UC San Diego

The co-emergence of multidrug resistant strains and the HIV pandemic has made tuberculosis the leading public health threat. The causative agent is Mycobacterium tuberculosis (Mtu), a facultative intracellular parasite. Mycobacterium leprae (Mle), a related organism that causes leprosy, is an obligate intracellular parasite. As transporters are essential for bacterial growth and persistence, we conducted comparative analyses of transport proteins encoded within the genomes of these organisms. A minimal set of genes required for intracellular life and extracellular life, and genes that may have been horizontally transferred were identified. Drug efflux systems utilizing primary active transport mechanisms have been preferentially retained in Mle and still others preferentially lost. Transporters involved in adaptation were found in Mtu were mostly lost in Mle. These findings may provide starting points for experimental studies that may elucidate the pathogenesis of these two pathogenic mycobateria