FIGURE 6.

Comparison of PZA/POA accumulation in Rv1258c mutants of M. tuberculosis. [¹⁴C]PZA was added to 5 × 10⁹ M. tuberculosis H37Ra and the Rv1258c mutant strains at 1 mCi/ml at pH 6.6. At different times after PZA addition, portions of bacterial cells were removed and washed by filtration using PBS (pH 6.6) as described in Methods. The results of PZA/POA accumulation are shown by autoradiography (A) and scintillation counting (B). The S292L mutant accumulated less PZA/POA than the V219A mutant, while both mutants accumulated less drug than the parent strain M. tuberculosis H37Ra as shown in both (A,B).