There is no correlation between sublineages and drug resistance of Mycobacterium tuberculosis Beijing/W lineage clinical isolates in Xinjiang, China

The Beijing/W lineage strains are the major prevalent strains in China. The prevalence, mortality and drug-resistant rates of tuberculosis in Xinjiang, Northwestern China are higher than in other parts of the country. Our previous study results showed that the dominant strains of Mycobacterium tuberculosis (MTB) were ‘Beijing/W lineage’ MTB in Xinjiang; those strains had no significant correlation with drug resistance. We investigated whether the prevalence of ‘Beijing/W lineage’ sublineage strains was associated with drug resistance. We collected 478 sputum specimens from patients with pulmonary tuberculosis. Beijing/W strains and their sublineages were identified by distinguishing five specific large sequence polymorphisms, using polymerase chain reaction. All strains were subjected to a drug susceptibility test using the proportion method on Löwenstein–Jensen culture medium. In total, 379 clinical isolates of MTB were isolated and identified, 57·26% of these isolates were identified as Beijing/W strains, of which 11·06% isolates were in sublineage 105, 14·74% isolates in sublineage 207, 69·59% isolates in sublineage 181, and 4·61% isolates in sublineage 150. None of the isolates was in sublineage 142. Our data showed there were four sublineages of Beijing/W isolates in Xinjiang province, China. However, there were no correlations between drug resistance and the sublineages of Beijing/W strains.