismsinp leenulpron e arrowmears . Inissueection,mastigotesrepher ica lovoidan d easure y m.ac hmastigoteonta insrounducleusnd od-shapedinetoplast.nhistologieectionstained ith&E,othtructuresstainlueCP1 .2 ) .n iemsa-sta inedmears,owever,th eucleussedCP1 . 1 ) .TrypanosomaTwofheainpeciesfyclicallyransmittedTrypanosomaoundn ammalsre T .rucel ntl T .cruzl.rucelsransmit tedohe ammal ianos tbysetsel ies.uringeedingfhely ,he etacyclic stagesntroducedntoheirculationfheammal ,wheretividesoroducerypomast igotes. setseflyecomesnfectedyngestingrypomastigoteshatmustndergoyclicdeve lopmentnhelyeforebecomingnfectiveoranother ammal ianost. T , cruzisransmittedoammalsyeduviidugs.Whileugsreeeding,he etacyclicormsdeposi tednugecesnheammal iankin.he metacycl icormntersheloodstreamhroughreaks inhekinndindstsayohecardiac uscle,wheretayransformntonpimast igoteramast igote.Clinicalignsndesionsarygreatlydependingnth eos tndhepec iesf Trypanosoma.orexample ,Tivaxnd Tonglense,hichreonf inedohe p lasma,rimarilyausenemia,hereas rucel,whichccursothnhelasmandntercellulart issuendodyluids,anausenemiasells

Mammal i an skin Engulfedby histiocyte

InfectothercellsmAmastigotesinhistiocyte

Lelshmania

CapflfaryTrypomastigoe.

Multiplicationinmidgut

Metacyclicform Trypanosoma


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degenerative,necrotic,andnflammatorychanges. .cruzicausesmyocarditisandmegacolon.Trypomastigotesarepolymorphicbutmostoftenareelongateandhaveaflagellumwithassociatedun- dulatingmembrane(CP1 . 3 , .4).nGiemsa-stalnedbloodsmears,trypomastigotesof .cruzicanbedif-ferentiatedfromthoseofT.bruceibecausetheformerhavealargerkinetoplastandarecommonlycrescentshaped,whereastrypomastigotesofotherTrypanosomaspecieshaveasmallerkinetoplastandareseldomcrescentshaped. .cruzistheonlymemberofthegenustohaveanamastlgoteformntslifecycle.Collectionsofamastigotesareusuallyfoundinpseudocysts(CP1 . 6 ) . .cruzisusuallyargerthantheLeislimaniaspp.Thekinetoplastof .cruzisarger

andmuchmorebasophilicwhenstainedwithH&EthanthatoftheLeishmaniaspp.(CP1 .6 ) .TrypomastigotesofotherspeciesofTrypanosomacanbefoundnawiderangeofhosts,suchassnakes,frogs,andbirds.T .evansi, .equinum,and .equiperdumaretransmit-tedmechanically,thefirsttwobybitingfliesandthelastonethroughcoitus.Theonlystagefoundnthese,trypanosomessthetrypomastigote.T .evansiaffectsawideangeofhosts.tcausesseriousillness(calledsurra)nhorses,camels,buf-faloes,andoxen.Edemaandemaciationarethemostprominentsigns. .equinumand .equiperdumchieflyaffectequlds.

Trypanosomacruzi


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plate1.Leishmaniaspp.an d Trypanosomaspp.ofanimals: .1 ,Spleenm-rintfromdogwithnumerousamastigotesof.donovanirupturedrommacrophage,X 1500 ,Giemsastain(84-9338). 1.2,DermisofamsterexperimentallyinfectedwithLandcontainingamastigotesvacuolesnmacrophages,X 5 00

1 .3,Peripheralbloodsmearfromnfectedmousecontaining

trypomastigotesof .brucei,X1500 ,Giemsastain(84-9340). 1.4,Peripheralbloodsmearfromexperimentallynfectedmousecontain-ingtrypomastigoteof .cruzi,X 500 ,Giem-sastain(84-9341). 1 .5 ,Heartofdogwithnumerousamastigotes(pseudocyst)of .cruzinmyofibril,X25 (84-5305) . 1 .6 ,Heartofdogwithamastigotesof .cruzi,eachwithlarge,basophilickinetoplast,X1 50 0(84-5306) .


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FlagelltesNumerousgeneraandspeciesofflagellatedproto-zoansarefoundnaninnals.Mostiventheunnenofthentestinalract.Othersiv eonhegillsoffishand sonnentheurogenitaltract.Flagellateshaveasinnple,one-hostifecycle.Th eflagellatedstagetransformsn- toaresistantcyst,whichstransmittedfromoneanimaltoanother.Giardiasthemostcommonlagellateofmammalsandbirds(CP2.1-2 .3) .tstrophozoitesarebinucleateand havefourpairsofflagella.Trophozoitesadheretomicrovilliofepithelialcellsofthesmallntestine.nhistologiesection,tsoftendifficulttodemonstrate

nucleiandflagella,andtheresnoundulatingmem-brane.Pentatrichomonass p p .differfromGiardiabecausetheyhaveasinglenucleus,andoneflagellumsat- tachedothebodywalloformanundulatingmem-brane(CP2.4) .Spironucleus(syn. ,Hexamita)sp . ,anotherflagellate,ssmallerthaneitherGiardiaorPentatrichomonasand lacksanundulatingmembrane(CP2 .5 ) .Trichomonascaviaeoccursnhentestinesofguineapigs.tsflagellaar eeadilyseennstainedfecalsmears(CP2 .6 ) .

y\Cystand/*rophozoiteyefecated

Giardia


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plate2.Flagellatesofanimals:2 .1 ,ntestineofcanarywithnumerousiardiasp . ,X25 0(84-9342). 2.2,Higher

oftrophozoltesofGiardiasp .tointestinalvillusofcanary,X 5 00 2.3,Humanfecalsmearcontain-

trophozolteof.ambliaithtwoX1500 ,ron-hematoxyllnstain 2.4,LumenofsmallntestineofcontainingtrophozoltesofPen-

tatrichomonassp .withargenucleusandun -dulatingflagellum,X1 50 0(84-9345). 2 .5 ,LargentestineofpigeoncontainingtrophozoltesofSpironucleussp .withpyriformshape,X1 50 0(84-9346). 2 .6 ,FecalsmearofguineapigcontainingtrophozoltesofTrichomonascaviaewithundulatingmem-braneandargesinglenucleus,X1100 ,Pro-targolstain(84-9347).


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HistomonasHistomonasmeleagridisaffectspoultry.tsifecyclescomplex.Freetrophozoitespassednfecesarevery delicateandessentiallyhavenoolentransmission.TrophozoiteswithineggsoftheroundwormHeterakisarereadilyinfectivetootherbirds.Usuallyheterakideggsareingestedbyearthworms,andbirdsbecomen-fectedwithboththeoundwormsandtheflagellatesafteringestingsuchearthworms.ntheavianntestine,

thetrophozoitesreleasedromtheoundwormegg andnvadesthececalwall.tosesitsflagellumandbecomesverypleomorphicandamoeboid.toftenmigratestotheiver.H.meleagridiscausesenlarged,atherhemorrhagiccecaandcharacteristic,depressediverlesions.ntissues,trophozoitesoccurnclusters.Theyvarynsize(5-20 i V T i )andshapeandarepoorlystainedwithH&E(CP3 .2 ,3 .5 )butstainbrilliantlywithPAS(CP3 .3 ,3.4,3.6) .

MatureheterakideggcontaininghistomonadFreehistomonaddies

Histomonas


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Colorplate3.Histomonasmeleagridisofchickens:3 .1 ,LiverinfectedwitfiH.me/eagr/d/s(84-9348). 3.2,LiverinfectedwittiH.meleagridisandsfiowinghepaticnecrosisandfaintlystainedtrophozoltes,X 25 0(84-9349). 3.3,CecuminfectedwithH.meleagridisandcontainingtrophozoites(red)throughoutwall, 0,PASstain(84-9350).

3.4,Liverwithtrophozoites(red)throughoutparenchyma,X250 ,PAS stain(84-9353).3.5 ,LiverwithenlargedtrophozoitesofH.meleagridis,X1500(84-9351) .3 .6 ,CecumwithenlargedbrightlystainedtrophozoitesofH. meleagridisnclusterswithinwall,X1500 ,PASstain(84-9352).


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Amoeba e Amoebaencludebligatendacultativearasitesswellsree-l ivingorms.ntamoebasnmportantobligatearasite. Itsifeyclesirect.ngestion causesnfectionndevelopmentfrophozoi tes.heresistantysttagesxcretednheeces.ropho-zoitesesidenheumenfhentestinendayn- vadehentestinalal lndtherxrainestina{organs.isofyicand.nvadensaneoundntheissuesfnimals..istolyicaccursnanut isransmissibleoogs,ats,ndthernimals. n- vadensccursnepti les.heucleusfothas chromatinlaquestheer ipherynd mal ln- dosme. E.istofyticaanauseongest ion,etechialhemorrhages,ndlcersnheargentestine.nanimals,nfectionsenerallyonfinedoheargen- testine,utnantannvadetherrgans..histolyicaangesrom5o0mndiameter"

(CP4 . 1 ,.2)..nvadensCP4 .3 )smaller10-35im).Th ey top lasmf.istofyticasftenighttaining an dranular,hereashey top lasmf.nvadensoftentainsarkerndsgranulartneoleCP4.3 ) .Cys tsfntamoebareoundndontainner ore chromatoidodies.Soilndaterborneree-livingmoebaeuchscan-thamoebandaegleriaanecomearasitic.hey have ifeycleimilarohatfntamoeba.he y enterheostccidentallyhroughheouthros ean dnvadeheentralen/ousystemiahe cribriformlate.heyav eeenoundntherrgans asell.otheneraaveeryistinctiveuclei.he nucleusoesotav eer ipherallaquesfchromatinndhendosmesxtremelyarge(CP4.4-4 .6 ) .aegleriarophozoi tesaylsoave flagellahenree-livingnater.othrganismsan cause eningoencephal i t is .

Entamoeba canthamoeba,Naegleria

10


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Colorplate4.Amoebaeofanimals:4.1,HumanfecalsmearcontainingtrophozoiteofEntamoebahistolyticawithsmallendosmeandchromatinplaquesatperipheryofnucleus,X1500 ,ron-hematoxyllnstain(84-9354). 4.2,ntestineofmonkeywithtrophozoiteof.histolytica,X1 50 0(84-9355) . 4.3,Smallntestineofrattlesnakecontainingtrophozoiteofnvadenswithsmallendosme,X1 50 0(84-9356) . 4.4,Heart

ofdogcontainingtrophozoiteofAcan-ttiamoebasp .withargedarkendosme,X1 50 0(84-9357). 4.5 ,Brainofexperimental-lyinfectedmousecontainingrophozoltesofA.culbertsoniwithargeendosme,X 5 00 (84-9358). 4 .6 ,Brainofexperimentallyn- fectedmonkeycontainingrophozoiteofNaegleriafowleriwithargeendosme,X1 50 0(84-9359).

1 1


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Microspora

Numerousgeneraofmicrosporainfectanimals.Encephalitozoonisperhapsthemostwidelyrecognizedgenus,nfectingmanymammalsandafewbirds.Th e genusGlugeausuallyinfectsfish.Transmissionsthoughttobedirectbycarnivorismorbysporesthatpassfromthebodynurinefthekidneysn- fected,orsporesthatmaybeiberatedfromtissueswhenthehostdies.Whenhesporesngested,thesporontwithinthesporesiberatedandeithers engulfedbymacrophagesorinvadesendothelialcells,wheretundergoesasexualeproductionoformnumeroussporoblasts.Sporoblastsoundupandsecreteathick,esistantsporewall.

Sporesangefrom2to 5 mnength.mmaturesporesareoftensmallerthanmaturespores( CP 5 . 1 ,5.2) .Microsporansporeshavedarkstainingannularmasses,perhapsduetothecoiledilament,whichcanbedemonstratedwithavarietyofstains(CP5 .1 - 5 .3 , .5) .Inaddition,allstagesofmicrosporaarevisiblewithGramstain(CP5 .2 ,5.3) .Maturesporesareacid-fast(CP5 . 5 )andcontainaPAS-positivepolargranule(CP5.4) . Uttrastructurallythesporehasathickoutercoatenclosingafilamentandoneortwonuclei.Oneendofthefilamentsattachedtothesporewallandheotherendscoiledfrom4toover30timesdependingonhespecies.

rxcretionin urine

Microspora


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plate5 .Microsporaofanimals: .1 ,ofgartersnakecontainingmmatureandmaturesporeswithbasopfiilicmasses,X6 30(84-5273). 5 .2,Musclegartersnakewitfimmature(dark)and(lighiter)sporesofmicrospora,X630 ,andHoppstisstjeGramstain

5 .3 ,Kidneyofrabbitwitfisp . ,X1500 ,BrownandtissueGramstain(84-9360). 5 .4 ,Liver

ofovebirdwithPAS-positivepolargranulevisibleneachspore,X1500 ,PASstain(84-9361). 5 . 5 ,Muscleofgartersnakewithdark-bluestainedannularringsanded -stained(acid-fast)maturespores,X630,ZiehlNielsenacid-faststain(84-5276). 5 . 6 ,Bloodvesselngilloffishcontainingnumerousmicrosporawithinhyperplasticendothelialcells,X1000,PASstain(84-9362).

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Myxozoa

Myxozoaarefoundnnumerouscold-bloodedvertebratesandannelids.Theirlifecyclesnotconn-pletelyknown.nfectionbeginswithngestionofspores.Th emotilesporoplasm(amoebula)escapesthroughthesporecoatandpenetratesthegutwall.Viathecirculationtscarriedoextraintestinaltissues.Thesporoplasmundergoesasexualdivisionoformamultinucleatesporont,whichmaturesntospores.Massesofsporesformmyxozoancysts(CP6 . 1 ,6.2).

muscle,gutwall,gills,brain,skin,andtheexcretorysystem.Sporeshavevariedshapes,romovoid(CP6 .3 )toelongate(CP6 . 5 ,6 .6) .Allaremulticellularcontainingtwopolarcapsules(cnidocysts)(CP6 .2 -6 .6 ) ,whichstainintenselybluewithGiemsa.MaturesporesareoftenweaklystainedwithH&E(CP6 .2 )butarestronglyacid-fast(CP6 .4) .

Myxosporidiacauseseveralseriousdiseasesoffish,andheavynfectionscandestroylargenumbersofthem.Th ecystsorinfiltrationsarefoundncartilage,

Maturesporesreleasedfromdecomposingf ishori feces

Myxozoa

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Colorplate6.Myxozoaoffish:6 . 1 ,Musclewitfimultiloculatemyxozoancysts,X 5 84-9363). 6 .2,Musclewithefractivespores,6 30(84-9364). 6 .3 ,SpinalcordcontainingMyxosomacerebraliswithntenselybluepolarcapsules,X1500 ,Giemsastain

6.4,Spinalcordwithacid-fast

maturesporeofM .cerebralis,X 500,Zieh!Nielsenacid-faststain(84-9366) . 6 . 5 ,Gillfilamentwithnumerouselongatespores,X 5 00(84-9367). 6 . 6 ,Gillilamentcontain-ingsporeswithntenselybluepolarcapsules,X 500 ,Giemsastain(84-9368).

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Cilltes

Numerousgeneraofciliatesarefoundnthedigestivetractofdonnesticanimals.Mosthavedirectifecycles.Cystspassednthefecesareingested,andthetrophozoltesreleasednthedigestivetract,whereitundergoeseitherasexualorsexualmultiplication.Trophozoiteshavesurfacecilia.Ciliamaybeofthesamelength(CP7 .2 )orformtufts{CP7.4) .Whenthetrophozoitesarenissue,theciliamaynotbe demonstrable.Balantidiumsp .sacommonci I latenpigs,odents,andprimates.Trophozoiteshaveakidney-shapedmacronucleusandoftenacontractilevacuole(CP7 .2 ,7.3).B.colinormallyoccursnheumenoftheargeintestineandsassociatedwithnochangenmucosa.Occasionallyitnvadesthemucosaandcausesmildtosevereenteritisanddysentery.

Thoughmostciliatesarenonpathogeniccommensals,oftenafterthehostdies,theymovetotheiverviamesentericveinsorintotissueofthentestinaltractandmaybemistakenorpathogens.Theseciliatescommonlyhaveanelongatenucleus,whichsoundncrosssection(CP7.5) . chthyophthiriusspp.arepathogensoffish.Tropho-zoitesofchthyophthiriusspp.maypenetratetheskinandproduce"ich"orwhitespotdisease.Thetropho-zoiteseventuallydevelopacystwall,dropoffthefish,andenterthewater,wheretheyruptureandeleasetrophozoitesthatreinfectotherfish,chthyophthiriusspp.are75 imto mmindiameter,areuniformlyciliated,andhaveacrescent-shapednucleus(CP7.6).

Balantidium chthyophthirius


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Colorplate7.Cilltesofanimals:7.1,LargeintestineofgorillacontainingnumerousBalantidiumsp . ,X25 0(84-9369). 7.2,LargeintestineofgorillacontainingBalantidiumsp .withargemacronucleusanddistinctcilia,X 5 00(84-9370). 7.3,LaminapropriaoflargentestineofgorillacontainingBalan-tidiumsp .withndistinctcilia,prominentbasophllicmacronucleus,andclearcontrac-

tilevacuole,X1000(84-9371). 7.4,Largen- testineofhorsecontainingunidentifiedcillatewithtuftsofcilia,X1000(84-9372).7 .5 ,Largeintestineofhorsecontaininguniden-tifieddilatewithargebasophllicnucleusandprominentcytostome,X1000(84-9373). 7 .6 ,SkinoffishwithIchthyophthiriussp . ,X 1 6 0(84-9374).

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Pneumocystis

ThetaxonomicstatusofPneumocystisisunsettled;someworkersplaceitwiththeprotozoaandotherswiththeyeasts.Thissituationexistsbecausebasicquestionsregardingthebiologyofthisorganism,n- cludingaspectsoftslifecycleandtransmission,are unanswered.Ahypotheticalifecyclespresentedhere asanaidtoIdentificationofstages.ThetermsusedtodescribethesestagesarethoseusedortheApicomplexa.P.cariniisacommonspecies.Th eentireifecycleoc-cursnthelungsofmanyspeciesofmammalsands direct.Maturecystsupture,eleasingeightntracysticbodiesthatdevelopntotrophozoites.Trophozoitescopulateorfusetoformadiploidtrophozoite,whichdevelopsintoaprecyst,ann- termediateformbetweenthetrophozoiteandcystnwhichthenumberofnucleincreasesfromonetoeight.nthemostmaturestageoftheprecyst,eachnucleus,amitochondrion,andsomeadjacentcytoplasmbecomesurroundedbyalimitingmembrane.Aseachofthesebodiesbecomesndependentandathickwallormsaroundthem,theprecystbecomesacystcontainingeightntracysticbodies.

Pneumocystisshouldberegardedasanopportunisticpathogenaffectingthosehumansoranimalswithm-pairedmmunity.Pathologicalchangesareusuallylimitedtothelungs.Ongrossexamination,thelungsareusuallyenlarged,arefirm,anddonotcollapse.Cutsurfacesappeardry,withrregulargray,brown,orpinkareasofconsolidationandsometimescontainiquefiedfoci.Histologicallythelungappearssolidandhighlycellular,withmassivemononuclearinfiltration,predominantlyplasmacells,histiocytes,orym -phocytes.WithH&Estain,acharacteristicfoamy,finegranular,eosinophilicexdatefillsthealveolarspace,butparasitesarepoorlystained(CP8.1-8.3) .PneumocystisstagesarebestdemonstratedwiththeGMSstain(CP8.4 ,8.5) .Somearesphericaland measure2-6 xmndiameter,othersappearcollapsed.Smearsfromthelungsmaycontaincystswithup toeightntracysticbodieswhenstainedwithGiemsa(CP8.6) .mprintsofthelungmayshowcystswithinafoamymatrix.

MeiosisI

g TrophozoiteV-^(diploid)

ynaptonemalcomp lexinnucleus

\ C D ,1 ^ Copulat ion ( OTrophozoite\ y(haploid)

o)(o)o)(oxRupturedcyst Celldelimitation8Intracysticbodies

Pneumocystis

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A

V i

Colorplate8.Pneumocystissp .ofmam-mals:8.1,Lungofhorsewithseverepneu-mocystosis,X60(84-9375).8.2,Lungofhorseathighermagnificat ionshowingalveolifilledwithfoamyeoslnophil icmaterial,X25 0(84-9376). 8.3,Lungofhorseatveryhighmagnificat ionshowingeoslnophil icmaterial,X1500(84-9377). 8.4,Lungofhorsewith

numerousorganismsnalveoli,X250,Gomorimethanamlnesilverstain(GMS)(84-5303).8.5,Lungofhorsewithnumerousdarkly stainedovoidorganisms,X1500,GMSstain(84-5304). 8.6,Lungsmearofra tcontaining Pneumocystisystswithntracyst icorganisms,X1500,Glemsastain(84-9378).

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Apicomplexa Sporocysts: 0Sporozoites: 4

CoccidianhegeneraCryptosporidium,Eimeria,sospora,Sarcocystis,andToxoplasmaarethemostecononnicallynnportantgroupofprotozoansndonnesticaninnalsntheUnitedStates.Historicallythestructureofthesporulatedoocyst,especiallythenumberofsporocystsandsporozoites,wasusedasamajorcharacteristictodifferentiategeneraofcoccidia.Theaccompanyingchartprovidesacomparativeguidetohemorphologyofsporulatedoocystsamongtheseandothergeneraofcoccidia.Eimeria OverathousandspeciesofEimeriaareknov/nhatprimarilynfectcellsiningthentestineofdomesticandwildmammalsandbirds(CP9-17) .Th eifecycleforeachspeciesshostspecificanddirect.Unsporulatedoocysts(BW1 .1 )areshednecesandsporulate(BW1.2)ntheenvironmenttobecomenfectious.Followingngestion,sporozoites(BW1.3 ) ,arereleased(excyst)nthentestine.AsporozoiteInvadesanepithelialcellandoundsuptoformatrophozoite(BW1.4),whichundergoesnucleardivisionnitiatingacycleofasexualmultiplication(merogony,schizogony)(BW1 .5 , .6).Merozoitesreleasedromasexualstageseventuallyformsexualstages(male microgamete,female macrogamete){BW1.7 , .8),whichunitetoformoocysts.Unsporulatedoocystsaresurroundedbyadistinctwallandcontainagranularcytoplasmicmasswithinwhichisndistinctnuclearmaterial(BW1 .1 ,CP10 . 6 ) .Sporulatedoocystscontainfoursporocysts,eachcon-tainingwosporozoites(BW1.2) .SomespeciesofEimeriacanbespeciatedbydifferencesnoocyststructuresuchassizeandshape,presenceorabsenceofresiduum,polargranules,micropyle,andcapcover-in ghemicropyle.Th esporozoitesthemotile,n-fectiousstagethatpenetratesthehostcellandsiden-tifiedbyitsbananashape,singlenucleus,efractile(paranuclear)bodies,andPAS-positivegranules(B\A/1.3).Thetrophozoitestheintraceiluiar,oundeduninucleatestagethatdevelopsfromthesporozoiteormerozoite(BW1.4,CP13 .4 ) .Asexualstageseferredtoasschizontsormerontsdevelopfromsporozoitesormerozoites,andmmaturestagescontainfrom2toover100,000nuclei(BW1 ,CP11 - 1 4 , 6 , 7) .Each nucleusbecomesncorporatedntoamerozoite,amotilenfectiousstagestructurallysimilartothesporozoite(BW1,CP9 , 0, 2, 4, 6 ). Sexualstagesdentifiedasmacrogametes(female)areuninucleateandcontainperipheralPAS-positivegranules(BW1,CP10 , 2-15 ,7) .Th emmaturemalestage(microgamont,microgametocyte)smultinucleate(CP15 .2 , 7.4).Wheneachnucleusbecomesncor-

Genus: Cryptosporidium Tyzzeria CaryosporaSporocysts: 2 4 4 Sporozoites: 8 8 16

Genus: Besnoitia CalyptosporaCystoisospora EimeriaFrenkeiiaHammondiaIsosporaSarcocystisToxoplasma

Wenyonella

Stylizedllustrationofsporulatedoocystsepresentativeofcoccidiangenera.Beloweachoocyststhenameofagenusinwhichhatmorphologicformsfound.Aboveeachoocystisthenumberofsporocystsandporozoitesfoundneachoocystofthatgenus.

poratedntoaspermlikebiflagellatestructure(microgamete,BW1.8) ,themicrogamontsmature(CP10 . 5 , 4.3).Th eunsporulatedoocystsormedromthemacrogameteafter tsfertilizedbyamicrogamete(CP10 . 6 , 7.3, 7.6) .CoccidiosisduetoEimeriasmostcommonnyounganimals.LesionscharacteristicofEimerianfectionare locatedatthesiteofparasitism.Destructionofn- fectedcellsandsurroundingissuecanesultnnecrosisandhemorrhage(CP9, 0)andncellularn- filtrationwitharchitecturalchange(CPU, 3,4, 6 ).Eimeria Excretion


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Blackandwhiteplate1.Elmerianifecycle.Stagesnmammaliancellculture,ive,un -stained;eitherNomarskinterferencemicroscopy(NI)orphasecontrastmicroscopy(PC): .1 ,UnsporulatedoocystofEimeriamagnawithoocystwallaroundgranularsporontcontainingcentralnucleararea,NI,X2200. 1 .2,SporulatedoocystofE .magnawithoocystwallaroundgranularresiduumandoursporocysts,eachcontain-in gwosporozoitesandeachsporozoitewithcentralnucleusanddistinctposteriorretrac-tilebody(arrow),NI,X1700. 1.3,ntra-cellularsporozoiteof .arimerensisadjacenttohostcellnucleussurroundedby clearparasitophorousvacuole,PC ,X 200. 1 .4,

Intracellulartrophozoiteofzuernii(arrow)withargenucleusanddarkeccentricnucleolus,PC ,X 200. 1 .5 ,mmaturemerontofE.zuerniicontainingnumerousnuclei(ar-row),eachwithdistinctnucleolus,PC ,X 1600 . .6 ,Maturemerontof.magnaon- tainingnumerousmerozoites,PC ,X 1050 . 1 .7,MaturemacrogameteofEmagnainparasitophorousvacuolewithnumerousgranules(wall-formingbodies)throughoutcytoplasmanddistinctnucleuswithdarkec- centricnucleolus,PC ,X 100 . 1 .8,Microgametesof.magnaeleasedfrommicrogamont,eachmicrogametewithspindle-shapedbody(arrow)andtwoflagella,PC ,X2200.

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ColorplateQ.Eimeriaspp.ofchickens:9.1,DigestivetractstiowinggrosslesionsofE.necatrixnsmallntestine(left)andE.enellainceca(right)(84-9379). 9.2,Cecashowingexperimentalnfectionwithenellandnecrosisandhemorrhage(84-9380). 9.3,Smallntestinecontainingexperimentaln- fectionwithEimeriaandshowing .necatrixwithdistentionandmultifocalhemorrhage(bottom),acervulinawithmoderateedema

andnohemorrhage(middle),anduninfected(top)(84-9381). 9.4,Cecum(a sn9.2)show-ingtissuecrosssectionof .enellanfec-tionesultingnargececalcorewithhemor-rhageandnecrosis,X5(84-9382). 9.5,Highermagnificationofcecumshowinguninfectedmuscularis(bottom),numerousschizontsofenellansubmucosa(middle),andnecroticdebris( top) ,X1 6 0(84-9383). 9.6,Highermagnificationof9.5,X 25 0(84-9384).

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10.5Colorplate Q.Eimerianecatrixofchickens:10.1,Crosssectionofntestinestiowingex- tensivetiemorrtiageandnecrosis,X7 (84-9385). 10.2,Higiiermagnificationshow-ingnumerousschizonts,hemorrhage,andnecrosisnsubmucosa,X160(84-9386). 10.3,Matureschizontscontainingmerozoites,X

10.61000(84-9387).0.4,Macrogametes with eosinophil icperipheralgranules,X1000(84-9388). 10.5,Microgamontscontaining microgametes,X1000(84-9389). 10.6,Unsporulatedoocystsnumen,X1000(84-9390).

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-..--.. ,.. ' ***-' '1'. 'V^^t^J^X-P* v-'.

. .:,-.>*;*>:'C*--.'*'.*" " "-A^ '-^o*,

, - i^V. :'^-

11 .5 plate 1 .E/mer/aspp.ofbirds: 1 . 1 ,

idneyofgoosewithgamontsntubularcells,X1 6 0(84-9391). 11 .2,KidneygoosewithhighermagnificationofX6 30(84-9395). 11 .3 ,ntestineofcranechickwithE.eichenowi

oocysts(upperleft)andsmallbasophlllcnmacrophagesInbloodvessels,25 0(84-5254). 11 .4 ,Pancreasofwhooping

cranewithgranulomacontainingE.reichenowi,X40 (84-9392). 1 1 . 5 ,Highermagnificationof11 . 4showingwotofournucleateschizonts,X1000(84-9393). 1 1 . 6 ,SmallntestineofswanwithargevacuolatedschizontofEimeriasp .surroundedby vacuoleencapsulatedby hosttissue,X1 6 0(84-9394).

i ^ -: ;^ i

' ^'M-'^)a^

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12.5 12.6 Colorplate12.Eimeriaspp.ofbovines:12 .1 ,SmallntestineinfectedwithE,bovisX1 6 0(84-9396). 12.2,Villusnsmalln- testineandtwoschizontsof .boviscontain-ingessmatureschizontoneftwithinhostcellwithhypertrophienucleus,X 6 0(84-9397). 12.3,Epitheliumoflargentestinewithnumeroussecondgenerationschizontsandgamontscharacteristicofzuernii,

6 30(84-9398). 12.4,Villusnsmallntestinewithoocyst(eosinophilic)andmmaturemicrogamontofalabamensisnaminapropria,X25 0(84-9399). 12.5 ,Highmagnificationofimmaturemicrogamontofalabamensisshowingwhirlsofdensenuclei,X6 30(84-9400). 12 .6 ,Largeintestinewithnumerousmacrogametesofalabamensis,X25 0(84-9401).

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13.6plate 3.Eimeriaspp .ofsheep:13.1,ntestinewithwhitepo lypo idareasof(oocystpatches)du etoE .ovina 13.2,TissuecrosssectionofX8(84-9409). 13.3,Highermagnifica-ofpolypshowingnumerouseosinophi l icbasophi l icmicrogamonts,dfewoocystswithinepithel ia lcells,X630 13.4,Polyp withnumeroussmall

merontsbetweenhostcellnucleusan dbrush border,X630 (84-9411). 13.5,Smal lntestine withmmatureschizontofEimeriasp .nlacteal,X25 0(84-9413). 13.6,Smallntestinecontainingargemmatureschizontof Eimeriawithcompartmentsformedbyn-foldingofperipheralnuclearayer,X25 0(84-9414).

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C?ia?ti^'*--14.3 ^ B

X^ ^ B ^ ^HHp. ^ ^ ^ ^ ^ B ^ H^1

14.4

14.5 Colorplate A.Eimeriaspp .ofsheepandgoats:14.1,SmallIntest ineofsheepwithwhirlsof elongatemerozolteswithinmatureschizontofEimeriasp.,X1500(84-9415). 14.2,LargeImmatureschizontnaminapro-prlaofgoatwithnumerouseoslnophll lc macrogametesandyoungoocysts n epithe-lium (speciesunknown),X160(84-9416).14.3,Intestineofgoatwithtwomassesofsperm-likemicrogametesandfreemicrogametes n hostcellvacuole,X1500(84-9417).14.4,

14.6 Mesenterlcymphnodeof goatwithcapsularafferentymphat icvesselcontainingargem-matureschizontofEimeriasp.,X25 0(84-9412).14.5,Mesentericymphnodeofgoatwithcapsularafferentymphat ic vesselcontainingargeschizontofEimeriasp .withnucleiarrangedncircularblastophores,X 25 0(84-9418).14.6,Gallbladderofgoatwithnumeroussmal lschizontsofEimeriasp .nlaminapropria,X630 (84-9419).

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5 .3 15.4

\ 'A*---

V.-.r,15.5Colorplate5.Eimeriaspp.ofhorses,deer,andgoats: 5 . 1 ,SmallntestineofhorsewithmacrogamontofE.euckartiInaminapro-prla,X6 30 (84-5248). 15 . 2 ,Smallntestineofhorsewithmicrogamontof .euckartinlaminapropria,X400 (84-5251). 15 . 3 ,Smallintestineofhorsewithdevelopingoocystnlaminapropria,X400(84-5250). 15 . 4 ,Mesentericlymphvesselofre ddeerwith

15 . 6 numerousargeschizontsofEimeriasp . ,X6 0(84-9402).5 . 5 ,LymphnodeofdeerwithnumerousschizontsofEimeria,X6 0(84-9403).5 . 6 ,Liverofgoat(Capraibex)withmacrogametescontainingcentralnucleusandperipheralgranulesandwithoocystscontainingcentralnucleusandr- regularwallofEimeriasp . ,X6 30 (84-9404).

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16.6plate16.Eimeriaspp.ofwallabiessnakes: 6 . 1 ,SmallntestineofwallabynumerousargeschizontsofEimeriasp . ,

6 0(84-9405). 16 . 2 ,Smallntestineofathighermagnificationofschizont

Eimeriasp .showinghypertrophie)hostsurroundingvacuolecontainingmaturewithnumerousmerozoites,X25 0 6 .3 ,Smallntestineofwallabywith

hypertrophiedhostcellnucleustorightofschizont,X6 30(84-9407). 6 .4 ,BileductofracerwithstagesofEimeriasp .nepi-thelium,X25 0(84-9429). 6 . 5 ,BileductepitheliumofracerwithEimeriap .,X400 (84-9430). 6 . 6 ,Bileductepitheliumofracerwithschizont(center),macrogamete(farleft),andtrophozolte(right),X 00 0(84-9431).

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17 .5 17.6ColorplateM.Eimeriaspp.ofrabbitsandmink: 7.1 ,LiverofrabbitwitfigrosslydilatedbileductduetoEstiedae,X25 (84-5307). 17.2,HigfiermagnificationofepitheliumofbileductwithnumerousmacrogamontsofEstiedae,X25 0(84-5308). 17.3 ,Highermagnificationofepitheliumofbileductwithelongateoocyst(right)andtwomacrogametes(left),X1000(84-9423). 17.4,High

magnificationofepitheliumofbileductwithmultinucleatemicrogamontsofEstiedae,X 1000(84-5310). 17 .5 ,LiverofminkwithgrosslydilatedbileductduetoEhiepei,X 1 5(84-9424). 17 . 6 ,Highermagnificationofepitheliumofbileductwithschizont(bottomleft),microgamont(bottomright),andthreeoocystssurroundedbynflammatoryceils(top),X1000(84-9425).

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IsosporaIsosporanspeciesarecoccidianparasitessimilarn generalifecycleandstructuretoeimerianspeciesbutdifferingnnostobviouslyntheoocyststructure(seechart, .20).Historicallyallsoporanswereconsideredtohaveifecyclesdenticaltothoseofeimerians,n- fectingonlythedigestivetractofasinglehostspecies,andwereclassifiedasIsosporaspp.tsnowknownthatcertainsosporanscanproduceencystedasexualstagesnextraintestinaltissuesofthehost,andtheyhavebeeneferredtoby sonneauthorsasCystoi-sospora spp.

Isosporaspp.arefoundprinnarilyncarnivores,passerifornnbirds,amphibians,eptiles,odents,humans,otherprimates,andswine(CP18) .sosporaoocystsfoundnecesofcattle,sheep,chickens,and turkeyshavebeenaccidentallyingestedfromotherhosts./ .suisofswinellustratestheifecycleandpatho-genicityofthisgenus.Oocystsareunsporulatedwhenshednecesandsporulatenheenvironmenttobecomenfectious,asdothoseofEimeria.Followingingestionofsporulatedoocysts,sporozoitesarere-leasednthentestine,wheretheyparasitizeepithelialcells.Sporozoitesdividebyendodyogenytoformtwoprogenies(CP18 .1 ) .Afteraseriesofsuchdivisions

ithinhesamehostcell,merozoitesmaybeeleased.Merozoitesundergoasecondtypeofasexualdivisionschizogony),nwhichnumerousnucleidevelopandmanymerozoitesareformed(CP18 .2 , 8.3).Followingsexualmultiplication,merozoitestransformnto(CP18.4) ,whi-chnurnproduceoocysts.

dueto .suis,characteristicallyfoundnpiglets,canbeperacuteandelatedtoexten-multiplicationofasexualstages.Diagnosisofnfectionssfacilitatedbyexaminingmucosalforsuchasexualstages.Oocystshavenotyetandthereforearenotpresentnthefeces..causesvMlousatrophy,necroticenteritis,orboth.visiblefibrinonecroticmembranesmaybe nhesmallntestine.

heifecycleofcertainspeciesofsospora(thosetoasCystoisospora)mayinvolveatransporthost.Thishostbecomesnfectedbyn- sporulatedoocystsandthenharborsacystcontainingasinglesporozoite(CP19 .3 )variousorgans.Whenthishostseatenbythefinalthesporozoitenitiateshentestinalcycle 9.4, 9.5).tsnotpathogenicnthetransportbutmildlypathogenicndefinitivehosts.

Monozoiccysiinextraintestinal tissue

Optionalfo rCystoisosporaonly Ingestion 'ngestionSporozoites ^L^tr'^"'"Excystation

Isospora

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18.4|| _ - m t ' ^ ^ H1m^^^^^^^H^ ^91^ B i. -:-:^#-_^. 18.6plate8.lsosporaspp.ofpigsand 8.1,Smallntestineofigwith merontsof,suis,X6 30(84-9620). Smallntestineof igwithtypeIIof .suis,X6 30(84-9619).Smearofsmallntestineof igwithandmerozoitesof .suis,X630 ,Diff- Quikstain(84-9621).8.4,Smallntestineofp igwithmacrogametesandmicrogamontsof/.suis,X6 30(84-9622).8.5,Skeletalmuscleofbaboonwithnumeroussporulatedoocystsof .papionis,X6 30(84-9581).8.6,Skeletalmuscleofbaboonwithsporulatedoocystsof/.papionis,X6 30(84-9582).2


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19.4

plateA9.lsosporaspp.and

spp.ofmammals: 9.1,SmallofcatwithntraepitlielialmerontsC .rivoltacontainingmerozoites,X 500 ,stain(84-9497). 19.2,n-

ofcatwithmultinucleatebasophilicanduninucleateeosinophilicofC .elisnepithelium,X

(84-9498). 19.3,MesentericymphnodemousewithsmearofmonozoiccystofC .showingclearwhitespacesurrounding

thickdarklystainedwallenclosing singlesporozoite,X1500 ,PASstain(84-9499). 19.4,SmallntestineofdogwithseveralmaturemerontsofC .ohioensisnepithelium,X6 30 (84-9500). 19.5 ,Smallntestineofdogwithvariousasexualandsexualstagesof .neorivolta,X 00 0(84-9501). 19.6 ,Smalln- testineofdogwithdevelopmentalstagesofIsosporasp .extendingntosubmucosa,X 160(84-9502) .


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CaryosporaCoccldiaofthegenusCaryosporaarefoundprinnarilyinbirdsandsnakes.Membersofthegenuswereoncethoughttoinfectasinglehostspecies.RecentstudiesshowthatspeciesofCaryosporahavetwo-hostifecycles.nwhichthehostshaveapredator-preyrelation-ship.Thereareowl-mouseandsnake-mousecycles.Unsporulatedoocystsareshednthefecesofthepredatoryordefinitivehost(birdsandeptiles).Sporulatedoocystscontainasinglesporocystwitheightsporozoites.ngestionofsporulatedoocystsby thedefinitivehostesultsnmerogony,gamogony,fer-tilization,andformationofoocystsnthentestinal

epithelium(CP20 .1 ,20.2).ngestionofsporulatedoocystsbythe re yorintermediatehost(rodents)resultsnextraintestinalmerogony,gamogony,fertiliza-tion,sporulation,andformationofacaryocysttypical-lycontainingasinglesporozoitenthetongue,der-mis,andhypodermis(CP20 .3 ,20.6) .ngestionofthepreywhosetissuescontaincaryocystsresultsnmerogony(twogenerations),gamogony,andoocystformationntheintestineofthepredator.LittlesknownofthepathogenicltyofCaryospora.Ex-perimentallyInfectedmicedevelopfacialedemaandsomedie.Clinicalllnesshasnotbeeneportedfordefinitivehosts.

Secondgenerat ion Macrogamont

Firstgeneration MicrogamontX.

Rodentsecondary host) Stagesin cheekCaryospora

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20.5 20.6 Colorplate20.Caryosporabigeneticaofsnakesandmice:20.1 ,Smallntestineofat -tlesnakewithnumerousschizontsnepithelium,X25 0(84-9516) . 20.2,Highermagnificationofattlesnakentestinewithschizonts,X1000(84-9517). 20.3,Skinofmousewithnumeroussporulatedoocystswithinclearvacuolesofhostcellssur-roundingdenselystainedhairshaft,X25 0

(84-9518). 20.4,Skinofmousewithsporulatedoocystscontainingsporozoites,X 1 5 00(84-9519). 20.5 ,Tongueofmousecon-tainingmicrogametocyte(left)andmacro-gamete(middle)nhostcellwithnucleuson right,X1 5 00(84-9520).20 .6 ,Tongueofmousewithcaryocystcontainingsinglesporozoitewithinhostcellnaminapropria,X1 50 0(84-9521) .

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CryptspondiumCoccidiaofthegenusCryptosporidiumarefoundnmammals,birds,fish,andeptiles.Historically,numerousspeciesofCryptosporidiumwereeachthoughttonfectasinglehostspecies,butecentstudiesshowthatansolateofCryptosporidiumfromonemammalianhostcannfectseveralothermam-malianhostspecies.Transmissionsdirect.Unusuallysmall(ca.5fivn)sporulatedorunsporulatedoocystsare shednhefeces(CP22) .Onngestionorinhalationofsporulatedoocysts,sporozoitesareeleasedandnfecttheepitheliumInhedigestiveorrespiratorytract.AlthoughasexualandsexualstagesofCryptosporidiumaremorphologicallysimilartothoseofothercoccidia,theypossesssomeuniquedistinguishingcharacter-istics.Allstagesaresmallca . -6 mndiameter)and

arelocatedatthemicrovillarsurfaceofepithelialcells(BW2).Whenviewedwithightmicroscopy,thesestagesappearasdots(CP21) .Merontscontainonlyfourtoeightmerozoites.Someoocystssporulatensituandcontainfoursporozoites.Cryptosporidiumstypicallyfoundnneonataloryounganimals.Diseasesnotalwayspresent.Cryptospori-dium,however,hasbeenassociatedwithclinicalenteritis(CP21 .3 )nseveralhosts,ncludingmanand domesticanimals,andwithespiratoryllnessnman anddomesticbirds.Diagnosishasbeenecentlyfacilitatedbydentifyingoocystsnhefeceswithphase-contrastmicroscopyandseveralstainingproceduresormerlyusedoracid-fastbacteria.

FirstgenerationmerontsTrophozoite / ^ - lilMerozoite

Secondgenerationmeronts

Merozoite

Ingestion Sporulated Unsporulated MicrogametocyteWocystocystExitfrombody

utoinfection

Macrogametocyte

Cryptosporidium

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21 .2

^iFJ

21 .4

plate2^.Cryptosporidiumspp.of21 . 1 ,Smallntestineofcalfwithwithinsurfaceofepitheliumand

malldenselystainedstages(left)andargerocyst(right),X1500(84-9433). 21 .2 ,tomachofsnakewithnumerousstages

withingastricepithelium,X1 5 00(84-9434) .21 .3 ,Hypertrophledstomachofblackra tsnakewithcryptosporldiosls. 21 .4 ,

21 .6 Smallntestineofcalfcontainingtworedoocystsandnumerousdevelopingstageswithinepithelium-withacid-faststaindemonstratingpositivityofmatureoocystsbutnotofotherstages,X1500(84-9435).21 . 5 ,Trachalepitheliumofturkeywithnumerousstages,X6 30(84-9436). 21 .6 ,Kidneytubulesoffinchwithnumerousstageswithinumenandntubularepithelialcells,X6 30(84-9437).

m


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22.3 22.4 Colorplate22.Cryptosporidiumspp.ofcalves:22.1 ,Fecalsmearwithoocystsstainededandyeastsgreen,X1500 ,acid-faststain(84-9432). 22.2,Fecalsmearwithoocystsstainedblue,X750,Giemsastain.22.3,Fecalloatwithunstainedoocysts

suspendednwaterandviewedwithbrightfieldmicroscopy,X 500 . 22.4,Fecalloatwithunstainedoocystssuspendednsugarsolutionandviewedwithphase-contrastmicroscopy,X1500 .

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Blackandwhiteplate2.ElectronmicrographsofCryptosporidium sp .ofsheep. Stagesnepithelium ofsmalln-test ineofweel


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SarcocystisSarcocystissagenusofcyst-formingcoccidiawithanobligatorytwo-hostifecycle.CystsarefoundprimarilyInmusclesofwildanddomesticherbivores.Carnivoresthatpreyonherbivorehostsbecomeinfectedandserveasdefinitivehostswhenzoiteseleasedbydigestionofmaturecystsnvadethentestinalepitheliumand developdirectlyntogamonts.Fertilizationsfollowedbyformationofoocysts,whichsporulatewithinthen- testine(CP23 .1 ,23.2)andareshedasnfectiveoocystsorsporocysts(CP23 .3 )nthefecesofthecarnivore.On Ingestionofoocystsorsporocystsbysusceptibleher-bivorousmammalsorbirds,sporozoitesarereleased(ex-cyst)ntheintestine.Theymigratetoarterialvessels,wheretheydevelopntomeronts(CP23.4 ,25.1) . MerozoltesiberatedfromthesemerontsInitiateasec-ondgenerationofmerontsncapillariesthroughoutthebody(CP23 . 5 ,BW3).Merozoltesiberatedromsecondgenerationmerontsentermononucleatecellsfoundnthecirculationandundergoendodyogenywithinthecytoplasmofthesecells(CP23 .6 ) .Merozoltesfromthecirculationentertheheartandskeletalmusclecellsand theneuraltissue,wheretheydevelopntommaturenoninfectivesarcocyststhatcontainunicellularmetrocytes{CP24.4) .Metrocytesproducebradyzoitesthatareinfectiveforthepredatoranimalandwhosepresencecharacterizesamaturesarcocyst(CP24 .5 ,24.6,25.3-25.6) .Sarcocystsofsomespeciesemainmicroscopic(CP24 . 5 ,24.6),whereasothersbecomevisi-bletotheunaidedeye(CP26 . 5 ,26.6) .

Sarcocystis

SomespeciesofSarcocystisarepathogenictotheherbivoreintermediatehost.Acuteesionscharacter-izedbyhemorrhage,edema,andnecrosisare associatedwiththematurationofsecondenerationmeronts.Macroscopicesionsobservedpostmortemmayincludegeneralizedserousatrophyoffat,ex- cessiveyellowishfluidnallbodycavities,wateryblood,petechialhemorrhagentheheartandpericar-dium,serosaofthegastrointestinalractandurinarybladder,edemaandhemorrhageoflymphnodes,and alternatepaleanddarkstripingormottlingofskeletalmuscles.Microscopically,hemorrhagemaybeseennallorgans,andmononuclearcellnfiltrationntothepehvascularandntestinaltissuesoftheheart,skeletalmuscles,ung,iver,andkidneymaybemildtosevere(CP24.1-24.3) .Regenerativechangesaremostoftenassociatedwiththemyocardium.Chronicesionscharacterizedbymuscleatrophyandmyositisare associatedwithmaturesarcocysts.Specificmacroscopicesionsmaynotalwaysbeseenpostmortem.Microscopicesionsmayncludemyositisandmyocarditis.Mostdefinitivehostsar eclinicallyunaffectedbySarcocystisnfection.


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hr.H -%1 b

23.2

'1 #

% 23.4

23.6 plate23.Sarcocystis cruzi (syn.,S .ofcaninesandbovines:23.1,Intestineofdogwitfinumerous oocystsnsubepitf iellum,X630 23.2,Smallntestineofdogwitfioocystscontainingsporozoitesyellow cytoplasm andredpolysac-andgreennucleoplasm,X1000,polychrome stain(84-9504).23.3,ofdogcontainingsporocystsofS .eachwithfoursporozoitesand

granularresiduum,X1500,unstained(84-9505).23.4,Renalarteryofcalfcontainingthreedevelopingmeronts,eachwith numerousnucleioccludingumenofvessel,X630 (84-9515).23.5,RenalglomerulusofcalfcontainingthreeIntravascularmeronts,tw oimmature (left)andonematurewith merozoltes(right),X1500(84-9507).23.6,Peripheralbloodsmearofcalfwithmononucleatehostcellcontainingbinucleatemerozoite.X1500,Giemsastain(84-9508).

4 J


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24.6 plate2A.Sarcocystiscruzi {syn., .

ofbovines:24.1 ,Placentalaminaofcowwithnumerousfreeandn- merozoitesandmmaturemerontsareaofnecrosis,X6 30(84-9522).24.2,ofcalfwittihemorrhageofmyocardium24.3,ntestineofcalfwithhemor-nserosa(left)andmucosa(right)

(84-9524).24.4,Heartofcalfwithmmaturesarcocystcontainingglobularimmaturemetrocytes,X6 30(84-9525).24.5 ,Tongueofcalfwithnumerousbasophilic,mature,n- tramuscular,andmicroscopicsarcocysts,X 25 0(84-9526).24.6 ,Highermagnificationofmaturesarcocystswithongitudinalan d crosssectionsofsarcocysts,X25 0(84-9527).

2


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1 '**i - < ^ " - * S > ^ , ^?(

^

25 . 5 25 .6 Colorplate25.Sarcocystis spp .ofbovines:25.1 ,Mesentericartery withmult lnucleatedfirstgenerationmerontofS .hirsuta(syn.,S .bovifelis)protrudingntoumen,X6 30 (84-9509).25.2,Myocardium withsecondgenerationmerontofS .hirsutasurroundedbynflammatorycells,X630 (84-9510).25.3,Esophagealmuscle withthick-walledsar-cocystofS .hirsuta,X6 30 (84-9511).25.4,

EsophagealmusclecontainingsarcocystofS .hirsutawithPAS-negativewallan dPAS-positive granulesnzoites,X630,PASHstain(84-9512).25.5 ,Tonguemusclewiththree thicl


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26 . 6 Colorplate26.Sarcocystis spp .ofvarious animals:26.1 ,Smallntestineofratt lesnake;noteacid-fastnessofmaturesporozoltes,X 630,acid-faststain(84-9528).26.2,Lungofpenguinwithsinuousschlzont n en-dotfiellum ofcapillary,X1000(84-5253).26.3,

Muscleofsealcontainingmaturesarcocyst,X1000(84-9578).26.4,Muscleofca tcontain-ingsarcocyst,X630 (84-9579).26.5 ,Tracheaofsheepcontainingargesarcocysts(84-9527).26.6 ,Muscleofbirdcontaininglargesarcocysts(84-9530).


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Blackandwhiteplate3.ElectronmicrographofSarcocystisofsheep. MaturesecondgenerationschlzontofS.enellawithseveralmerozoltes(M )nglomerularcapillaryndwithschlzontndirectcontactwithhostellcytoplasm,withoutaparasitophorous

vacuole,X12,300. E,endothelialcell;L,lumenofglomerularcapillary;P,podocyte;U ,urinaryspace. Diagnostically,tsimpor-tanttorecognizethatSarcocystisschizontsar edistinguishedfromothercoccidiabylackofaparasitophorousvacuole.

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FrenkeliBCoccldiaofthegenusFrenkeHa av eanobligatorytwo-hostlifecycleinvolvingarodentntermediatehost(p rey)andaraptorialbirddefinitivehost(predator).Ex-ceptfornnarkedmorphologicdifferencesnthecyststage,thelifecyclesnearlydenticaltothatoftheSarcocystiss p p . Rodentsareinfectedbyingestionofsporulatedoocysts(CP27 .1 )orsporocysts.Merogonyoccursntherodentiver(CP27.2) ,andtissuecystsarefoundnthecentralnervoussystem(CP27.3-27.6) .Maturetissuecystscanbemacroscopic.Theyaremultilobulatedand surroundedbyathinwall,withmanythousandsof

slenderbradyzoites,whicharenfectioustothedefinitivehost.AfterIngestion,bradyzoitesenterthen-testinalcellsandormgametes,whichdevelopntooocystsafterfertilization.Oocystssporulatensituand areshednthefeces.Lesionsareprimarilyassociatedwithdevelopmentoffirstgenerationmerontsntheiverofodents.Characteristicesionsncludehepaticnecrosisand perlvascularcellularinfiltrationnnumerousorgans.Growthoftissuecystsnhecentralnervoussystemmayresultnpressurenecrosisofsurroundingneuraltissue,witharesultantesorptivenflammatoryresponse.

Frenkelia

46


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plate27.Frenkeliamicrotiofbirdsdrodents:27.1,FecesofEuropeanbuzzardbuteo)withoocyststagesofF .X630,unstained(84-9438).27.2,Liverfshort-tailedvole(Microtusagrestis)con-merontofF .microtiwithperipheralX1000,stainunknown(84-9439).

27.6 27.3,Brainofvole{M .modestus)natural lyn-fectedwithnumerousobulatedcysts,X 25 (84-9440).27.4,Highermagnif icationof27.3,X100(84-9441).27.5,Highermagnif icationofcyst,X 250,PASHstain(84-9442).27.6,Highermagnif icationofbradyzoitesncyst,X1500,PASHstain(84-9443).

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BesnoitiaCoccidiaofthegenusBesnoitia av ebeenoundprinnarilynbovldsnAfrica,Asia,andsouthernEurope ,equidsnAfricaandMexico,reindeerandcaribounNorthAmerica,odentsandopossunnsntheUnitedStates,andizardsandopossunnsnCentralAmerica.Allheseanimalsarenfectedwiththecyststageandthereforeappeartobeintermediatehosts.However,fewlifecyclesareknown.CatshavebeendefinitivehostsorthreespeciesofBesnoitia.Catsshedunsporulatedoocystsnthefeces.Oocystssporulate,resemblingthoseofsospora(seechart, .20).Onn-gestionofsporulatedoocystsbyasusceptiblen- termediatehost,sporozoitesexcystandmultiplyasex-uallyintoclustersoffusiformcells(tachyzoites)thatinitiatecystdevelopmentnconnectivetissue(CP28 .3 ,28.5,28.6,29.1-29.3).Thesecystsarespherical,white,glistening,andthickwalled.TheycontainmanythousandsofPAS-positivebradyzoitesandgrowtoseveralmillimetersndiameter(CP28.3 ,29.4).Th ewalls often 0vothickorthickerandmaycontainseveralhostcellnuclei(CP28 .6 ,29.2,29.6) .Cystsdevelopncon=

nectivetissuethroughoutthebodybutespeciallyntheskin,conjunctiva,mesentery,andscrotum.Onngestionofcystsby thedefinitivehost,bradyzoitesarereleasedandnitiatemerogonyandhengametogonyandoocystformationnthesmallntestine(CP28 ,1 ,28.2). Acuteesionsofbesnoitiosisareassociatedwithmultiplicationoftachyzoitesnexperimentalnfectionsandchronicesionswithhecyststagennaturalnfec-tions.Acuteesionsarecharacterizedbynecrosisofn- fectedissue.Chronicesionsesultfromdisplacementofnormalissuebycysts(CP29 .1 ,29.3)and granulomatousnflammationassociatedwithuptureofcysts.Mostoftentheresnonflammatoryreaction.Aprotozoanparasite,morphologicallysimilartothecyststageofBesnoitia,nfectsknots(Caiidriscanutus),migratorybirdsnthefamilyScolopacidae,withsometimesfataleffects.Cystsarefoundnarteriesofseveralorgans.Endaortitis,aswellasend-arteritisofmesentericandmusculararteries,stheprincipalesionCP30) .

ExcretionFertilizationGametogony

MerogonyDefinitivehost(predator)

Digestion

UnsporulatedoocystExogenous

^ jWoftissue cyst .-.-SporulatedoocystIngestion

ingestionG ltract

Besnoitia48


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plate28.Besnoitiaspp.ofanimals:Smallntestineofcatwitfischlzontofwallacei,X6 30(84-9444).28.2,Smalln-ofcatwithgamontofS.wallaceiIn cell,X 5 00(84-9445).28.3,Hindiegofrat(Dipodomysordii)withwhite,aised,subcutaneouscystsajellisoni (84-9446).28.4,Skullsof

kangarooatsshowinguninfectedskull(right)andnfectedskull(left)withperfora-tionsInmastoldbonesduetocystsofB.jellisoni(84-9447).28.5 ,SkinofmousewithcystsofB.jellisoninsubcutaneoustissue,X 25(84-9448).28.6,HighermagnificationofcystofB.jellisoniwithhostcellnucleincystwail,X400,PASHstain(84-9449).

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29.5 29.6 Colorplate29.Besnoitiaspp.ofanimals:29.1,SkinofoxwithnumerouscystsofB.besnoitindermis,X25(84-9450).29.2,Highermagnificationofcystof.besnoitiwithhypertrophyandncreasednumberofhostcellnucleinwallofcyst,X25 0 (84-9451) .29.3,EyelidofcaribouwithnumerouscystsofB.arandindermis,X 5

(84-5288).29.4,JugularveinofbluewildebeestwithnumerousBesnoitiap .cystsprotrudingntoumen(84-9452).29.5,SpleenofspottedizardwithnumerouscystsofBesnoitiap .,X6 0(84-9453).29.6,Myocar-diumofspottedizardwithhostcellnucleincystwall(lowerleft)andnumerousbradyzoites(upperright),X6 30(84-9454).

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3 0 . 6 plate30.esno/f /a-llkeorganismof30.1,Mesentericarterywithorganismshypertrophledendothel ia lcellsprotruding umen,X60(84-9455).30.2,Higtierofsameartery,X160(84-9456).Highmagnif icationshowingnumerouscellnucleisurroundingvacuolecontain-uninucleateorganism,X630(84-9457).

30.4,Highmagnif icationshowingelongatebasophl l icnucleusofparasitewithinvacuoleInhostcells,X630(84-9458).30.5,Kidney tubuleswithmultlnucleatedmerontsncuboidalcellsprotrudingntoumen,X630 (84-9459).30.6,Kidneytubulewithnumerousmeronts,X630 (84-9460).

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ToxoplasmaandHammondiaTh ecoccldiumToxoplasmagondiiinfectsallwarm-bloodedanimals,ncludinghumans.Fellds(bothdomesticandwild)aretheonlydefinitivehosts;felidsandnonfelldsareintermediatehosts.Toxoplasmacanbetransmittedtointermediatehostsviaoocystsn felinefeces,viacystsnhosttissues(meat),andviatachyzoitestransplacentally.Unsporulatedoocysts(-10 mndiameter)nfelinefeces(CP31 .2 )sporulateoutsidethebodyandbecomeinfectious.Onngestion,sporozoltesexcystandmultiplyntheintestineandassociatedymphnodesastachyzoites.Tachyzoites(rapidlymultiplying,crescent-shapedzoltes,4to6 / mlong)multiplybyendodyogeny(twoprogenyformingwithinaparentcell)fornumerousgenerations,spreadingthroughtissuesandcirculation,andhenencyst.Cystspersistmostfrequentlynthebrain,liver,muscles,andetina.Theyareusuallysphericalorelongate(1 0to1 00 / tmong),thin-walledstructurescontainingafewtoseveralhundredslenderPAS-positlvebradyzoitesorslowlymultiplyingzoites(CP32.3-32.5) .Cystsingestedbyanonfelinehostreleasebradyzoites,whichbecometachyzoites,and thecycleIsrepeated.nfectionbyeitheroocystsorcystsduringpregnancycanresultntransplacentaln- fectionofthefetuswithtachyzoites.Toxoplasmastransmittedtocatsthatngesteithersporulatedoocystsortissuesnfectedwithtachyzoites,butthemostcommonsourceofnfectionsingestionoftissuescontainingcysts.Onngestionofcysts,bradyzoiteseleasednthegastrointestinaltractini-tiateanenteroepithellalcycleofasexualandsexualmultiplication(CP31 . 1 ) ,followedbyoocystdevelopmentandsheddingofunsporulatedoocystswithfeces.Anex- traintestinalcycle,ikethatseennnonfellds,aisooc-cursncats.Tachyzoitemultiplicationesultsnfocalnecrosis(CP32 . 1 ,32.2),themostcharacteristicesionoftox-oplasmosis.nflammationusuallyfollowsnecrosis.Pneumonltisisthepredominantesionnfatalox-oplasmoslsncatsanddogs(CP31.4);placentalnecrosiswithwhiteflecksormultiplewhite,chalky,necroticnodules(CP32 . 1 )andassociatedabortion re -dominateInsheep(CP33 )andgoats.HIstologically,thisnecrosissconfinedtothecotyledonswheren-dividualandsmallgroupsoftachyzoitesareoftendif-ficulttorecognizeamongdegeneratinghostceils.Encephalomyelltissthepredominantesionnsheepandgoatfetuses.DiagnosisofToxoplasmaisalsoaidedbysrologietestsandbybioassayorxenodiagnosisnmice.

Intermediate host(nonfelinevertebrates)

Toxoplasma

Hammondiahammondisanonpathogeniccoccidianofcatscloselyrelatedto .gondii.tsifecycleandstructureareessentiallythesameasthoseof .gondiiwiththefollowingexceptions:(1 )H.hammondihasno extraintestinalcyclenthecat;(2)intermediatehostsbecomeinfectedonlybyingestionofoocysts;and(3) definitivehostsbecomeinfectedonlybyIngestionofcystsntissuesofntermediatehosts(CP32 .6 ) .Dif-ferentiationofH.hammondifromTgondiimustbe basedonalife-cyclestudy.

Excretion

Gametogony 'Merogony

Definit ivehost(predator)Digestionof cyst

UnsporulatedoocystExogenous SporulatedoocystIngestion^Gltract

IngestionGltract

Hammondia

5 2


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31.5 31 . 6 Colorplate31.Toxoplasmagondiiofanimals:31 . 1 ,Smallntestineofcatshowingnumerousasexualandsexualstagesnepithelialcellswithmacrogametesntwocells(left),microgamontncell(center),andmerontncell(right),X 00 0(84-9533) .31.2,FecesofcatwithtwounsporuiatedoocystsInecalfloat,X1000(84-9534) .31.3 ,Lungofcatwithnurrjeroustachyzoltesn

macrophagesnalveolarlumen,X1000(84-9535) .31.4 ,Lungofcatcontainingnumerousoval-to-roundtachyzoltes,eachwithbasophllicnucleus,X1000(84-9536) .31 . 5 ,LungofcatwithunatetachyzoitesnImpressionsmear, 000,Glemsastain(84-9537) .31 . 6 ,KidneyofgoatwithnumeroustachyzoitesIntubularepithelium,X1000(84-9538).

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CJUMH

32.1

^^^K'*"

< #BM^m ^B

32.5 32.6 Colorplate32.ToxoplasmaandMammon-diaofanimals:32.1,Placentaofsheepshow-ingcotyledonwithnumerous yellowish-whitenecroticfocinvilli(84-9539).32.2,Placentaofsheepwitnmult ifocalnecrosisnvilli,X3 ,PASstain(84-9540).32.3,Brainofmousewith cyst(uppereft)andgroupoftachyzoites(lowerright),whichareargerthan bradyzoites,X1500(84-9542).32.4,BrainofmousecontainingfourcystswithPAS-

poslt lvebradyzoites,X630,PASHstain (84-9543).32.5,Brainofmousecontaining cystwiththinargentophil icwallandnumerousbradyzoiteswithterminalor subterminalnucleusnmpress ionsmear,X1000,Gomorimethanamlnesi lver-Glemsastain(84-9544).32.6,Skeletalmuscleof mousewithH .hammondicyst,X630,PASHstain(84-9580).

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plateZZ. Toxoplasmaabortionof Darkerlamban dassociatedetalareseverelyautolyzed. Ligfiterandassociatedetalmembranesar e autolyzed. Lesions,cfiaracteristicof refoundncotyledonsofbotfi

(Scale=2.5 cm )

5 5


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CoccfdiaofUnde te rm inedTaxonom i cStatus Coccidia-likerganismsaveee nbservedithightan dlectron icroscopynissuesforses,attle,an dheep .herganismsp pea r orphologically similaro erontsf Sarcocystis,utecausetherstagesfheifeycleaveotee nbserved,heirtaxonomictatusemainsndetermined.heourcesofuc hnfectionsreotnown.Inorses,rganismsnheloodesselsndeuralcellsfheentralervousystemaveee n associated ithncephalomyelitisCP34 . 1 ,4.2).nsheepCP34 .3 -34 .6 )ndalvesCP35 . 1 - 35 .4 ) , imilarorganismaseenssociated ithimilaresions.Inbortedetalorses,rganismsnndeterminedcellsnheun g (CP35 .5 -35 . 6 )p pea r imilaro merontsfarcocystis.Inogs,erma lodulesontainoccidiantages within acrophagesCP36 . 4 ,6 .5 ) .heyreocatednth eermisndppear imilaroaryospora.Inirds,in y erozoiteliketagesaveeenoundnth entestine.omep pea roentracellularnd othersxtracellularCP36 . 6 ) .Coccidiafheenusalyposporaaveeenepor ted onlynishCP36 . 1 ) ,hereheocystsporulatensitunheiver.ocystsesembl inghosefalyp-osporaav eee noundnheiversfrocodiles(CP36 .2) .snomethergenerafoccidia,hesporozoitesrecid-fastCP36 . 3 ) .


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plate34.Coccldiaofundeterminedstatuscausingencephalomyelltis

domesticanimals:34 . 1 ,Medullaoblongatafiorsewithargedarkfocalesionbynecrosis(84-9545).34.2,cordofhorsecontainingorganismsneuron,X1000(84-9546).34.3,Spinalofsheepshowingocalnecrosiswith

perivascularinfiltration,X5(84-9547).34.4,Cerebrumof3-weel


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35 . 5 35.6Colorplate35.Coccidiaofundeterminedtaxonomicstatusofanimals:35 . 1 ,Spinalcordofbovinecalfwith everesubmeningealperlvascularinfiltrationnwhitematter,X25 (84-9551) .35.2,Highermagnificationof35.1 withgroupofzoitesnparenchyma,X 000(84-9552).35.3 ,Spinalcordofbovinecalfcon-tainingcystlil


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36 .4

# ^* 41 m mplate36.Calyptosporaandorganisms

undeterminedtaxonomicstatusofnimals:36 . 1 ,LiverImpressionsmearoffish;

notesporulatedoocystsofC .unduli,X250036.2,Liverofcrocodilewithoocystsofcoccidianperhaps

elatedtoCalyptosporaspp.,X1000 36 . 3 ,Liverofcrocodilew/lthcoc-n36 .2containingacid-fastsporozoitesmature,X 000,acid-faststain36.4 ,Skinofdog;notegamontsand

36 .6 gametesofcoccidiannhostcellsperhapsrelatedtoCaryosporaspp.(CP20) ,X25 0(84-9575) .36 . 5 ,Skinofdogwithhostcellnucleus(dark,owerright),threemacrogametes,andonemicrogamont(upperrightwithperipheraldarknuclei)thatmaybe relatedtoCaryosporasp .(seeCP20) ,X 5 00 (84-9576) .36 . 6 ,Smallntestineoffinchwithtinyorganismsintracellularlyandex -tracellularlythatmaybeIsosporaspp.,X 1500(84-9577) .

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KQSsef aKIossIeHaspp.havebeendentifiedmostcommonlynequidSjmice,andguineapigsandtoalessextentn bats,opossums,variousodents,an daboaconstrictor.Stagesoftheorganismarefoundnthekidney(CP37) .Thelifecyclesnotclearlyunderstood.nepithelialcellsoftubules,trophozoitesformschizontsandmerozoites,andromtheseschizonts,gametesare thoughttoform.Fertilizedgametesarebelievedtodevelopntosporonts,whichbudtoformsporoblasts(CP37 .2 ,37.5) .Eachofthesesporoblastsundergoessuccessivedivisionstoformsporocyststhatcontain

sporozoites(CP37 .3 ,37.6) .Maturesporocystsaresur-roundedbyathickwallandpassfromthebodynheurine.Theyarethoughttobelateringestedbyanotherhost,andsporozoites,eleasedromthesporocyst,movetothekidney,wheretheyenterepithelialcellsandnitiatethecycle.Onlyheavilyparasitizedkidneyshavegrossesions,whichappearastinygrayfocionthecorticalsurface.Microscopicallythesefociareareasofnecrosis,withperlvascularinfiltrationofinflammatorycells,especial-lylymphocytesandhistiocytes,andwithanncreasen interstitialfibroblasts.

Schizont

Ingestion

Kidney tubule epithelium

-MicrogametesMacrogametes

TrophozoiteMaturesporoblasts

Free'^ sporoblasts

Klossiella

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plate37.Klossiellaspp .ofanimals:KidneyofhorsecontainingK .equiwithbuddingsporont(top),sporontwith sporoblasts(bottomeft),andsporocysts(right)withintubular X 25 0(84-5266).37.2,Epithelialofhorsekidneytubulecontaining ofK .equi,withsporoblastsbuddingcentralresidualmass,X630 (84-9461).Kidneyofhorsewithfreesporoblastsof

K .equicontainingnumerousnuclei,X 630 (84-5264).37.4,Kidneyofguineap igInfected withK .cobayae,X25 0(84-5257).37.5,Epithelialcellsofkidney tubuleofguineap igcontainingbuddingsporontsofK .cobayae,withsporoblastsbuddingfromcentralresidualmass,X630 (84-5256).37.6,Kidneyofguineap igwithmultinucleatedsporocystsof K.cobayae,X 630 (84-5260).

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HaemogregarlnaHaemogregarinaspp.areparasitesofreptiles,amphib-ians,birds,andsonnennammals .Theyaretransmittedtothesehostsbynvertebrates,suchaseeches,ticks,mites,mosquitoes,andotherhematophagousn- vertebrates.nvertebratesbecomenfectedbyngestingbloodromannfectedvertebratehost.Whenbloodcellscontaininggamonts(CP38 .3 )areysednthegutoftheinvertebratehost,gametesfuseandanoocystdevelops.Thissporulatestoformsporozoites,whicharenjectedntothecirculationofthevertebratehostduringeedingorarengestedfthenvertebratehostiseatenbythevertebrate.Haemogregarinesporozoitesnfecterythrocytesofthevertebratehost,wheretheyformtrophozoites,and thesegrowintoschizonts,whichfillthecells.The enlargederythrocytescontainingthemacroschizontsoftenappeartobeextracellularnissuesections(CP38 .1 ,38.2).Developingschizontshavenucleiattheperiphery(CP38 .1 ) ,andwhenmaturethemerozoitesare crescentshaped(CP38.2) .Merozoiteseleasedromthemacroschizontsenterothererythrocytesandormasecondgeneration,which,beingsmallerthanthefirstgeneration,aretermedmicroschizonts.Merozoitesreleasedfromtheseentererythrocytesanddevelopintoeithermicrogamontsormacrogametes.Thisendsdevelopmentnthevertebratehost.Hepatozoon Hepatozoonspp.nfectodents,squirrels,canids,felids,accoons,mink,andothercarnivores,aswellas birdsandeptiles.Schizontsmaybefoundnmanyvisceralorgansandtheskeletalandheartmuscles,buttheyaremostcommonnthespleenandiver.Hepato-zoonspp.aretransmittedtovertebratehostsbyticks,mites,ice,tsetseflies,mosquitoes,andotherblood-suckingarthropods.Th earthropodsbecomeinfectedby ingestingbloodromannfectedvertebratehostwithgametocytesneukocytes.Gametesreleasedfollowingdigestionofeukocytesnhenvertebrategutundergofertilizationtoformanookinete,whichundergoessporogonytoformsporozoites.Whenhenvertebrate

isngested,sporozoitesarereleased.Theyenterthebloodstream,arecarriedotheiver,andtheneavethecirculationandenterhepaticparenchymalcells,wheretheyformschizonts.Th eschizonts,asntheHaemogregarinaspp.,atfirsthavenucleiattheperiphery(CP38.4) .Latercrescent-shapedmerozoitesbudfromaresiduum(CP38.5) .Schizontsappeartobe freentissuesectionsbutactuallyarentracellularnvariousvisceralcells.Merozoitesproducednschizontsreentercellsntheiver,producingateastthreegenerationsofschizonts.Th efinalgenerationproducesmerozoitesthatentermononuclearleukocytesand becomemicrogamontsandmacrogametes(CP38 .6 ) .Awidespectrumofesionshasbeeneported,varyingfromverymildcellularinfiltrationonecrosiswithac- companyingcellularinfiltration.Dependingonheaf- fectedorgan,extensivereticuloendothelialcellhyperplasiahasalsobeeneported.

Hepatozoon

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38.6 plate38.Haemogregarinasp .and

canisofanimals:38.1 ,Liverofconstrictorcontainingdevelopingscfil-ofHaemogregarinasp . ,X1 5 00(84-9462). Lungofboaconstrictorcontainingschi-ofHaemogregarinasp . ,X1 50 0(84-9463). Erythrocyteofboaconstrictorcontain-macrogameteormicrogamontofsp . ,X1 5 00(84-9464).38.4,

SpleenofdogcontainingdevelopingschlzontofH.canis,X1000(84-9465) .38.5 ,SpleenofdogcontainingschlzontofH.canis;noticezoltesbuddingfromesidualmass,X1500 (84-9466) .38.6 ,PolymorphonuclearleucocyteofdogcontainingmacrogameteormicrogametocyteofH.canis,X1500 ,Glemsastain(84-5285) .

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PlasmodiumPlasmodiumspp.nfectmostgroupsofhighervertebrates.Mostaretransmittedtovertebratehostsby femalemosquitoes.Theseandotherarthropodhostsbecomenfectedbyingestingmacrogametesand microgamontsnthebloodofannfectedvertebrate.ntheinvertebratemidgut,theatterformmicrogametes,whichunitewithhemacrogametestoproducezygotes.Th ezygotetransformsntoamotileookinete,whichpenetratesthegutwallandentersthecoelom,whereitdevelopsntoanoocyst.Oocystsundergosporogony,producinghousandsofsporozoites,whichareinjectedintothevertebratecirculationwhenthenvertebratetakesabloodmeal.Sporozoitesnvadeivercellsnmostvertebrates,wheretheyproduceexoerythrocyticschizonts.Thisormmultipliesasexuallytoproducetensofthousandsoftissue-stagemerozoites.Merozoitesnvadeerythrocytes,wheretheytransformintotrophozoites(thefeedingorringstage)andmulti-plyasexuaflytoproduceaschizontcontaining8to32erythrocyticmerozoites.Thesemerozoitesnvadeothererythrocytes.Th esexualphasebeginswhensomemerozoitesnerythrocytestransformintomacrogametesandmicrogamonts.Grossesionsnseveremalariamayncludepallorcausedbyanemia,brown-tingedskinandmucousmembranesduetomalarialpigment,splenomegaly,anddarkeningoftheviscera,especiallyliver,spleen,lungs,andbrain,duetoconcentrationofthepigment.Microscopiclesionsaremostobviousntheblood,whereerythrocytestructuremaybealtered.Duringthebloodphaseofinfection,theremaybehypertrophyofKupffercellsnheiver,withaccumulationofmalariapigment,nterlobularinflammation,andglycogendeple-tionfollowedbyfattyinfiltration.nthekidneys,theremaybepigmentaccumulationnmacrophagesandparasitesnerythrocytesnveins,fattydegenerationoftheparenchyma,andpossiblymmunecomplex

glomerulonephritis.nheungs,theremaybeac- cumulationofpigmentnmacrophagesnthecapillaries,obstructionofthevasculatureandym -phatics,andpulmonaryedema.nhespleen,theremaybehyperplasiaofedandwhitepulp(primarilylymphocytesandmacrophages),congestion,and erythrophagocytosis.Diagnosissprimarilybythickorthinbloodsmears.n- traerythrocyticorganismsstainedwithGiemsaar ere d (chromatin),blue(cytoplasm),andyellovA/toblack(pig-ment)CP39.1-39 .3 ,40.1) .

Sporozoite

W Merozoite/

Preerythrocytic schizogony inliver cellsMature segmenter (meront)withmerozoitesYoungk schizonf .;i *n .^-^ ^erozoiteTrophozoiteor -enters RBC ringstage

Plasmodium

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0^' I$

^ 39.2

plate39.Plasmodiumspp .ofbirds:Bloodsmearfromstarling;noteschl-(right,center)ofP .relictumwith nuclei,X1500,Glemsastain 39.2,Bloodsmearfromstarling macrogameteofP .relictum,X1500,stain(84-9468).39.3,BloodsmearstarlingwithgamontofP .relictum,X

39.6 1500,Glemsastain(84-9472).39.4,LungofpenguinwithexoerythrocyticschlzontofPlasmodiumsp.,X1500(84-9469).39.5,En-dothellalcellofturkeybrainwithex-oerythrocyt icschlzontofP .durae,X1500(84-9470).39.6,Endotheliumofturl


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HepatocystisHepatocystisspp.parasitizearborealtropicalmammalsoftheOldWorld,especiallysquirrels,ruitbats,and lowermonkeys,aswellasdeermiceandheh ip-popotamus.Sporozoites,noculatedntothecirculationduringeedingbytheyector(Culicoidesspp . ) ,enterthehepaticparenchymalcellsofthemammalsanddevelopintomeronts.Thesemeronts,termedmerocysts,mayreach4-6mmndiameter(CP40.4-40.6) .Asthemerocystsenlarge,ab igvacuoleformsnthecenterandillswithcolloid(CP40.4) .Merozoitesdevelopattheperipheryofthemerocyst.Whenmerocystsmaturein or2months,heyruptureandeleasemerozoites,whichnvadeerythrocytesandresembletheringstageofPlasmodiump p .(CP40.2) .Multinucleatebodiesare alsoeleasedromthemerocystsoccasionally.They

enterthecirculationandarecalled"corpsplasma-tiques."Theirfunctionsnotknown.Microgamontsandmacrogametesdevelopnerythrocytes.Afteringestionofbloodcontaininggametocytesby thenvertebratehost,microgametesareformed,andfertilizationand sporogonytakeplace.LesionsobservedmicroscopicallyareusuallylimitedoInflammatorycellsaroundmerocysts.DifferentiationofHepatocystisspp.romotherhemoproteidparasitessbasedonstructureandstain-in gcharacteristics.Forexample,whenstainedwithGiemsa,microgamontsofHepatocystishaveanunusualnucleus,withaarge,oval,pinknucleoplasmthatoccupiesone-thirdormoreoftheparasite.Withinthenucleusar enumerousedchromatingranulesorthreads.

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40.6 Colorplate40.Plasmodiumsp .andHepatocystissp .ofnonhumanprimates:40.1,Bloodsmearfrommonkeyshowing rophozoite(left)andscfilzont(right)ofP .cynomolgi,X1500,Giemsastain(84-9473).0.2,BloodsmearfrommonkeywithtrophozoiteofHepatocystissp.,X1500,Giemsastain(84-9474). 40.3,Bloodsmearfrommonkeywithmacrogameteof

Hepatocystissp.,X1500,Giemsastain(84-9475). 40.4,LiverofmonkeywithmerocystofHepatocystissp.,X60(84-9476). 40.5,Highermagnif icationof merocystshowingformationofmerozoites,X 160(84-9477). 40.6,Stillhighermagnif icationofmerozoiteformationnwallofmerocyst,X 25 0(84-9478).

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TheilenafSyn.,Cytauxzoon)TheileriahasbeeneportedamongdomesticandwildungulatesnsouthernAfricaandnwildanddomesticfelidsnseveralStatesntheUnitedStates.Domesticcatsarethoughttobeaccidentalhosts.Ticksarethevectors.ntraerythrocyticstages(trophozoites)maybe absentorpresentnthecirculatingblood.Theyvarynstructurefromroundtoovalwithaneccentricnucleus,ortheymaybeelongatewithbipolarchromatinbodies.Schizonts(meronts)arefoundneukocytes,erythroblasts,histiocyticmacrophages,andotherhostcells.DevelopingschizontshavenumerousargevesicularnucleiC P41.2-41.4) ,whereasmatureschizontscontainmyriadsofuninucleatemerozoiteswithsmallnucleiCP41 .4 ,41.5) .Merozoiteseleasedfromschizontsnvadeerythrocytes(CP41 .6 ) . Th emostcharacteristicesionstheocclusionofthelumenofmediumandsmallbloodvesselsand sinusoidsnorgans,ncludingheheart,iver,ung,lymphnodes,kidney,andspleen,withargeschizont-containingmacrophages(CP41 . 1 ) .

Theileria

Theileriaspp.arediagnosednmammalianissuesasschizontsneukocytes,macrophages,andothercellsandastrophozoitesnerythrocytes(CP41 .6 ) .

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0 0 i1 .1 41 .2

plateA\.Theleriafelis (syn.,Cytaux-felis)ofcats:41.1,SplenicarterywithofT .felis occludingumen,X100 41.2,Macrophagecontainingschl-ofT .felisthatseemstobudfromen-ofpulmonaryvein,X630 (84-5278).Pulmonary vesselwith threedevelopingofT .fells,X 630(84-5284). 41.4,

41.6 Pulmonaryvesselwithdevelopingan dmature(left)schlzontsofT .fells,X630 (84-5283). 41.5,Capi l laryofglomerulus with schizontofT .felis,X630 (84-5282).41.6,BloodsmearwithtrophozoitesofT .fells n erythrocytes,X1500(84-9486).

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H 'c42.2

plate42.PIroplasmsandrickettslaefanimals:42.1,PeripheralbloodsmearofigwithIntraerythrocyticBabesiatrautman-X1500,Neltzstain(84-9479).42.2,bloodsmearofdogwithIn-B.canis,X1500,Glemsastain 42.3,PeripheralbloodsmearofwithIntraerythrocyticS .caballi,X Glemsastain(84-9481). 42.4,

42.6 PeripheralbloodsmearofhorsewithIn-traerythrocytic Anaplasmamarginale,X1500,Giemsastain(84-9482). 42.5,Peripheralbloodsmearofdogwithntraleucocytic EhrllchiacanIs,X1500,Neltzstain(84-9483). 42.6,LymphocyteswithinymphnodeofcowcontainingIptracellularThelleriapan/a,X1500(84-9484).

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Haemoproteus Haemoproteusspp.arefoundprimarilynbirds;someparasitizeturtlesandizards.Ofover80namedspecies,manyarendistinguishablefromoneanother,arenamedonhebasisofthehostnwhichheyare found,andhavencompletelyknownifehistories.Allspecieshavensectvectors,suchasmidges,h ip-poboscids,ortabanids.Sporozoitesnthesalivaryglandsofthensectvectorarethoughttoenterthecir-culationofthevertebratehostwhenthensectbites.Th efirststageseennvertebratesstheelongate,twistedschizontnhevascularendotheliumofthelung(CP43 . 1 ,43.2),iver,kidney,andspleen.Merozoitesdevelopwithintheschizontnclusters.Whenmature,theyarereleasedntothecirculationastiny(1-2pm )roundbodies.Theyentererythrocytes(CP43.3) ,wheretheytransformintomacrogametesormicrogamonts,theonlystagesseennhensectafteringestionofn- fectedblood.Parasitemiaexceeding5 0percentoferythrocyteshasbeenobservedwithoutsignsofdisease.Diagnosissprimarilybasedondentificationofmicrogamontsormacrogametesnbloodsmearsorofschizontsnsmearsorsectionsoforgans.Leucocytozoon Leucocytozoonspp.arefoundnbirds.Ofover70 namedspecies,manyarendistinguishablefromoneanother;theyarenamedbecauseofbeingoundndif-ferenthostspecies.Theirlifehistoriesarencompletelyknown.Allspecieshavensectvectors,suchasmidgesandsimulildlies.Sporozoitesnthesalivaryglandofthensectenterthecirculationofthebirdwhenhen- sectbites.Firstgenerationschizontsofmostspeciesthendevelopnhepaticparenchymalcellsandwhenmaturereleasethousandsoftiny 1ivn)roundmerozoitesthatarethoughttoinitiateasecondgenera-tionnhepaticparenchymalandphagocyticcellsthroughoutthebody.Thosenphagocyticcellsusuallybecomeveryarge(100-200im)megaloschizonts(CP43.4) .Whenmature,theyreleasemillionsoftiny(1x W i )roundmerozoitesthateitherinitiateschizogonyinhepaticparenchymalcellsorentercirculatingerythrocytesorleukocytes,wheretheydevelopntomicrogamontsormacrogametes.Thoseofsomespeciesareexclusivelyround(CP43.5 ) ,andhoseofotherspeciesarethoughttoberoundatonetimeandelongate(CP43 .6 )atanother.Sexualmaturation,er- tilization,andsporogonytakeplacenhensectafteringestionofinfectedblood.

ForthosespeciesofLeucocytozoonthatare pathogenic,hebasicesionsdestructionoferythrocytesesultingnanemia.nflammatoryand necroticfocimaybefoundntheiver.Diagnosissprimarilybasedondentificationofgamontsorgametesnbloodsmearsorofmegaloschizontsnsmearsorsectionsoforgans.

Haemoproteus

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plate43.Haemosporozoaofbirds:Lungofpigeonwithnumerous

ofHaemoproteussp.,X1500 43.2,LungofpigeonwithsinuousofHaemoproteussp.,X1500 43.3,Bloodsmearfrompigeonmerozoltes(smallorganisms)andargerormacrogametes ofsp .withinerythrocytes,XGlemsastain(84-9488). 43.4,Brainof

43.6 duckwithmegaloschlzontofLeucocytozoon simondi n cellwithdistincthypert rophiednucleus,X6 30 (84-5300). 43.5,LungofrobinwithroundmicrogamontsormacrogametesofLeucocytozoonsp .n erythrocytes,X630 (84-9489). 43.6,LiverofduckwithelongatemicrogamontsormacrogametesofLeucocytozoonsp . n erythrocytes,X1000(84-9490).

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HaemosporozoaofUndete rm inedTaxonom cStatus Large"cysts"ofhaemosporozoahavebeeneportedfromthegizzard,skeletalandcardiacmuscles,and visceralorgansofavarietyofbirds(CP44 . 1 ,44.2).nthesereports,gamontsandgameteshavenotbeen foundnperipheralbloodsmears.nsomecyststhecontentsarecompartmentalizedbyinternalsepta(CP44.3-44.5) .Hemorrhagessometimesassociatedwithcysts,andbloodcellsappearwithinoramonggroupsoforganisms(CP44 . 5 ,44.6).

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44.6 plate44.Haemosporozoaofbirds:Pancreasofchickenwithschizontsofcaulleryi(syn.,Akiba

X 6 0(84-9491). 44.2,GizzardofwithschizontsofLeucocytozoon-organism,X6 0(84-9492). 44.3,Skeletal

ofcurawongwithschizontoforganism,X6 0

44.4,Muscleofquailwithcom-

partmentalizedcystofhaemosporozoan,X 40 0(84-9494).4.5 ,Muscleofquailshowingcompartmentalizedcystofhaemosporozoanwitherythrocytesscatteredamongcompart-ments,X25 0(84-9495).4.6 ,Liverofpigeoncontainingcystofhaemosporozoanwithorganismsatperipheryandargeemptycen-tralarea,X1 6 0(84-9496).

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Fung

Somegeneraoffungiar eoffenmistakenforprotozoans.Diphasicfungidevelopasyeastsnanimalissuesand areoftendifficulttodentify.YeastformsofHisoplasmacapsulatumandCandidaalbicans( CP45 )aresimilartoamastigotesofLeishmaniaspp.( CP1 . 2 )andTrypanosomacruz/(CP 1 . 5 , .6).Somefungiormsporesorsporangiathatesembleprotozoancysts.Forexample,sporesofEmmonsiaspp,