Original Article
Yuanyuan Zhang, Zhaofen Wang,
Abstract
Objectives: To evaluate the diagnostic value of high-resolution melting curve (HRM) analysis to isoniazid-resistant Mycobacterium tuberculosis (MTB) derived from patients on the Qinghai-Tibet Plateau, compared with DNA sequencing. Methods: A total of 96 clinical isoniazid (INH) resistant isolates, determined by drugs susceptibility testing using the proportion method on Lowenstein-Jensen (L-J) medium, were included into analysis. Codon KatG315 of these isolates was analysed by both HRM and DNA sequencing, and results were compared. Results: Of the 96 INH resistant strains, 55 isolates with katG315 mutations were detected by HRM, accounting for 57.3%, and 50 strains (52.1%) were found by sequencing, which is considered as gold standard for DNA mutations. The sensitivity of HRM is 88.0%, the specificity is 76.1%, Mc-Nemar test P=0.332 and kappa coefficient is 0.644. Conclusion: HRM and sequencing have moderate consistency in detecting KatG315 mutations. Furthermore, HRM can detect heterogeneous resistance. It would be a superior method for the detection of INH resistance-related mutations at basic level units of Qinghai province.