Molecular Methods for Tuberculosis Diagnosis and Drug Resistance Assessment

This article reviews the principles and clinical interpretation of molecular diagnostic tests for tuberculosis, focusing on Xpert MTB/RIF Ultra, line probe assays, whole genome sequencing, and targeted next-generation sequencing. These molecular tools provide rapid and accurate detection of Mycobacterium tuberculosis and its drug resistance profiles. Special attention is given to the discordance between genotypic and phenotypic drug susceptibility testing, including borderline resistance, heteroresistance, and rare genetic mutations. Understanding the strengths and limitations of each method is critical for accurate diagnosis, appropriate treatment selection, and improving patient outcomes.