MTBC

MTBC stands for the Mycobacterium tuberculosis complex, a group of closely related mycobacteria that cause tuberculosis in humans and many animals. The complex includes species such as Mycobacterium tuberculosis, M. bovis, M. africanum, M. canettii, M. caprae and M. microti, among others. Members share high genetic similarity and have a common ancestor dating back tens of thousands of years. They are slow-growing, lipid-rich bacteria with a mycolic-acid–containing cell wall and appear as acid-fast bacilli on staining.

MTBC organisms are primarily transmitted through airborne droplets from people with active pulmonary tuberculosis. Infection can be latent, with no symptoms, or progress to active TB, typically affecting the lungs but potentially involving other organs. Symptoms include chronic cough, fever, night sweats, and weight loss. Diagnosis combines clinical assessment with microbiology and molecular tests: sputum smear microscopy for acid-fast bacilli, culture on specialized media (e.g., Lowenstein-Jensen or Middlebrook), nucleic acid amplification tests (such as Xpert MTB/RIF), and interferon-gamma release assays to detect prior exposure.

Treatment relies on long-term combination chemotherapy. First-line therapy usually includes isoniazid, rifampicin, pyrazinamide, and ethambutol for a minimum of six months; drug susceptibility testing guides regimen. Resistance to isoniazid and/or rifampicin defines multidrug-resistant TB, requiring second-line drugs and longer regimens. BCG vaccination uses a live M. bovis strain and provides variable protection, mainly against severe forms in children.

Public health measures focus on early case detection, prompt treatment, infection control, vaccination, and monitoring of drug resistance to reduce transmission and TB burden worldwide.