Second-line Drug Resistance Characterization in <i>Mycobacterium tuberculosis</i> by Genotype MTBDRsl Assay

Drug-resistant tuberculosis (TB) remains a main hurdle for national tuberculosis control programs. As per the estimates of World Health Organization (WHO), in 2016, the multidrugresistant (MDR) TB/rifampicin-resistant (RR) TB was 19% in previously treated patients and 4.1% in newly diagnosed TB patients The diagnosis of drug resistance for first-line antitubercular drugs is easy due to availability of WHO-endorsed molecular tests like Xpert MTB/RIF and line probe assays (LPAs). The second-line drug resistance detection is a challenge due to very limited WHOendorsed tests The most reliable test for second-line drug resistance is phenotypic drug-susceptibility testing (DST) in liquid culture, which is laborious and time consuming.