Title: Novel diagnostic approaches towards RR-TB detection: Advancing the fight against MDR-TB control
Abstract:
Tuberculosis (TB) ranks as one of the most widespread infectious diseases in the world due to the fact that multidrug resistant (MDR), extensively resistant (XDR), and totally resistant (TDR) strains are becoming more prevalent. Therefore, in order to curb this widespread, there is an ardent need for the rapid, accessible, and affordable diagnostic systems or approaches towards drug-resistant TB. In this study, we introduce two specialized nucleic acid probes, targeting the most prevalent point mutations associated with the rifampicin-resistant TB (RRTB), an easy analyte generation protocol involving loop-mediated amplification (LAMP), and simple molecular diagnostic approaches for the rapid detection of RR-TB, a critical surrogate for MDR-TB. These probes are rationally designed, and are Locked Nucleic Acid (LNA)- enhanced for specifically targeting the conserved Mycobacterium tuberculosis sequences associated with RR-TB. One of the diagnostic approaches introduced in the study is based on fluorescence anisotropy and the other one is based on a biosensing platform as a proof-ofconcept. Through systematic optimization of hybridization conditions, probe design, LAMP protocol, electrochemical parameters, and modification of gold screen printed electrodes (AuSPE), these approaches deliver outstanding accuracy, specificity, sensitivity, and robustness. Testing of clinical samples show the results to be in strong concordance with the gold standard DST and Xpert MTB/RIF, with the lower turnaround time and cost. This dual probe system is modular, and scalable, providing a prospect of translating into a portable point-of-care format as these diagnostic approaches pave a way toward democratizing MDR-TB diagnostics, and reinforces the path toward rapid, and inclusive TB eradication strategies.
Keywords: TB, MDR-TB, RR-TB, LAMP, LNA, Au-SPE.
