Molecular Diagnostic Methods for Multidrug Resistance in Tuberculosis: A Review

Tuberculosis (TB) has existed for millennia and remains a major global health problem. Novel technologies for rapid detection of anti-TB drug resistance have therefore become significant in TB research and development MDR- TB and XDR – TB is a persistent threat to the public health. Various molecular tests have been developed to detect mutations associated with resistance. The advantages of molecular methods of DST include rapid turnaround time, but the disadvantages include a low sensitivity for some compounds, however a major concern is cost. This leads to the need of rapid and robust diagnostic techniques to detect the drug resistance in TB. Though culture-based methods currently remain the reference standard for drug susceptibility testing, molecular diagnostic methods helps in prompt detection of the drug resistance, quicker diagnosis, surmounting the programmatic management and surveillance of drug-resistant TB, potential for high through put, and also have fewer requirements for ensuring laboratory biosafety. Line probe assay and Gene Xpert MTB/RIF assay are the most widely used methods and furthermore these techniques are endorsed by world health organization (WHO). Newer advances in these two technologies as SL-LPA and Ultra assay respectively also have promising future in the diagnostic field.