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12 Cards in this Set
- Front
- Back
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TB (key points)
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*most common manifestation of disease by M. tuberculosis is PNEUMONIA
--characterized by persistent cough, bloody sputum, weight loss, fevers, night sweats --subacute/chronic to other types of pneumonia |
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TB Bacteriology
(acid fast stain or fluorescent stain using auramine or rhodomine) |
slim gram positive organism
beaded rod appearnce non motile, non spore forming acid fast - bind to high lipid *Mycolic Acid (lipids) -may inhibit innate immune Lipoarabinomanan (sugars) -similar to LPS, ability to cause disease Polypeptides (PPD) -induces DTH |
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TB Growth Characteristics
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slow growing (12-24 hr)
RICH media = lowenstein-Jensen w/ has eggs and special dyes looks dry and flaky in culture solid media = 8 weeks *low recovery rate (40%) liquid media = 10-12 days *high recovery rate (90%) |
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Weapons of Pathogen
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logarhytimcally replicates w/in non-activated macrophage
multiples extracellularly in liquefied caseous material |
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Transmission and Infection
(th1 response = KILL organism) (latent infection always ready if immune system drops) |
aerosol transmission by droplets (<5 microns)
local tissue response of GRANULOMA in lower airway an alveoli |
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Primary INfection
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in 25-50% of exposed, CMI is induced and =
1. 85% no disease - latency 2. 15% disease - early vs late early- 5% late reactivation- 10% 3. tuberculoma and meningitis a serious primary disease 4. Pott's Disease- TB of spine w/ para-spinous abscess |
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Diagnostic Tools
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Tuberculin Skin Test
-reflection of immune response Blood Assay of IFN-gamma -more specific than TST, no cross reaction with BCG vaccine Chest Xray- lung pneumonia is most common disease presentation |
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TB treatment
(MDR resistant to INH) (XDR resistant to INH, Rifampin, Fluoroquinolone, and at least one injectable second line drug) |
prolonged therapy, 6 month minimum AB w/ multiple drugs and for latent treat w/ one drug for 9 months
Isoniazid (inhibits mycolic acid synthesis) Rifampin (inhibits RNA polymerase) Pyraxinamide (unknown) Ethambutol (inhibit cell wall synthesis) Streptomycin (inhibit protein synthesis) |
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M. Leprae
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acid fast bacillus
armadillo is host grows in schwaan cells and macrophages Immune response = 1. lepromatous - strong humoral response + weak CMI 2. tuberculoid - strong CMI and weak humoral |
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M. Leprae Dx and Tx
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AFB on tissue specimens
Granuloma on tissue Lepromin skin test treat - similar to TB Tuberculoid - 6 months w/ rifampin and dapsone Lepromatous - 1 yr w/rifampin, dapsone, clofazamine |
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M avium complex
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NTM
-water and soil most common 1. children = lymphadenopathy 2. chronic lung disease 3. disseminated disease in HIV co-infected patients |
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M marinum
(divers, aquarium, pools) |
found in salt and fresh H20
granuloma on extermities likes cool temps |
