[1] Members of the MTC can be distinguished from all other bacteria by the presence of 63 conserved signature indels (CSIs) present in diverse proteins that are exclusively shared by these pathogens.
[4] Due to their exclusivity for the MTC complex and presence in highly conserved regions of proteins, these CSIs provide novel means for functional and diagnostic studies (including potential targets for development of novel therapeutics).
The IJSEM article reports that M. africanum, M. bovis, M. caprae, M. pinnipedii are 99.21–99.92% identical to M. tuberculosis on the whole-genome level, failing the criteria to be considered independent species.
Authors of the article note that these names do refer to stable lineages with meaningful clinical distinctions, recommending that them become variants: M. bovis would become M. tuberculosis var.
Transcriptional adaptation can allow M. tuberculosis isolates to optimize their infectivity and transmission in subtly different environments provided by different human host populations.