A Study on Molecular Detection of Mutations Associated with Second Line Anti-tuberculosis Drug Resistance

Background: Efficient tuberculosis (TB) control is based on an early diagnosis followed by the rapid identification of drug resistance, in order to treat patients adequately, break the chain of transmission, and avoid the spread of resistant strains. Multidrug-resistant (MDR) Mycobacterium tuberculosis have emerged worldwide and seriously threaten TB control and prevention programs. At the same time, the emergence of extensively drug-resistant tuberculosis (XDR TB) has also become an important global health problem.

Objectives: To detect common gene mutation pattern associated with drug resistance against second line anti-tuberculosis drugs in TB patients by SL-LPA as a rapid and early diagnostic test.

Materials and Methods:total 652 sputum samples were received from 30 districts at culture district laboratory, Jamnagar from October 2018 to December 2018, and were included in the study. Second line Second line- line probe assay (SL-LPA) was used to detect mutations associated with resistance for anti-tuberculosis drugs.

Results: Out of the 652 samples analyzed for mutations associated with second line anti-tuberculosisdrug resistance, 43% of the samples exhibited various forms of mutations. Out of these samples, mutations associated with gyrA gene were detected in 36.6% samples, gyrB gene mutation in 0.7% samples, rrs gene mutation in 4.4% samples and eis gene mutation in 1.2% samples.

Conclusion: The present study provide information on the mutation pattern of drug resistant strains present in the geographical area and help to provide the basis for effective strategies for control of drug resistant TB in this region. It also re-emphasizes the importance of second line LPA which can diagnose TB and drug resistance in a single day and allows earlier administration of appropriate treatment as compared to culture result which take 1-2 months.