Tuberculosis Flashcards
what are 3 factors essential for its rapid spread
- crowded living conditions
- population with little innate resistance
- extremely clean conditions
TB is second to what disease as a cause of death resulting from a single infectious agent
HIV
what is the extrapulmonary form of TB
target monocytes, circulate blood, then goes everywhere
how fast does M. tuberculosis grow? what does this cause
slow-growing
chronic infection
how is TB transmitted
inhalation or ingestion
what are the 2 forms of TB
primary
seconday
what causes secondary TB
reactivation of dormant organisms
what damage happens in primary form
formation of granulomas followed by ceseation
for an immunocompromised individual what damage happens in the primary form
proceeds to miliary BTB
what causes occurs in secondary form
delayed-type hypersensitivity reaction ( Type IV hypersensitivity)
why in secondary TB does it occur in middle or upper lobe
TB is obligate aerobic
most oxygen in upper/middle lung
what is found in miliary TB
white nodule made of miliary foci of TB
what is located in the cell wall? what is the importance of it
wax
-need lots of energy to make it, slow growing
how can you see TB under microscope
rhodamine-auramine fluorescent dye
what color does TB show in fast acid stain
Red
process of fast acid stain
carbofuchsin
water
acid alcohol
methylene blue
what uptakes the dye in acid fast stain
mycolic acid
how does mycolic acid impact the cell
affects permeability of cell
TB grows inside what cells
macrophages/monocytes
what are 2 ways TB inhibits job of macrophages
- prevents phagosome/lysosome fusion
2. escape phagosome
what might allow TB to escape phagosome
hemolysin
how does TB prevent acidification of phagosome
produces NH4
what does cell wall components of TB produce and their role
TNF alpha
lung damage
what are 3 ways you could diagnose TB
- examination of sputum
- chest x-ray
- tuberculin skin test (PPD)
