Molecular diagnosis, detection and treatment of drug resistant mycobacterium tuberculosis

Abstract EN

Tuberculosis has affected humans for centuries and the number of mycobacterium tuberculosis infections have been shown to be increasing worldwide, mainly due the increased number of patients with HIV infection and AIDS disease worldwide, an increasing number of elderly patients and the emergence of multidrug resistant tuberculosis.

The disease is caused by a bacterium called Mycobacterium tuberculosis (MT) and is also called tubercle bacilli (TB).

Inhalation is the predominant pathway of MT infection, making pulmonary tuberculosis the most common form of tuberculosis.

Tuberculosis may arise either from a recent infection with MT, or from the reactivation of dormant bacilli, years or decades after initial infection.

Extra pulmonary tuberculosis mainly results from reactivation of a tuberculosis focus after hematogenous dissemination or lymphogenous spread from a primary, usually pulmonary focus.

Tuberculosis may demonstrate a variety of radiological features depending on the organ site involved and may mimick other pathologies.

The final diagnosis of tubercles disease mainly depends on the detection of the causative organism on histopathological examination, culture and molecular diagnostic assay for mycobacterial DNA on material obtained during bronchoscopy washings, fine needle aspiration cytology (FNAC) or biopsy.

Tubercle bacilli can be multidrug resistant-TB (MDR-TB), if the tubercle bacilli are resistant to at least isoniazid and rifampin (first-line drugs) or extremely drug resistant-TB (XDR-TB), if the tubercle bacilli are resistant to isoniazid and rifampin, plus resistant to any fluroquinolone and at least one of the three injectable second-line drugs such as amikacin, kanamycin, or capreomycin