Parasites--Protozoans Flashcards
List Protozoans based on:
- GI infection
- CNS infection
- Hematologic infeciton
- Visceral infection
- STDs
- -giardia
- entamoeba
- cryptosporidium - -toxoplasma (from cats)
- trypanosoma (not cruzi) (african sleeping sickness)
- naegleria fowleri - -plasmodium (malaria)
- babesia - -leishmania
- trypanosoma cruzi (chagas’ disease) - -trichomonas
List protozoans based on:
- apicomplexan
- kinetoplasmid
- plasmodium, babesia, cryptosporidium, toxoplasma
2. leishmania, trypanosoma
Apicomplexans
- life cycle
- morphology
-alternate btwn asexual (schizogony) and sexual (sporulation) repro.
Malaria: Sporozoites from mosquito saliva infects liver cells, then multiplies. The cell bursts, releasing merozoites. Merozoites infect blood cells, becoming trophozoites, which multiply through schizogony, becoming a schizont. The schizont (RBC) bursts, releasing more merozoies. Gametocytes are also made, so that they can enter a mosquito and undergo sexual repro.
-special apical organelles for cell invasion
Entamoeba histolytica
- transmission
- disease/symptoms
- diagnosis
- ingestion of cysts in water, fecal-oral
- causes Amebiasis/amoebic dysentery. Rarely, can invade body to liver or lungs
- cysts in stool, trophozoites and cysts in bloody diarrhea because trophozoites contain RBCs
Giardia lamblia
- transmission
- disease/symptoms
- diagnosis
- drinking water, cysts
- fatty diarrhea
- cysts in stool
Apicomplexans: what animal is the sexual cycle?
- cryptosporidium
- toxoplamsa
- plasmodium
- babesia
- humans
- cats
- mosquitoes
- ticks
Cryptosporidium
- transmission
- disease/symptoms
- diagnosis
- ingestion of cysts in water
- diarrhea, severe in AIDS
- cysts in stool (cup and saucer)
Toxoplasma
- transmission
- disease/symptoms
- diagnosis
- ingestion of cysts, cat feces. Can travel to muscle, brain
- acute toxoplasmosis affects fetuses (birth defects, stillbirth) and AIDS. latent affects AIDS
- serology–immunoflourescence (test for antibodies)
Babesia microti
- transmission
- disease/symptoms
- diagnosis
Babesiosis
- ticks transmit sporozoites. Trophozoites invade RBCs, forming merozoites.
- hemolytic anemia, flu-like symptoms. also may be asymptomatic
- blood microscopy to look at RBCs (“maltese cross” of merozoite distinguishes from malaria)
Plasmodium
- transmission
- disease/symptoms
- diagnosis
Malaria
-mosquitoes transmit sporozoites. Liver cells invaded, merozoites released. Become trophozoites when invading RBC. Schizont formed, more merozoites released upon cell burst.
- Hemolytic anemia, chills, splenomegaly. Cerebral malaria in extreme cases of P. falciparum only. Respiratory distress syndrome by inflammation of lungs.
- blood stain microscopy, look at RBCs
Plasmodium immunity?
Resistance to malaria is acquired very slowly, with resistance to severe disease occuring first. Resistance is usually incomplete–immunity is lost over time if not reinfected. This is important for immigrants that return home after having left for an extended period of time.
How have humans evolved in response to malaria?
- sickle cell trait–immune
- G6P DH deficiency–immune
- Duffy blood group negative–RBC receptor for certain malaria strains lacking.
Leishmania
- transmission
- disease types
- symptoms
- diagnosis
- sandfly transmits promastigotes into skin. Macrophages phagocytize them, but they transform into amastigotes inside macrophages. Amastigotes multiply in various tissues. Sandfly ingests macrophages infected with amasigotes, which transform back into promastigotes in sandfly.
- cutaneous, mucocutaneous, visceral.
- Skin ulcers, possible hepatosplenomegaly
- biopsy lesion, look for amastigotes
Kinetoplastid morphological forms:
- amastigote – no flagella
- promastigote
- epimastigote
- trypomastigote
Trypanosoma brucei
- transmission
- disease/symptoms
- diagnosis
African sleeping sickness
- Tsetse fly transmits trypomastigotes into blood, which multiply in CNS and other areas.
- CNS infection, coma
- direct blood/lymph/CSF examination
