Fig 5. Low pH increases the potency of Q203.

A) IC50 curves of H37Rv treated with Q203 at pH 7.0, pH 6.5 and pH 5.5 for 6 days in agitated culture. IC50 values for Q203 (nM) at each pH shown in the table. OD600 values are represented as relative to the no drug conditions because H37Rv growth is attenuated at pH 5.5. B) Day 0, 3, 6 CFU of H37Rv grown in agitated culture over 6 days at pH 7.0, 6.2, and pH 5.7 in the presence of 30x MIC Q203 (90 nM) or vehicle control (DMSO). Day 0 CFU timepoint is shared across all groups from DMSO pH 7 condition. Analysis was performed using a one-way ANOVA with Tukey post-test. ** p-value < 0.01, **** p-value <0.0001. Data depict single experiments that are representative of at least 3 independent studies.