Current Landscape of Molecular Diagnostic Tests for Tuberculosis and Drug Resistance: From Routine Practice to Emerging Technologies

The rapid and accurate diagnosis of Mycobacterium tuberculosis (MTB) infection, along with timely detection of drug resistance, is crucial for controlling tuberculosis (TB) globally. Over the past two decades, molecular diagnostic assays have transformed TB detection, ranging from centralized high-throughput platforms to portable point-of-care systems. Our review provides a comprehensive overview of key WHO-endorsed and emerging molecular assays for TB diagnosis and drug resistance detection. Cartridge-based systems such as Xpert MTB/RIF, Xpert MTB/RIF Ultra, and Xpert MTB/XDR (Cepheid) have revolutionized TB diagnostics by offering automated, rapid detection with high sensitivity and specificity, especially in resource-limited settings. High-throughput platforms like COBAS MTB and MTB-RIF/INH (Roche) and line probe assays such as GenoType MTBDRplus and MTBDRsl (Hain Lifescience) have proven valuable in centralized laboratories for resistance profiling. Decentralized and portable systems, including Truenat MTB (Molbio Diagnostics), TB-LAMP (Eiken Chemical), and EasyNAT TB (Ustar Biotech), address critical diagnostic gaps in peripheral settings, offering rapid results with simplified workflows. The SS-LAMP assay (MAScIR) and the Deeplex-MycTB targeted sequencing assay (Genoscreen) exemplify regionally developed and advanced molecular approaches, respectively, contributing to improved diagnosis and surveillance efforts. Despite the diversity of these platforms, challenges remain concerning cost, infrastructure, and implementation in high-burden, low-resource environments. This review highlights the strengths, limitations, and roles of each assay within TB diagnostic strategies, emphasizing the need for integrated approaches to achieve global TB control targets.