Eukaryotic genes in Mycobacterium tuberculosis could have a role in pathogenesis and immunomodulation.

Acquisition of new genetic material through horizontal gene transfer has been an important feature in the evolution of many pathogenic bacteria. Here, we report the presence of 19 genes of eukaryotic origin in the genome of Mycobacterium tuberculosis, some of which are unique to the M. tuberculosis complex. These genes, having been retained in the genome through selective advantage, most probably have key functions in the organism and in mammalian tuberculosis. We explore the role these genes might have in manipulation of the host immune system by altering the balance of steroid hormones.