Scientists identify mutations in DNA for early diagnosis of drug-resistant bacteria for TB

Subject : Science and technology

Section: Health

Concept :

According to the World Health Organization, India has the highest burden of Multi-Drug Resistant-TB (MDR-TB).
There are nearly 0.39 million cases across the world.
A group of scientists at CSIR-Centre for Cellular & Molecular Biology (CCMB) has observed that mutations in DNA repair genes can be used for early diagnosis of MDR/XDR-TB.
It was found through the whole genome sequencing of bacteria, that perturbed DNA repair aids in the acquisition of drug resistance in Mycobacterium Tuberculosis.

Tuberculosis (TB)

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis.
TB commonly affects the lungs (pulmonary TB) but can also affect other parts (extrapulmonary TB)
Tuberculosis spreads from person to person through the air, when people who are infected with TB infection cough, sneeze or otherwise transmit respiratory fluids through the air.
The most common risk factor associated with TB is HIV & other conditions that impair the immune system.
Common symptoms of tuberculosis are Chronic cough with blood-tinged sputum, Loss of weight, Loss of appetite, Fever and night sweats, Fatigue , etc.
TB Treatment: consists of four drugs:
- Isoniazid (INH)
- Rifampicin
- Pyrazinamide
- Ethambutol

Multidrug-Resistant TB (MDR-TB)

In MDR-TB, the bacteria that cause TB develop resistance to antimicrobial drugs used to cure the disease.
MDR-TB does not respond to at least isoniazid and rifampicin, the 2 most powerful anti-TB drugs.
Treatment options for MDR-TB are limited and expensive. CBNAAT (Cartridges Based Nucleic Acid Amplification Test) is used for early diagnosis of MDR-TB.

Extensively Drug-Resistant TB (XDR-TB)

XDR-TB is a form of multidrug-resistant TB with additional resistance to more anti-TB drugs.
People who are resistant to isoniazid and rifampicin, plus any fluoroquinolone and at least one of three injectable second-line drugs (amikacin, kanamycin, capreomycin) are said to have XDR-TB.
To achieve goal: To end TB by 2025