• M. tuberculosis is an acid fast organism.
• It has no Gram reaction (neither + or - ).
• The organism has a wax-like coat around it.
• The coat seems to protect the bug from the normal means of bacterial killing our body uses.
• Also, it's this waxy coat that causes the immune system to go wild.
• We develop a Type IV (cell mediated) hypersensitivity, which results in tissue destruction.

• Typically, the primary infection occurs in the lung, and results in an area of granulomatous inflammation. This initial lesion is known as a 'Ghon focus.'
• The spread of the infection may be contained at this point. Locked in the granuloma.
• Granuloma formation is complex, involving the bug, macrophages and lymphocytes.
• The result is Type IV or delayed hypersensitvity.
• In many cases, however, this primary focus may reactivate (even years later),
• producing what is called secondary or endogenous tuberculosis.
• During this secondary phase, the bug may spread widely throughout the body.
• As we saw in the case of Anuhuak, her spine and kidneys.

All we really had were two lumbar vertebrae, how do we know is was TB?                 Back