What Is Microbiology - Tuberculosis

​Tuberculosis 

Tuberculosis is caused by mycobacterium tuberculosis which is an acid fast rod. 

The direct examination of the sputum may reveal the present of acid fast bacilli. The reactivity to the purified protein derivative or PPD skin test is also considered. to identify the cell mediated immune response to the cell wall protein component. 

Mycobacterium tuberculosis is a slow growing bacteria with mycolic acid in the cell wall.

Mycobacterium tuberculosis may replicate in the macrophages which resulted in the formation of tubercle ( granuloma) with caseous necrotic center. 

Granuloma may present in other organs due to erosion of the tubercule which spread to other organs via bloodstream. 

The caseous necrotic centers may undergo liquefaction and cavitation which progress into active disease. The reactivation of mycobacterium tuberculosis occur due to survival of the organism in the tubercles mostly in immunosuppression patient. 

The common mode of transmission may include respiratory droplets. Patient may present with active pulmonary disease such as hemoptysis, fever, cough, loss of weight and sweat at night. 

Mycobacterium tuberculosis may be associated with chronic meningitis. 

The treatment may include isoniazid, ethambutol, rifampin and pyrazinamide. The treatment is based on the susceptibility testing. Culture with special media is considered while testing for drug resistance. 

Vaccination with live mycobacterium form related species such as bacillus Calmette Guerin or BCG or chemoprophylaxis is considered.