TB

Question 0

Mycobacterium avium

Mycobacterium intracellulare

Answer 0

-Gr+ bacilli
-form branches, filamentous
Virulence
-waxy lipid coat!
-clumping=cord factor
Diagnostic
-Ziehl-Neelsen Acid-fast stain
-Fluorescent dye
-*auramine O
-slow growth rate

Question 1

Mycobacterium tuberculosis

Answer 1

-Gr+ rods
-acid fast
-aerobic
-Ghon complex=host immune response often controls TB–> results in pulm granuloma + calcified fibrotic hilar/mediastinal lymph nodes
-Miliary TB: tubercle enlarges–>caseating necrosis
Virulence
-survives/replicates in UNactivated MACs
-waxy lipid coat
-clumping=cord factor
-cell wall=mycolic acid, lipoarabinomannan scavenge ROIs
-elicits granulomas–>giant cells
-only indiv w/ TB of lungs or larynx are infx (pulmTB)
-latent is noninfectious
Diagnostic
-lowenstein-Jensen
-Xpert MTB/RIF
-tuberculin skin test (TST)
-liquid tuberculin (PPD)
-IFN-gamma release assays (IGRAs)
-*BCG vaccine