Heterogeneity in transmission dynamics among lineage 2 Mycobacterium tuberculosis strains in Kobe, Japan revealed by population-based whole-genome sequencing analysis

Tuberculosis (TB), caused by the bacterium Mycobacterium tuberculosis (Mtb), continues to remain a major health concern worldwide. Japan is among the largest elderly countries, and it is evident that elderly patients with TB could significantly contribute to shaping Japan's current Mtb population dynamics. Furthermore, the L2 lineage of Mtb is characteristically predominant in Japan. However, there is no clarity yet on how these two elements contribute to the transmission dynamics of Mtb in Japan. To address this, we conducted a population-based whole-genome sequencing analysis of 550 Mtb strains obtained from patients with TB reported between 2016 and 2018 in Kobe, Japan.