Local adaptation of Mycobacterium tuberculosis on the Tibetan Plateau

Significance The global distribution of different Mtb lineages is very structured, with a few lineages that are globally widespread, whereas many others are restricted to particular geographic regions. Although local adaptation has been a favored model for explaining the sympatric relationship between the bacteria and host in these geographic regions, this has been difficult to study. Human migration has led to intermixing of ethnicities and has disturbed the bacterial population structure, thereby masking the putative genetic determinants that may have evolved from selection pressures in a given region. Here, by analyzing the genomes of hundreds of Mtb strains sampled from the relatively isolated population of Tibetan, we provide genetic evidence that Mtb can evolve to adapt to local populations and environments.