Determining RPO Gene mutation responsible for rifampicin resistance in pulmonary tuberculosis assessed by line probe assay

• Author Details:   
• Nidhi Singh ^*
• Ved Prakash Sharma
• Amit Kumar Singh
• Rajesh Agarwal
• Rajesh Shah

---

Introduction: Mycobacterium tuberculosis causes TB illness, which is increasingly widespread. The Geno Type MTBD Rplus assay or line probe assay (LPA) detects the most prevalent genetic changes generating rifampicin (RIF) resistance at (rpoB gene mutations) codons 516, 526, and 531, as well as Mycobacterium tuberculosis.
Materials and Methods: The study was conducted between February 2023 and October 2023. The sample was obtained from RMCH and processed at the Intermediate Reference Laboratory (IRL) at KGMU Lucknow, Uttar Pradesh, India. A total of 98 acid-fast bacilli (AFB) smear-positive sputum samples were processed by LPA.
Result:  This Geno Type MTBDR plus assay was employed for analyzing 98 acid-fast bacilli smear-positive sputum samples, and of these, 25 samples had no Mycobacterium tuberculosis detected, 8 samples were RIF resistant, 2 indeterminate samples were found, and 63 samples were found to be susceptible to RIF. The assay indicated corresponding resistance rates of 10.95 % (8/73). The most frequently identified genetic mutation responsible for RIF's resistance was the 531 codon of the rpoB gene, and that was found in 10.95 % (08/73) of rifampicin-resistant strains.
Conclusion: In conclusion, the Bareilly region had a higher prevalence rate of rifampicin resistance, reaching 10.95%. This study underscores the use of LPA with its short turnaround time and excellent specificity and sensitivity for detecting MDR TB.

Keywords: Rifampicin resistance, Line probe assay, Mycobacterium tuberculosis, Pulmonary tuberculosis, rpo gene mutation.