Figure 7.

Schematic representation of Tdmh_Mtb dependent self-balanced growth of intracellular Mtb in immunocompetent host. The status of nutrient availability, stress effect and net growth of Mtb in Mφ at initial (t=0) and later (t>0) phases of infection are represented by green arrow, red arrow and open circle, respectively. Two possible scenarios under which this balance could be perturbed are depicted. Scenario 1 shows the effect of Tdmh_Mtb inactivation on bacterial burden in immunocompetent host. Although the nutrient influx in a Δtdmh_Mtb mutant is likely retarded, this deficiency is outweighed by increased tolerance of the mutant to the host-induced stresses. In scenario 2, reduced intracellular stress in an immunocompromised host can mitigate the effect of Tdmh_Mtb on stress sensitivity, such that Tdmh-dependent nutrient assimilation can accelerate growth of wild-type Mtb in such host.