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33 Cards in this Set
- Front
- Back
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how are Rickettsias stained?
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Giemsa stain, polychromatic stain
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what is the process for the Giemsa stain?
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smear air dried, fixed with absolute methanol for 5 minutes, dried again. cover with giemsa stain for 1 hr. rinse with 95% ethanol, dry
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what are the metabolic activities of Rickettsia?
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glutamate oxidation with oxidative phosphorylation
all AA must be preformed to make proteins cells walls leak enzymes and ATP, unusual permeability |
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what is the pathogenicity of of Rickettsiaceae?
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grow in the endothelial cells of the sm blood vessels, this leads to hyperplasia of these cells with localized thrombus formation, this obstructs blood flows and red blood cells escape into the surrounding tissue. Rickettsiae are seen in macrophages surrounding vascular lesions (vasculitis), cell lysis occurs result of rickettsial multiplication
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what are the clinical signs of a Rickettsial infection?
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petechial rash, stupor, shock
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what are the different ways that Rickettsia can be identified?
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Weil-Felix reaction (antibodies formed during infection cross-react with polysaccharide O antigens of certain proteus strains) OX-2, OX-19 (vulgaris), OX-K (mirabilis)
Direct fluorescent antibody testing |
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What are the two species in the Typhus group?
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Rickettsia prowazekii - epidemic
Rickettsia typhi - endemic |
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Describe the symptoms of R. prowazekii
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1-2 weeks post louse bite: rash on trunk and spreads to extremities, chill, fever, headache, exhaustion, rash becomes hemorrhagic; severe form of disease causes stupor and delirium
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How is R. prowazekii identified?
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+4 OX-19
+ OX-2 0 OX-K GP - rash on trunk spreads to extremities |
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What is Brill-Zinsser disease?
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latent infection of R. prowazekii
disease is mild, rash is absent, antibodies appear earlier, no OX-19 antibodies observed |
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What are the symptoms of R. typhi?
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rash on trunk spreads to extremities, headache, fever, chills, bacteria in cytoplasm.. mild, resolves itself
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How is R. typhi identified?
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+4 OX-19
+ OX-2 0 OX-K GP- severe lesions in testicles and swelling of scrotum |
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what disease is caused by R. rickettsii and what are the symptoms?
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Rocky Mountain Spotted Fever
rash appears on ankles, wrists, and forehead, spreads to trunk. fever, headache |
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how is R. rickettsii identified?
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+4 OX-19
+ OX-2 0 OX-K GP- fever, necrosis, skin ulcers, hemorrhagic rash in the scrotum |
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what type of ticks are vectors for RMSP?
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wood tick (dermacentor andersoni)
dog tick (dermacentor variabilis) |
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how is RMSP treated?
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tetracycline and chloramphenicol
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what organism causes tick typhus (Boutonneuse fever)?
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Rickettsia conorii
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what are the symptoms of Boutonneuse fever?
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causes a distinctive lesion called a tache noire- necrotic center and develops an eschar
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how is R. conorii identified?
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+ OX-19
+ OX-2 bacteria located in cytoplasm and nucleus GP- fever and swelling of scrotum |
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what organism causes Rickettsialpox? what is the vector of this organism?
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Rickettsia akari
blooding sucking mite- house mouse |
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what are the symptoms of Rickettsialpox?
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mild disease, primary lesion is an eschar at the bite site, followed by fever, chills, enlarged lymphnodes and a rash similar to chickenpox
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How is R. akari identified?
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bacteria found in cytoplasm and nucleus of animal cells
no reaction to any of the OX antigens in the Weil-Felix GP- fever and swelling of scrotum |
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what organism causes scrub typhus? what is the vector of this organism?
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Orienta tsutsugamushi via chiggers
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what are the symptoms of scrub typhus?
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eschar at the bite site, chills, fever, headache, rash, enlarged lymphnodes, rash of trunk spreads to extremities
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how is O. tsutsugamushi identified?
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bacteria located in cytoplasm
+4 OX-K |
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what disease is caused by Coxiella burneti?
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Q fever
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what sets C. burneti apart from other rickettsias?
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it can survive outside the host cells
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what is the pathogenesis of Q fever?
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aquired by inhaling dusts near cattle , sheep, goats. onset is abrupt, chills and fever but no rash, resembles atypical pneumonia
C. burneti grows in the phagolysosome GP- fever treatment- tetracycline |
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what causes trench fever and what are the symptoms?
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Rochalimaea quintana
human body lice abrupt onset, chills fever, rash, splenomegaly, myalgias |
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how is Rochalimaea quintana identified?
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negative OX rxn
catalase - oxidase - urease - |
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what disease is caused by Rochalimaea henselae?
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cat scratch fever
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what organism causes oroya fever (hemolytic anemia) and verruga peruana (eruption of skin nodules)?
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Rochalimaea bacilliformis
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what is Ehrlichiosis?
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potomic horse fever
caused by dog tick (Ehrlichia canis) fever, anemia, bleeding from capillaries |
