Multidrug-Resistant Mycobacterium tuberculosis Isolated from China 2

19 20 Abstract: To investigate the molecular characterization of multidrug-resistant 21 tuberculosis (MDR-TB) isolates from China and the association of specific mutations 22 conferring drug resistance with different genotype strains, we performed spoligotyping 23 method and sequenced nine loci of katG, inhA and oxyR-ahpC intergenic region, rpoB, 24 tlyA, eis, rrs, gyrA and gyrB in 128 MDR-TB isolates. Our results showed that 108 25 isolates (84.4%) among these isolates were Beijing family strains, 64 (59.3%) of which 26 were identified as modern Beijing strains. Compared with the phenotypic data, the 27 sensitivity and specificity of DNA sequencing were 89.1% and 100.0% for INH, 93.8% 28 and 100.0% for RIF, 60.0% and 100.0% for CAP, 84.6% and 99.4% for KAN and 90.0% 29 and 100.0% for OFX resistance, respectively. The most prevalent mutations among these