Lab Practical Final - Eukaryotic Parasitic Infections Flashcards
Giardia lamblia:
Transmission:
Diagnosis:
Kingdom:
- Giardia lamblia: “smiley face” and balloon like; flagellated; most common waterborne disease in U.S.
- Transmission: fecal-oral contamination
- Diagnosis: trophozoites in fecal smears
- Kingdom: Protista
Malaria Genus: Species: Transmission: Diagnosis: Kingdom:
- Genus: Plasmodium
- Species: P. falciparum, P. vivax, P. ovale, P. malariae
- Transmission: mosquitoes
- Diagnosis: parasite present in RBCs
- Kingdom: Protista
Naegleria fowleri: PAM: Transmission: Diagnosis: Kingdom:
- Naegleria fowleri: circle with rings; blob; developed shape with flagella
- PAM: Primary Amebic Meningoencephalitis
- Transmission: nasal passages; lakes, pools, tap water
- Diagnosis: trophozoites in CSF and tissue
- Kingdom: Protista
Trypanosoma cruzi:
Transmission:
Diagnosis:
Kingdom:
- Trypanosoma cruzi: “Chagas disease”
- Transmission: triatomine bug
- Diagnosis: trypomastigote form in the blood (NOT in the cells)
- Kingdom: Protista
Toxoplasma gondii:
Transmission:
Diagnosis:
Kingdom:
- Toxoplasma gondii: cresent shaped tachyzote
- Transmission: eating undercooked meat of animals with tissue cysts, fecal-oral contact with cat feces, blood transfusion or transplacentally
- Diagnosis: tissue biopsy (cysts), bloodwork (tachyzoites), or DNA in amniotic fluid
- Kingdom: Protista
Trichomonas vaginalis:
Transmission:
Diagnosis:
Kingdom:
- Trichomonas vaginalis: common STD
- Transmission: sex
- Diagnosis: trophozoites in vaginal and prostatic secretions
- Kingdom: Protista
Taenia: Species: Transmission: Diagnosis: Kingdom:
- Taenia: tapeworm; suckers and proglottids (eggs)
- Species: saginata (cattle), solium (pigs), pisciformes (dogs/cats)
- Transmission: eating raw/undercooked meat
- Diagnosis: eggs (proglottids) in feces 3 months after infection
- Kingdom: Animalia
Toxocara canis:
Transmission:
Diagnosis:
Kingdom:
- Toxocara canis: round worm; nematode parasite
- Transmission: accidental ingestion of eggs in soil or host organism
- Diagnosis: presumptive based on anatomical and epidemiology diagnosis, or by presence of other nematode parasite eggs in feces
- Kingdom: Animalia
Exo-Erythrocytic Schizogony Cycle of Malaria:
mosquito takes blood & injects sporozoites > sporozoites infect liver cells > and they mature into schizonts > which rupture and release merozoites > parasites undergo asexual multiplication in the erythrocytes (next: erythrocytic cycle)…
Erythrocytic Schizogony Cycle of Malaria:
merozoites infect RBCs > the ring stage trophozoites mature into schizonts, which rupture releasing merozoites > some parasites differentiate into sexual erythrocytic stages (gametocytes) > blood stage parasites are responsible for the clinical manifestations of the disease > next: sporogonic cycle)…
Sporogonic Cycle of Malaria:
the gametocytes (male = micro and female = macro) are ingested by an Anopheles mosquito during a blood meal > the parasites’ multiplication in the mosquito is known as the sporogonic cycle > while in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes > the zygotes in turn become motile and elongated (ookinetes) > which invade the midgut wall of the mosquito where they developed into oocysts > the oocysts grow, rupture, and release sporozoites > which make their way to the mosquito’s salivary glands > inoculation of the sporozoites into a new human host perpetuates the malaria life cycle.
Human stages in Trypanosomiasis:
An infected triatomine insect vector (“kissing” bug) take a blood meal and releases trypomastigotes in its feces near the site of the bite wound > trypomastigotes enter the host through the wound or through intact mucosal membranes (such as the conjunctiva) > common triatomine vector species: triatoma, rhodnius, panstrongylus. Inside the host, the trypomastigotes invade cells near the site of inoculation, where they differentiate into intracellular amastigotes > amastigotes multiply by binary fission > and differentiate into trypomastigotes, and then are released into the circulation as bloodstream trypomastigotes. > Trypomastigotes infect cells from a variety of tissues and transform into intracellular amastigotes in new infection sites.
- Clinical manifestations can result from this infective cycle.
- The bloodstream trypomastigotes do not replicate (different from African trypanosomes)
- Replication resumes only when the parasites enter another cell or are ingested by another vector
Triatomine bug stages in Trypanosomiasis:
the kissing bug becomes infected by feeding on human or animal blood that contains circulating parasites > the ingested trypomastigotes transform into epimastigotes in the vector’s midgut > the parasites multiply and differentiate in the midgut > and differentiate into infective metacyclic trypomastigotes in the hindgut.
Neglected parasitic infections in the US…
- Chagas disease (trypanosomiasis)
- Neurocysticerosis (by tania solium)
- Toxocariasis
- Toxoplasmosis
- Trichomoniasis
Infections in which humans are dead end hosts:
- Naegleria
- Toxocariasis
- Toxoplasmosis
Infections in which humans are part of the life cycle:
- Giardiasis
- Malaria
- Trypanosomiasis
- Taeniasis
- Trichomoniasis
