Volume 11,Issue 2
Clinical Evaluation of Targeted Next-Generation Sequencing for Detecting Rifampicin and Isoniazid Resistance in Mycobacterium tuberculosis
Objective: To evaluate the clinical efficacy of targeted next-generation sequencing (NGS) technology in detecting rifampicin and isoniazid resistance in Mycobacterium tuberculosis (MTB). Methods: Patient specimens from 31 cases of MTB culture-positive and phenotypically drug-resistant (Drug susceptibility test, DST) collected between May 2024 and November 2025 were analyzed. Targeted NGS was used to detect mutations in resistance genes such as rpoB, katG, and inhA. Using DST as the gold standard, the sensitivity of NGS in detecting rifampicin and isoniazid resistance and its mutation spectrum were analyzed and compared with the PCR melting curve method, with a focus on evaluating NGS's ability to re-detect samples missed by PCR. Results: Among 15 rifampicin-resistant samples, NGS detected 13 cases with rifampicin resistance mutations, while 2 cases had no clear rifampicin resistance mutations identified, yielding a sensitivity of 86.67% for detecting resistance, significantly higher than that of the PCR melting curve method. For 17 isoniazid-resistant samples, NGS detected all isoniazid resistance mutations, achieving a sensitivity of 100%, which is also significantly higher than that of PCR. Among the 31 missed resistance mutations by PCR (14 for rifampicin and 17 for isoniazid, with 2 cases missed for both drugs), NGS successfully detected 30, with an overall re-detection sensitivity of 96.77%. NGS also identified various rare mutations and detected multiple heterogeneous resistance samples with mutation frequencies ranging from 0.19 to 0.67, all of which were missed by PCR. Conclusion: NGS demonstrates outstanding re-detection capability for rifampicin and isoniazid resistance samples missed by PCR melting curve method and provides comprehensive resistance spectrum information for multiple drugs in a single test. It offers unique advantages in detecting rare mutations and identifying heterogeneous resistance. For cases with negative PCR results but high clinical suspicion of drug resistance, NGS can serve as an important supplementary verification tool, providing crucial evidence for the precise diagnosis and treatment of complex multidrug-resistant tuberculosis.
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