Mycolic wall
The lipid-rich envelope is a fortress and a reason growth is slow.
Bacilli that reach alveoli may be eaten by macrophages and still survive inside them — a slow intracellular story.
Infectiousness is mainly from people with active pulmonary disease who cough. Latent infection is not a cough factory.
Parts
Macrophage niche
The bacillus can live inside the very cell sent to kill it.
Cavity
In some lungs, holes become factories of airborne nuclei.
Lymph travel
Bacilli can leave the lung and seed other organs.
Slow generation
Division measured in hours to days, not minutes like E. coli in broth.
Persisters
Sheltered cells help explain why programmes talk in months, not days.
Life cycle
1Inhale nuclei
Shared indoor air delivers a small infectious dose to a new host.
2Contain or progress
Most infections are contained. Some become primary disease, especially in children.
3Latency years
Bacilli may sit quietly while the person feels well.
4Active cough
If disease wakes in the lung, months of care and infection-control follow — clinically directed.
No culture or drug-recipe steps are given.
Keep exploring
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