Mycoplasma/Mycobacteria/Leprosy

Question 1

Mycobacteria organisms

Answer 1

acid fast due to waxes in their cell walls

slow growing, mostly facultative intracellular invaders

Question 2

mycobacteria virulence factors

Answer 2

facultative intracellular pathogen; glycolipids promote resistance to intracellular killin, inhibit interferon-activation of macrophages, prevent phagolysosomal membrane fusion, and stimulate destructive cell-mediated inflammatory injury

Question 3

histologic characteristics tuberculosis

Answer 3

caseating granulomas

Question 4

ghon complex

Answer 4

primary lung lesion with caseating granulomas in draining lymph nodes

Question 5

characteristic symptoms with secondary TB infections

Answer 5

fever, night sweats, weakness, loss of appetite, weight loss, productive cough, blood-streaked sputum

Question 6

granuloma formation

Answer 6

development of TH1 cells results in secretion of interferon g
interferon-g results in aggregation of epithelioid macrophages
inability of macrophage to kill bacteria

Question 7

Leprosy (mycobacterium leprae) general features

Answer 7

obligate intracellular mycobacterium
transmitted by respiratory aerosols
slow growing
limited to cooler parts of the body

Question 8

pathogenesis of leprosy

Answer 8

begins in respiratory tract, disseminates through bloodstream to skin
infects schwann cells and perineural tissues

Question 9

key features of leprosy

Answer 9

anesthesia of skin

Question 10

forms of leprosy

Answer 10

1. tuberculoid leprosy: granulomas

2. lepromatous form: foam cells; extensive deformities of skin, contagious