Elucidating the effects of the macrophage environment on the efficacy of anti-mycobacterial drugs. Mycobacterium tuberculosis CDC1551

We examined the transcriptional responses of intracellular M. tuberculosis exposed to different front-line drugs during macrophage infection. Our data reveal that Mtb experiences amplification of multiple host-derived pressures following drug exposure. The stresses from the host environment have a dominant impact on Mtb gene expression to the extent that the transcriptional profiles cluster according to environment, ie. broth vs host cell, rather than drug. Overall design: Transcriptional responses of M. tuberculosis to front-line drugs were studied under two environmental conditions: J774 macrophages vs. 7H9 broth, and 4 drugs were examined: INH, RIF, EMB, and PZA.