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18 Cards in this Set
- Front
- Back
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pleomorphic gram neg bacteria that are obligate intracellular parasites
- why obligate? |
1. Chlamydia
2. Rickettsia energy parasites--have an ATP/ADP translocator to take host's ATP ....still considered bacteria bc have RNA & DNA, ribosomes, and abx sensitivity ...can't culture on media!! need to use living cells! |
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chlamydia and rickettsiae gram stain
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pleomorphic gram negative, very small
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severe cervical motion tenderness
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"Chandelier sign" --leap up to chandelier
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Chlamydia
- labs - unique characteristics |
gram neg but INTRACELLULAR --> cyctoplasmic inclusions on Giemsa or Ab-stained smear
no peptidoglycan layer --> why PCN ineffective obligate intracellular- takes ATP from host 1) Elementary Body- small, inert, Enters cell via endocytosis 2) Initial body = Reticulate body--replicates in cell by fission |
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Chlamydia species that cause disease in humans
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1. Chlamydia trachomatis
2. Chlamydophilia pneumoniae 3. Chlamydophilia psittaci |
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Chlamydia tachomatis
- diseases - important serotypes |
1. Types A, B, C:
Trachoma --> leading cause of preventable blindness; develops over 15 years Africa/Blindness/Chronic infection 2. Types D-K: - Urethritis/cervicitis/PID - Inclusion conjunctivitis (usualy neonates) - Neonatal pneumonia 3. Types L1, L2, L3: Lymphogranuloma venereum - painLESS bump/ulcers which heals - then painLESS swollen LN's (may break/drain pus) ...also Reiter's syndrome (inflammatory/reactive arthritis) |
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chlamidae which cause pneumonia
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1. Chlamydophilia psitacci
- BIRDS! - "psittacosis" 2. Chlamydophilia pneumoniae - transmitted person to person via respiratory route |
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what Rickettsia does NOT require an arthropod vector?
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Coxiella burnetii --> inhaled aerosols --> Q fever
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Rickettsia
- basics - how different from chlamydia |
- gram neg
- obligate INTRACELLULAR (steals ATP, CoA, NAD) replicates freely in cytoplasm (chlamydia replicates in endosomes-inclusions) |
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traditional lab test for Rickettsia
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Weil-Felix test
mix pt's serum with cross-reacting antigens from Proteus vulgaris (Ox-2, OX-19, OX-K) |
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Rocky Mountain spotted fever
- cause - sx - tx |
Rickettsia rickettsii
- fever - h/a - rash tx = doxycycline |
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Rickettsial disease caused by mites
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Rickettsia akari are transmitted by mites which lives on house mice
--> rickettsialpox - mild, self-limited - fever - papule at site of bite --> vesicle - other vesicles over body tx = doxycycline |
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Typhus
- cause - vector - reservoir |
1. Epidemic
- Rickettsia prowazekii (Pro-war! overcrowding, Napolean's army) - vector = lice - reservoir = FLYING SQUIRREL in southern U.S. - sx: abrupt fever, h/a --> rash, may get gangrene, occasionally fatal 2. Endemic - Rickettsia typhi - vector = flea - reservoir = rodents - similar sx but less severe |
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Bartonella
-spp -characteristics -diseases |
very similar to Rickettsia (gram neg) but NOT obligate intracellular
1. Bartonella henselae Cat-scratch disease cat bite/scratch --> regional LNs swell, low grade fever/malaise --> resolves in a few months! 2. Bartonella quintana Trench Fever vector = louse --> fever, h/a, back/leg pain --> multiple relapses (often after 5d -- quintana) but fatality rare both bartonellas can also cause bacteremia, endocarditis, angiomatosis in AIDs pts |
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cat-scratch disease
- cause - sx |
Bartonella henselae
cat scratch/bite --> regional LNs swell, low grade fever, malaise --> resolves in a few months |
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what does Coxiella burnetti cause?
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Q fever
(also granulomatous hepatitis, culture negative endocarditis) |
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Q fever
- bug - class - unique characteristics - sx |
Coxiella burnetti
a Rickettsia but different because: - it has an endospore form which extends survival outside host cell - grows in ticks & cattle--spores stay on hides, placentas --> human inhalation (NON-ARTHROPOD TRANSMISSION) -inhalation --> pneumonia but NO RASH!! (the only Rickettsia -- pneumonia) sx- abrupt fever, soaking sweats |
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Ehrlichiosis
- causes - vector - types - family |
1. Ehrlichia chaffeensis
--> Human Monocytic Ehrlichiosis (HME) 2. Anaplasma phagocytophilum --> Human Granulocytic Anaplasmosis (HGA) 3. Ehrlichia ewingii ....in Rickettsia family vector = tick |
