ENTAMOEBA HISTOLYTICA BY SADIA FATIMA - pdf

ENTAMOEBA HISTOLYTICA BY SADIA FATIMA 2ND YR MBBS - pdf

1. ENTAMOEBA
HISTOLYTICA
By:SadiaFatima

2. CONTENT
oIntroduction
oDifferentspecies
oMorphology
oLifecycle
oLaboratoryDiagnosis
oTreatmentAndControl

3. INTRODUCTION
•Enteramoebahistolyticaisthemostimportant
pathogenicintestinalamoeba.
•Itcausesamoebicdysenteryandalsoextraintestinal
amoebiasisaffectingtheliver.
•Morecommonintropicalandsubtropicalcountries.

4. DIFFERENTSPECIES
•EntamoebaDispar
•EntamoebaMoshkovskii
•EntamoebaBangladeshi
•EntamoebaColi
Thesespeciesareharmlesscommensalsinhuman
intestine.

5. MORPHOLOGY
•E.histolyticaexistsinthreemorphologicalforms
Trophozoite
Thisisthemotileformof E.histolytica.Itis
invasiveformaswellasthefeedingandreplicationform
oftheparasiteinfeceswithactivedisease.
Precysts
Itisintermediatestage.
Thesearesmallerthantrophozoitesandare
uninucleate.

6. Cyst
Itisthediagnosticformoftheparasitefoundinthe
fecesofcarriersandalsoinpatientswithactivedisease.
Existinimmatureform :uninucleatedandbinucleated.
matureform :quadrinucleated.(infectedform)

7. LIFECYCLE

8. •HOST:E.histolyticacompletesitslifecycleinasingle
hostwhichisman.
•INFECTIVEFORM :Maturequadrinucleatedcystwhich
isalsoknownasmetacyst.
•MODEOFTRANSMISSION :Transmittedmainlyby
feco-oralroute.

9. Pathogenesis

10. LABORATORYDIAGNOSIS
•Samples:
Stoolcollectedformicroscopy
Aspiratefromliverabscesses.
Biopsyspecimenobtainedaftersigmoidoscopy.
•MicroscopyforcystorTrophozoites :
Instoolsquadrinucleatecystsandtrophozoites
areseen.

11. •Serology:
Amoebicantigen:ELISAdetects 170-kDalectin
antigen.
Itisfoundonlyinpatientswithactiveinfection.
Amoebicantibody:ELISAdetects serumantibody
IgGagainstlectinantigen.
Onlyappearsinlaterstages.

12. •Isoenzymeanalysis :
Zymodemepatternscanbeproduced.
ItcandifferentiateE.histolyticafromE.dispar.
Moleculardiagnosis :
NestedmultiplexPCR
TargetssmallunittRNAgenes.Itcandifferentiate
E.histolyticaandE.disparwithgoodsensitivity.(90%)

13. •Real-timePCR-
Targets18SrRNAgene
Moresensitiveandcanquantitatetheparasiteload.
•OtherNonspecificFindings :
1.Imagingmethod-colonoscopydonetodetect
flask-shapedamoebiculcers.
2.Moderateleukocytosisinblood.

14. TreatmentandControl
•Thedrugofchoicetotreatamoebiasisis
metronidazole.
•Otheralternativesincludeiodoquinolanddiloxanide.
•Fluidandelectrolytereplacementandsymptomatic
treatment.
•Avoidingestionofcontaminatedfoodandwaterwith
humanfeces.

15. •References:
EssentialsofMedicalMicrobiology(4thEdition)-
byApurbaSsastry.
AnanthanarayanandPaniker'sTextbookof.
Microbiology(13thEdition)-
EditedbySonalSaxena

16. THANKYOU