The evolution of drug resistant Mycobacterium tuberculosis

Sinopse

Mycobacterium tuberculosis (Mtb) poses a global health catastrophe that has been compounded by the emergence of highly drug resistant Mtb strains. We used whole genome sequencing (WGS) to directly compare the accumulation of mutations in Mtb isolated from cynomolgus macaques with active, latent and early reactivation disease. Based on the distribution of single nucleotide polymorphisms (SNPs) observed, we calculated the mutation rates for these disease states. Our data suggest that during latency, Mtb acquires a similar number of chromosomal mutations as would be expected to emerge in a logarithmically growing culture over the same period of time despite reduced bacterial replication during latent infection. The pattern of polymorphisms suggests that the mutational burden in vivo is due to oxidative DNA damage.