Mycobacterial diseases

Question 1

Tuberculosis

Answer 1

Slow growing - doubles over 24hrs Aerobes Acid-fast (red rods) staining Lipid rich w/ thick wall

Question 2

TB transmission

Answer 2

Aerosol - microdroplet can stay in the air for an hour Can reach alveoli - replicate in macrophages there & carried to lymph nodes/other organs One cough makes 500 droplets

Question 3

TB enzymes

Answer 3

PIM - encourages endosome fusion to phagosome = nutrients ManLAM & SapM - prevent lysosome fusion

Question 4

Pott and Scofula

Answer 4

Potts = tB of the spine Scofula = lymphadenopathy infection

Question 5

TB DX

Answer 5

CXR - upper lobes w/ cavitary lesions Cough, hemoptysis, systemic Gene Xpert - tells you if TB and if rifampin resistant

Question 6

TB skin testing

Answer 6

>5mm - HIV, Contact, abnormal CXR, immunosuppressed >10 - recent immigrants, IV drug users, high-risk medical condition, medical employee >15mm if no risks

Question 7

TB antigens

Answer 7

ESAT & CFP positive - to rule out false positive from skin test. Not seen in other mycobacterium or react with the BCG vaccine GFT -IT & T-SPOT.TB

Question 8

Buruli Ulcer

Answer 8

M. ulcerans Optimal growth at 32*C From contaminated water Mycolactone toxin = necrotic painless cell death Tx = surgery & rifampin + streptomycin/amikacin Equatorial regions

Question 9

Mycobacterium leprae

Answer 9

Leprosy Oldest recorded disease Very slow growing (doubles every 20 days) Affects peripheral nerves, skin, mucosa Infects monocytes Armadillos and humans Transmitted through nasal secretions Tx = rifampin, dapsone, clofazimine for 12 months

Question 10

Nontuberculous Mycobacteria

Answer 10

Often resistant to antibiotics In soil and water No human to human transmission Increasing prevalence Lung most common - nodular bronchiectasis & fibrocavitary

Question 11

NTM Growth, Transmission, & Patterns of Disease

M. avium

M. intercelluarae

M. kansasii

M. abscessus

M. marinum

M. ulcerans

Answer 11