MICR3001 Lecture Notes - Lecture 10: Mycolic Acid, Mycobacterium Tuberculosis, Alveolar Macrophage
Document Summary
1/3 of the world"s population has been infected with tb bacterium. 9 000 000 new cases per year: 25 000 new cases per day. 1. 5 000 000 deaths per year: 4 000 deaths per day. Majority of those infected will not get tb disease. Identification in ancient specimens: egypt (6 000 yr), se asia, n & s america (2 000 yr, 1500-500bc pleural adhesions (confirmed by adna, bone is a good indicator of adna. Alveolar macrophages are supposed to be a checkpoint: tb lives inside them. Unique cell wall: mycolic acid, long-chain fatty acid, almost impenetrable membrane. Includes: lipid bilayer, peptidoglycan, porins, mycolate, acyl lipids, arabinogalactan, lam (necessary and important for survival) Can survive in walled-off lesions (granulomas) for decades. Bacterial replication and cellular infiltration: macrophages leave circulation and recruit to site on infection, bacteria multiple within accumulation of macrophages.
