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41 Cards in this Set
- Front
- Back
What is the relevant taxonomy for malaria?
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Phylum Apicomplexa
Class Aconoidasida |
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What is the common structure for all apicomplexa?
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apical complex
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What is different about malaria's apical complex?
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there is no conoid in malarial parasites - aconoid.
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What is the world ranking for malaria infections?
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ranks as 6th most common in the world
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What is the definitive host for malaria?
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mosquitoes - Anopheles
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How is the Plasmodium transferred to humans?
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female Anopheles blood meal
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How do Anopheles track humans?
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they follow a CO2 trail and then finally there is attack is visual based. they land and project mouth parts into superficial arteries for blood meal.
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Cinchona
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bark of this tree was used in the 1600s to treat malaria as a result of Quinine containing alkaloids in the Cinchona bark
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mefloquine
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synthetic quinine used to treat malaria even today
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What are the four species of malaria we should concern ourselves with?
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1) P. vivax - 80% of malaria
2) P. falciparum - 50% of all tropical forms 3) P. malariae - 7% of malaria 4) P. ovale - least common |
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What is the most virulent and fatal form of malaria?
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P. falciparum
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What two malaria strains have hypnozoites?
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P. vivax and P. ovale
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hypnozoites
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relapsing fever causing form of pathogen that lays dormant and reactivates at a later time
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What strain of malaria can stay with you your entire life?
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P. malariae
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What form of malaria can infect humans and chimps?
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P. malariae
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What is the 12 step lifecycle of malaria causing organisms?
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The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host 1.
Sporozoites infect liver cells 2 and mature into schizonts 3, which rupture and release merozoites 4. (Of note, in P. vivax and P. ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks, or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony A), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony B). Merozoites infect red blood cells 5. The ring stage trophozoites mature into schizonts, which rupture releasing merozoites 6. Some parasites differentiate into sexual erythrocytic stages (gametocytes) 7. Blood stage parasites are responsible for the clinical manifestations of the disease. The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal 8. The parasites’ multiplication in the mosquito is known as the sporogonic cycle C. While in the mosquito's stomach, the microgametes penetrate the macrogametes generating zygotes 9. The zygotes in turn become motile and elongated (ookinetes) 10 which invade the midgut wall of the mosquito where they develop into oocysts 11. The oocysts grow, rupture, and release sporozoites 12, which make their way to the mosquito's salivary glands. Inoculation of the sporozoites 1into a new human host perpetuates the malaria life cycle. |
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merogony
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Multiple fission to produce merozoites.
Some references equate merogony and schizogony. |
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meront
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Asexual stage in the life cycle of some protozoa that undergo merogony to form merozoites.
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merozoite
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Daughter cell resulting from merogony.
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schizogony
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Form of asexual reproduction in which multiple mitoses take place, followed by simultaneous cytokinesis, resulting in many daughter cells at once.
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schizont
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Cell undergoing schizogony, in which nuclear divisions have occurred but cytokinesis is not completed; in its late phase sometimes called segmenter. Daughter cell resulting from schizogony.
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In general what are merogony, sporogony, and gametogony?
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types of schizogony.
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sporogony
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Multiple fission of a zygote; such a cell is also called a sporont.
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sporont
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Undifferentiated cell mass within an unsporulated oocyst.
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sporozoite
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Daughter cell resulting from sporogony.
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chloroquine
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one of the first effective anti-malarial drugs but to which malarial organisms developed resistance
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pyrimethamine
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particularly useful in choloquine-resistant P. Falciparum
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mefloquine
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most common, even today, in treatment. used for prevention and treament.
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primaquine
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works against gametocytes and hypnozoites
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doxycycline
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used today because it is cheap used a lot in combination with quinine
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two body forms of giardia
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1) cyst form (outside of the body, which is transmitted between hosts)
2) motile trophozoite (four pair of flagella) |
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giardia phylum
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Retortamonada
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defining characteristics of giardia
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1) no mitochondria or golgi
2) 4 pairs of flagella 3) axoneme |
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mastigont vs. karymastigont in giardia
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mastigont - axoneme w/ basal fibers
karymastigont - location of axoneme with basal fibers is relative to the nucleus, kary = nucleus |
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giardia nucleus arrangement
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two nuclei lying side by side
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where are giardia found in humans?
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intestines of humans most common
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What are the 4 common species of giardia found in mammals?
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G. duodenalis = G. intestinalis = G. lablia = G. muris
they are all the same, but be aware of the different names! |
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giardiasis transmission
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travelers disease
beaver fever! poor sanitation cysts are transmitted in feces |
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giardiasis symptoms
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The most common symptoms of infection include diarrhea of greater than 10 days duration, abdominal pain, flatulence, bloating, vomiting and weight loss.
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5 step lifecycle of giardia transmission
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1) The cysts are hardy, can survive several months in cold water. Infection occurs by the ingestion of cysts in contaminated water, food, or by the fecal-oral route (hands or fomites).
2) In the small intestine, excystation releases trophozoites (each cyst produces two trophozoites). 3) Trophozoites multiply by longitudinal binary fission remaining in the lumen of the proximal small intestine where they can be free or attached to the mucosa by a ventral sucking disk. 4) Encystation occurs as the parasites transit toward the colon. The cyst is the stage found most commonly in non-diarrheal feces. 5) Because the cysts are infectious when passed in the stool or shortly afterward, person-to-person transmission is possible. |
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giardiasis tx
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Metronidazole is the golden ticket
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