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19 Cards in this Set
- Front
- Back
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Gram stain |
"gram ghost" - acid fast so resistant to decolourisation by acid. Ziehl neison stain can be used |
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Haemolytic or not |
Haemolytic |
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Catalase positive or not |
Catalase positive |
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Shape |
Bacillus |
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Intracellular or extracellular |
Facultative intracellular |
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How much of the population is infected by latent TB |
1/3 |
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How is tuberculosis transmitted |
Coughing, sneezing, inhalation, aerosol |
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What cell types does tuberculosis infect |
Macrophages, alveolar macrophages |
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Primary infection usually occurs where? Reactivated infection occurs where? |
Primary - lower lungs Reactivated - upper lungs, as more O2 and ventilation |
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What is miliary TB |
When TB becomes disseminated to the brain, kidneys and bone |
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What are symptoms of TB |
Night sweats, anorexia, swollen throat, weight loss, coughing, coughing blood In 90% of cases tb is restricted to lungs Extrapulmonary tb/miliary TB - when infection spreads outside lungs, in immunocompromised. |
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How is TB diagnosed |
Physical examination - enlarged lymph nodes Tuberculin skin test - false positive in immunised ppl Quantiferon test - high specificity for latent tb PepCT scan or chest radiograph Interferon gamma release assays - blood test for latent tb |
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What is the drug treatment for TB |
RIPE rifampin Isoniazid Pyramzinamide Ethambutol |
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What drug is used for drug resistant tb |
Clofazamine |
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Is there a vaccine for tb? If so what's it called and what type of vaccine is it |
Yes BCG vaccine (bacilli calmette guerin) Live attentuated |
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What are some virulence factors of TB |
Catalase peroxidase - resists host cells oxidative response ESTAT6 - down regulation of MHC1 on host cells surface trehalose dimycolate/cord factor - triggers toxicity in animal models, TNF leads to granuloma formation, prevents Sulfatides - prevent phagosome lysosome fusion LAM - induces cytokines and resist host oxidative stress, prevents phagosome maturation Mycolic acid - present in cell envelope?? Research |
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What is the immune response to tb |
- TB enters alveolar macrophages - TB kills macrophage after replicating, spilling TB into the lungs - th1 response and cd4 t cells release interferon gamma - T4 hypersensitivity reaction - granuloma formation |
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What is a ghon focus |
The necrotic cells that form in a granuloma which encases tb - known as caseous necrosis |
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What is a ghon complex |
Ghon focus plus hilar lymph node often leading to fibrosis and calcification - which is a ranke complex |
