FIG. 1.

Effect of auxotrophy on the intracellular multiplication of M. tuberculosis. Murine macrophages were infected at a multiplicity of infection of 1:1 with either H37Rv (●) or mutant strain metB (○), proC (▾), or trpD (▿). The numbers of bacteria were quantified and were expressed as means and standard errors for each strain per time point. All standard errors were less than 0.2%. Results are representative of three independent experiments.