AFB Drug Susceptibility Panel - (14 drugs), Pure Culture

Tuberculosis is a chronic respiratory tract infection causing fever, cough and weight loss. It is commonly caused by Mycobacterium tuberculosis (M.tb). Many diagnostic techniques are available for diagnosis of tuberculosis which include staining, culture and nucleic acid detection. any diagnostic techniques are available for diagnosis of tuberculosis which include staining, culture and nucleic acid detection. Among nucleic acid detection techniques are polymerase chain reaction (PCR), Cartridge based nucleic acid amplification technique (CBNAAT), Line probe assay (LPA), Next generation sequencing (NGS).

Test Overview

This test is done when drug resistance is suspected in a case of tuberculosis (for e.g., contact with a drug-resistant/ failed treatment case, failure of 1st line treatment, previous history of use of 2nd line treatment drugs), or the resistance has been detected by nucleic acid-based tests.

The results of MGIT susceptibility testing are the gold standard and take up to 4 weeks. However, WHO still recommends it to confirm findings through LPA & NGS This test detects the resistance of pure culture of M. tb towards the first line of drugs i.e., Isoniazid, Rifampicin, Ethambutol, and pyrazinamide Fresh patient sample is not required (except when requested).

The results of the testing will be given for each antibiotic separately. Based on the resistance detected by the doctor will prescribe the anti-tubercular treatment.

14 antitubercular drugs can be tested for sensitivity in this test. These are -

1. Isoniazid.
2. Rifampicin.
3. Ethambutol.
4. Pyrazinamide.
5. Streptomycin.
6. Kanamycin.
7. Moxifloxacin.
8. Amikacin.
9. Ethionamide.
10. Clofazimine.
11. Capreomycin.
12. Bedaquiline.
13. Linezolid.
14. Levofloxacin.

After a Mycobacterium growth indicatory tube (MGIT) reports a positive M.tb culture result, this test has to be scheduled.

Who should do the AFB Drug SUSCEPTIBILITY Panel14 Drugs test?

Latent tuberculosis has no symptoms. If you have it, an epidermis or blood work can detect it.

Active TB illness symptoms include:

• Coughing for longer than three weeks.
• Chest pain.
• Coughing up blood.
• Perpetual fatigue.
• Sweats at night.
• Chills.
• Fever.
• Reduced appetite.
• Loss of weight.

Visit your doctor to get tested if you experience any of these signs. If you experience chest pain, get immediate medical attention.

Written by: Dr Vishal Wadhwa, M.D, D.N.B Microbiology, Medical Affairs