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Parasit Lab Quiz 2-1

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dslemeraldcity's version from 2016-09-09 11:29

Intro to Hemoflagellates

Question Answer
why is it so hard to develop a vx for trypanosomes?they are PLEOMORPHIC, and change their morphologic form based on the host they are in
how do trypanosomes reproduce?binary fission
which form of the trypanosome is found in insects? mammals?Insects= epimastigote. Mammals=trypomastigote
what is an epimastigote? ("Metacyclic" Trypomastigote)the form of the trypanosome found in insects (the intermediate host)
what is a trypomastigote?the extracellular form of the trypanosome found in mammals
what is an amastigote?the intracellular form of trypomastigote found in mammals. Characterized by not having an exterior flagella or cilia.
what is a promastigote?developmental stage of epimastigote. The motile, elongated, extracellular form in the life cycle that is characterized by a single anterior flagellum and no undulating membrane found in sand flies.
What is a parabasal body?Structure from which the flagellum originates
What is a Kinetoplast?An extension of the mitochondria. Contains DNA. Lies adjacent to the parabasal body.
Morphology Labeled
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Stercorarian Trypanosomes (T. cruzi)

Question Answer
Where does the Trypanosome cruzi reproduce?Asexually in the vector's gut & develops in the posterior portion of the alimentary tracts of IH (Intermediate Host) and is shed in it's feces
How is T. cruzi transmitted?From the vector (Kissing Bug) carrying the parasite's feces. The fecal matter contains the “metacyclic” trypomastigote (infective for the definitive host) gets rubbed into the eye or left in the bite wound of the DH.
T. cruzi is aka, and causes?aka Chaga's Disease. Trypanosomiasis
how can an animal be infected with T. cruziparasite lives in the gut of a kissing bug, kissing bug poops on you and bites you
Intermediate Host?Kissing Bugs (Triatome)
Definitive Host?All Mammals including humans. ZOONOTIC
Reservoir HostShelter dogs, opossum, skunks, rodents, bats.
Life Cycle of T. cruzi?Type: Indirect. Cycle: vector (usually kissing bug) bites host, and defecates, depositing metacyclic trypomastigote, enters bloodstream, nn tissue, mm tissue, transforms into trypomastigote (looses flagella), enters cells, reproduces as amastigotes, cell dies & releases amastigotes. Some amastigotes infect new cells, while others transform into trypomastigotes & remain in bloodstream. New Vector (Intermediate Host-Kissing Bug) bites mammal & ingests either the amastigote or trypomastigote from the bloodstream. T. cruzi now reproduces asexually in the IH Vector's (Kissing Bug's) gut & further develops in the posterior portion of the alimentary tract. The trypomastigotes transform into metacyclic trypomastigotes & is shed in the IH's feces.
T cruzi amastigotes really like _____ ________ tissue and cause ___________?Cardiac muscle; Cardiomyopathy
What another ways can T cruzi be picked up? 1. Eating Kissing bug or it's feces 2. Vector contamination of existing wounds 3. Ingestion of tissues of wild reservoir hosts 4. Transplacentally or transmammarily 5. Blood transfusions & tissue transplant
What are the Clinical Signs in People? Animals?CHAGOMA- Inflammatory Lesion at the Site of infection due to initial organism reproduction in tissue. ROMANA'S SIGN- Palpebral edema And Conjunctivitis (usually Unilateral), similar idea to chagoma but organism rubbed in eye.
Acute (Dogs)- Fatal myocarditis
Chronic infection (Dogs)- Dilated Cardiomyopathy and ventricular arrhythmias
Others- CNS signs, acute diarrhea, lymphadenopathy, fever and anorexia
Diagnostic Techniques?1. Stained Blood smears 2. Xenodiagnosis (Diagnosis based on recover of trypanosome from bugs that have fed on the person or animals) 3. Tissue Cultures 4. ELISA, IFAT, Complement fixation 5. Radioimmunoprecipitation (RIPA) Assay 6. PCR 7. Immunohistochemistry
Images of Trypanosome cruzi & its Clinical Presentation in Humans
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Trypanosoma Equiperdum

Question Answer
What is Trypanosoma equiperdum cause? What does it mean? And who does it infect?Dourine. It means "unclean" in Arabic. Affects the horse, donkey & mule.
How is it transmitted?Direct-Venerally (SEXUALLY TRANSMITTED) Mostly from stallion to mare. No IH or evidence that arthopod vectors play a role. (transmitteed transplacentally or transmammary RARE)
Where is Trypanosoma equiperdum found?Animals can be non-infectious for weeks/months (some strains more virulent than others) as the parasite disappears from the genital tract. Found in genital secretions & as amastigotes intracellularly when they reproduce.
Is this a reportable or non-reportable dz?REPORTABLE
What are the symptoms of Trypanosoma Equiperdum?Silver dollar plaque lesions, Edematous, circular flattened patches on skin! PATHOGNOMONIC! (a specific characteristic, indicative of a particular disease or condition). Lasts for 3-7 days, but not seen in all strains. 50-70% mortality rate if left untreated. Genital Edema, Mucopurulent Discharge & some CNS signs.
What must you do BEFORE collecting samples when this is suspected?CONTACT THE AUTHORITIES; then collect samples & send it under secure conditions to APPROVED AUTHORIZED LABS ONLY
Diagnostic techniques?Serum, whole blood in EDTA, and blood smears (difficult to find in other bodily fluids.)
What happens with the animals that are suspected of having Trypanosoma Equiperdum? What about confirmed cases? Suspected: Quarantined, until confirmed negative; Confirmed cases are euthanised!
Image of Trypanosoma equiperdum & the Pathognomonic Silver Dollar Plaques
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Leishmania

Question Answer
What is the Intermediate Host for Leishmania? Vector?Sandflies (IH), Vector-Fleas?
Morphology Life Stage?Promastigotes instead of Epimastigotes . No Trypomastigotes
What is the Definitive Host for Leishmania?Humans & Dogs ZOONOTIC
What is the Life Cycle of Leishmania?1. Indirect 2. Sandflies are the intermediate host 3. Transmission via blood transfusions are possible 4. Fleas may be biological vectors 5. Prolonged incubation period of months to years 6. Insect bites host and acquires amastigotes 7. Amastigotes go to midgut and differentiate into promastigotes 8. Promastigotes multiply in the midgut of the sandfly and migrate to the foregut and cause blockage 9. Insect bites host (mammal) and regurgitates promastigotes (WTF?!) 10. Promastigotes enter blood stream of host and invade macrophages 11. In macrophages they differentiate into amastigotes 12. Amastigotes multiply intracellularly until host cell bursts 13. Amastigotes are released and infect more cells
What is special about Leishmania vs other parasites we have studied so far?they have a prolonged incubation period - lots of travel time through the body -
What are the 3 Clinical Forms of Leishmania? Which can be fatal?Diffuse Cutaneous, Mucocutaneous, Visceral; Visceral can be fatal
Explain what Diffuse Cutaneous Leishmania is all about.This is an immune mediated process due to extensive, non-protective immunoglobulin response resulting in immune-complex deposition that causes vasculitis, arthritis and thrombocytopenia.
What does Diffuse Cutaneous Leishmania look like?Seen in dogs, cats & humans as multiple rounded alopecic skin lesions on the pinna, ear, muzzle & footpads. Dermatitis (non-ulcerative nodules "COMEDONES" & plaques that dissemination from a localized lesion.) Hair Coat become brittle & depigmentation is common. Slow Chronic progression.
What does Mucocutaneous Cutaneous Leishmania look like?Seen on dogs, rodents & wild animals as Ulcers & Sloughing of cartilaginous tissues (nose)
What does Visceral Cutaneous Leishmania look like?a. Can be fatal/poor prognosis b. Progressive systemic disease c. Transplacental transmission has been reported d. In Dogs- Chronic wasting, exercise intolerance, anorexia, lameness, lymphadenopathy, epistaxis, non-regenerative anemia, non-pruritic skin lesions
How do we diagnose Leishmania?Dogs --> Skin scrapings from the periphery of skin ulcers on the pinna of the ear, muzzle & footpads; Amastigotes seen in Spleen, Lymph nodes, Bone marrow, Liver, Blood Smears of peripheral blood Montenegro test, Leishmania antibody test (ELISA), PCR, Western Blot, IFAT
How does a Montenegro Test work?Leishmania Skin test - Administration followed by recheck in 3 days (Similar to human TB test). Inject dead promastigotes (Delayed type hypersensitivity) => Look for erythematous cutaneous response
How do we treat Leishmania?Amphotericin B (but relapses are common), Controlling/preventing Leishmania is better; Leishmune Vax, topical insecticide (pyrethrins), Scalibor collars.
Images
(Amastigote in Macrophage of a Mammal) (Promastigotes from Midgut of Sandfly)
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