Protozoa Protozoa

General characteristicsGeneral characteristics

UnicellularUnicellular Variation in size shape, locomotor Variation in size shape, locomotor

apparatusapparatus Majority are free livingMajority are free living Some are parasiticSome are parasitic

Morphology Morphology

Ectoplasm Ectoplasm

Locomotor apparatusLocomotor apparatus– PseudopodsPseudopods– FlagellaFlagella– CiliaCilia– Undulating membraneUndulating membrane

Procurement of foodProcurement of food– periostomeperiostome

Discharge of metabolic wasteDischarge of metabolic waste– cytophagecytophage

ENDOPLASMENDOPLASM

Contractile vacuoleContractile vacuole– Regulating osmotic pressureRegulating osmotic pressure

OrganellesOrganelles NucleusNucleus

– karyosomekaryosome

Stages of developmentStages of development

Trophozoite Trophozoite – VegetativeVegetative– MotileMotile– Infective stageInfective stage– Obtained from semi formed stoolObtained from semi formed stool

CystCyst– Non motile stageNon motile stage– Resistant stageResistant stage– Sexual reproductionSexual reproduction

Mitotic or amitoticMitotic or amitotic

– Sexual union of two cellsSexual union of two cells Temporary union or conjugationTemporary union or conjugation

Amoeba Amoeba

General ruleGeneral rule

Inhabits the large intestine ex. Inhabits the large intestine ex. Entamoeba gingivalisEntamoeba gingivalis

Most develops into cystic stage ex. Most develops into cystic stage ex. Entamoeba gingivalis ad Entamoeba gingivalis ad dieentamoeba fragilisdieentamoeba fragilis

Commensals except entamoeba Commensals except entamoeba histolyticahistolytica

Amoebiasis- entamoeba histolyticaAmoebiasis- entamoeba histolytica

EntamoebaEntamoeba– HistolyticaHistolytica– ColiColi– HartmaniiHartmanii– gingivalisgingivalis

EndolimaxEndolimax IodamoebaIodamoeba Dientamoeba Dientamoeba

Entamoeba Entamoeba histolyticahistolytica

TrophozoiteTrophozoite

Elongated Elongated Changes shape when staionaryChanges shape when staionary Clean looking cytoplasm with RBCClean looking cytoplasm with RBC Small centrally located Small centrally located

karyosomekaryosome

cystcyst

RoundRound With sausage shaped/cigar With sausage shaped/cigar

shaped chromatoidal barshaped chromatoidal bar 1-2 nuclei1-2 nuclei Small karyosomeSmall karyosome

Life cycleLife cycle

Large intestineLarge intestine FecesFeces Ingestion of mature cystIngestion of mature cyst Cyst in the G.I. tractCyst in the G.I. tract Encyst in the S.I. trophozoite reach Encyst in the S.I. trophozoite reach

the colonthe colon Invades intestinal wall encystation in Invades intestinal wall encystation in

the large intestinethe large intestine

Disease associatedDisease associated

Asymptomatic amoebiasisAsymptomatic amoebiasis– CarrierCarrier

Acute symptomatic amoebiasisAcute symptomatic amoebiasis– Amoebic diarrheaAmoebic diarrhea

Soft stool and extensive ulcerSoft stool and extensive ulcer

– Acute amoebic dysenteryAcute amoebic dysentery Stool with blood and mucusStool with blood and mucus tenesmustenesmus

Chronic amoebic dysenteryChronic amoebic dysentery Tumor like mass called amoebomasTumor like mass called amoebomas

Extraintestinal Extraintestinal

HepaticHepatic PulmonaryPulmonary CerebralCerebral Amoebic pericarditisAmoebic pericarditis Cutaneous amoebiasisCutaneous amoebiasis Genital amoebiasisGenital amoebiasis

Diagnosis and Diagnosis and treatmenttreatment DFSDFS

– Quensel’s solutionQuensel’s solution– Lugol’s solutionLugol’s solution

CutureCuture– Locke’s egg serumLocke’s egg serum– NA salineNA saline

SerumSerum– ELISAELISA

Rectal biopsyRectal biopsy Extra intestinalExtra intestinal

– Liver aspirate/scanLiver aspirate/scan– Serological testSerological test

TreatmentTreatment– MetronidazoleMetronidazole– TinidazoleTinidazole– Diloxanide furoateDiloxanide furoate

Cyst Cyst

Trophozoite Trophozoite

Non pathologic Non pathologic amoebaamoeba Entamoeba coliEntamoeba coli

– TrophozoiteTrophozoite Sluggish movementSluggish movement Dirty looking cytoplsmaDirty looking cytoplsma Large eccentric karyosomeLarge eccentric karyosome

– CystCyst 1-8 nuclei1-8 nuclei Broomstick chromatoidal barrBroomstick chromatoidal barr

cystcyst

Endolimax nana- smallestEndolimax nana- smallest– TrophozoiteTrophozoite

Central or eccentric karyosomeCentral or eccentric karyosome Plenty of pseudopodiaPlenty of pseudopodia sluggishsluggish

– CystCyst Oval with 1-4 nucleiOval with 1-4 nuclei Large karyosomeLarge karyosome Cross eyed cystCross eyed cyst

Trophozoite Trophozoite

Cyst Cyst

Iodamoeba butschiiIodamoeba butschii– TrophozoiteTrophozoite

Leaf likeLeaf like Round pseudopodiaRound pseudopodia Slow movingSlow moving Cytoplasm with glycogen vacouleCytoplasm with glycogen vacoule

– CystCyst With single nucleusWith single nucleus With glycogen vacouleWith glycogen vacoule

Trophozoite Trophozoite

Cyst Cyst

Dientamoeba fragilisDientamoeba fragilis– TrophozoiteTrophozoite

Small rounded with nucleiSmall rounded with nuclei Blunt leaf like pseudopodiaBlunt leaf like pseudopodia Sluggish movementSluggish movement

Entamoeba gingivalisEntamoeba gingivalis– TrophozoiteTrophozoite

Oral parasiteOral parasite Fast and vigorous movementFast and vigorous movement Multiple pseudopodiaMultiple pseudopodia

Free-living Free-living pathogenic amoebapathogenic amoeba

Naegreria Naegreria

Naegleria fowleriNaegleria fowleri Amoeboid/flagellatedAmoeboid/flagellated Portal of entry is the nasal passage Portal of entry is the nasal passage

going to the meninges and braingoing to the meninges and brain Agent of PAM- primary amoebic Agent of PAM- primary amoebic

meningoencephalitis meningoencephalitis FeverFever HeadacheHeadache

Vomiting Vomiting DeathDeath Amphotericin B for PAMAmphotericin B for PAM

Acanthamoeba Acanthamoeba

Active trophozoite stageActive trophozoite stage– Broad pseudopodiaBroad pseudopodia– sluggishsluggish

Dormant cystic stageDormant cystic stage– UninucleatedUninucleated– Double wallDouble wall

Not well defined life cycleNot well defined life cycle

Infects the CNSInfects the CNS GAE- granulomatous amoebic GAE- granulomatous amoebic

encephalitisencephalitis– SeizureSeizure– Stiff neckStiff neck– NauseaNausea– vomittingvomitting

Acanthamoeba keratitisAcanthamoeba keratitis– Corneal ulcerationCorneal ulceration– blindnessblindness

5- flourocytosine5- flourocytosine KetoconazoleKetoconazole ItraconazoleItraconazole Amphotericin BAmphotericin B