Mycobacteria Flashcards
What test is done to identify Mycobacteria within bacilli?
Ziehl-Neelsen
Give examples of conditions caused by mycobacteria
Tuberculosis, leprosy, buruli ulcers
How many deaths from TB in the last 200 years
1 billion
Mycobacteria are slightly c____, beaded bacilli
curved
Mycobacteria are resistant to Gram stain due to the high ____ content with mycolic acids in cell wall
lipid
True of false: mycobacteria are anaerobic
False, they are aerobic
Mycobacteria have high molecular weight cell ___
wall
True or false: mycobacteria eg M. tuberculosis are fast growing
False, they are slow growing (makes much longer to diagnose)
The thick ____ rich cell wall makes immune cell killing and penetration of drugs challenging
lipid
How is TB transmitted?
Through the air from one person to another
What is primary tuberculosis?
Initial contact made by alveolar macrophages with the bacilli taken in lymphatics to hilar lymph nodes
Latent TB
T-cell mediated immune response, primary infection contained, no clinical disease
Pulmonary TB
Granulomas form around bacilli in apex of lung
More air and less perfusion in apex so fewer WBCs
TB may spread in lung causing other lesions
(Could happen immediately or months later after primary infection)
Name other types of TB when it spread beyond the lungs
TB meningitis
Miliary TB
Pleural TB
Bone and joint TB
Genito urinary TB
Mycobacteria are phagocytosed by _____ and traffic to phagolysosomes
macrophages
Mycobacteria escape into the cytosol due to adaptions to withstand the p_______ killing
phagolysosomal
CD4 T-cell generate interferon g____ which helps activate macrophages to undergo intracellular killing
gamma
The TB uses ______ as a Trojan horse to pass to other areas of the body
macrophages
Working granulomas
Mycobacteria shut down metabolically in order to survive (become dormant)
Failing granulomas
Forms a cavity of live mycobacteria and eventual disseminated disease
What does the granuloma consist of?
Macrophages and Th1 lymphocytes (which synthesises IFN-gamma and other cytokines)
Granulomas can become unstable by depletion of what 2 components?
CD4 and TNFa
Anti-Tb drugs
2 months -Isoniazid, rifampicin, pyrazinamide, ethambutol
Followed by 4 months of just isoniazid and rifampicin
How does injury activate WBCs?
Loss of blood causes hypoxia
