The goal of this project is to assess the efficacy of combinatorial drug treatment, involving different host-active compounds together with anti-TB drugs against intracellular Mtb, using a panel of six drug resistant clinical strains. This strain panel will be selected to be representative of the differing degrees of drug-resistant complexities up to multidrug resistance (MDR). The desirable outcome would be the identification of combinations of host active compounds and TB drugs that increase the efficacy of drug action against the resistant strains.