Eukaryotic Parasites (Protozoa)

Drs. Babcock and HopkinsSpring 2009

Entamoeba histolytica

(amebiasis, severe diarrhea)

Acquired throughconsumption of contaminated food or water.

Trophozoite is feeding andreproducing stage and causesdisease. Cyst is circular and is what is ingested. Trophozoiteforms pseudopodia.

Target nuclei in both.

Entamoeba Histolytica trophozoites

Entamoeba histolytica cysts

Entamoeba histolytica with ingested erythrocytes

Balantidium coli (balantidiasis)

Trophozoite has cilia. Cystdoes not. Large nucleus.

Can cause diarrhea and in severecases ulcers and abscesses that can lead to dysentery and death.

Balantidium coli

Balantidium coli trophozoites

Balantidium coli trophozoites

Giardia intestinalis - giardiasis

2 nucleiFlagella onTrophozoite.

Giardia intestinalis - trophozoite

Giardia intestinalis trophozoite

Giardia intestinalis trophozoite

Trichomonas vaginalis life cycle

Single nucleusFlagella. NOCYST form.

Vaginitis withmalodorous dischargeand pruritis.

Trichomonas vaginalis trophozoite

Trichomonas vaginalis trophozoite

Tsetse fly

Trypanosoma brucei

Flagellated.Seen in bloodSmear outside of RBCs.

Arthropod vector,Tsetse fly. Infectionthrough bite andcauses African Sleeping Sickness.

Trypanosoma brucei

Arthropod vector- Anopheles is vector

Plasmodium falciparum

Seen in blood smear inside RBCs.Undergoes schizogony. Causes Malaria

Plasmodium falciparumPlasmodium vivaxPlasmodium ovalePlasmodium malariae

Plasmodium falciparum“blackwater fever”

Toxoplasma gondii

Produce toxoplasmosisiIn humans when cysts ingested.transplacental transfer can occur.

Toxoplasma gondii

Toxoplasma gondii

Eukaryotic Parasites The Helminths

Cestodes = TapewormsTrematodes = Flukes

Nematodes = Roundworms

Ascaris lumbricoides life cycleRoundworm, dioecious.Both male and female worms.

Ascaris lumbricoides (nematode)

Ascaris lumbricoides eggs in fecal smear

Ascaris lumbricoides

Clonorchis sinensis life cycle(Oriental liver fluke-Trematode) Metacercariae are

cystlike and dormantand ingested. Maturationoccurs in smallIntestine.

Snail, intermediate host

Clonorchis sinensis worm

Clonorchis sinensis worm

Monoecious, have both maleand female sex organs.

Clonorchis sinensis eggs

Dipylidium caninum: Cestode, tapeworm, monoecious.

Dipylidium caninum – eggs (eggball)

Dipylidium caninum eggs

Dipylidium caninum scolex and proglottidsstrobilia, immature, mature and gravid.

Echinococcus granulosus – hydatid cysts tapeworm. Small, only 3 proglottids. Hydatid sand, cysts in infected tissue.

Echinococcus granulosus worm and eggs

Hooks on eggs for attachment

Echinococcus granulosus worm and eggs

Encysted scolices of Echinococcus granulosus in lung ("hydatid sand“)

Enterobius vermicularis (pinworm)Nematode, dioecious

Enterobius vermicularis (pinworm)

Enterobius vermicularis eggs

Enterobius vermicularis worms

Ancylostoma

Ancylostoma (hookworm), nematode.

Ancylostoma (hookworm)

Ancylostoma (hookworm)Burrows through skin, enters bloodstream and travels to lungs. Swallowed andEstablishes in intestine. Attaches and consumes host blood.

Ancylostoma eggs

Paragonimus westermani life cycle

Fluke, lung- Trematode, snail is intermediate host.

Paragonimus westermani lung fluke

egg

monoecious

Shistosoma mansoni (blood fluke) life cycle

Shistosoma mansoni (blood fluke) schistosomiasis

Schistosoma mansoni copulating pair

Schistosoma mansoni Schistosoma haematobium

Schistosoma spp. eggs

Spike or spine on egg for attachment

Strongyloides stercoralis life cycle

Strongyloides stercoralis adult and egg

Taenia solium life cycle, pig tapeworm

Taenia solium scolex

Taenia solium eggs

Taenia solium

Wuchereria bancrofti life cycle

Wuchereria bancroftimicrofilariae in blood smear

Wuchereria bancrofti - Elephantiasis

The End