Recently, the World Health Organization (WHO) has released a revised definition of extensively drug-resistant (XDR) tuberculosis (TB) that should be used for clinical and surveillance purposes starting from 1 January, 2021 [1, 2]. The previous XDR-TB was TB is resistant to any fluoroquinolone (levofloxacin and/or moxifloxacin) at least one three second-line injectable drugs (SLIs: capreomycin, ...