Figure 4.

Δstf0 is more resistant to LL-37 compared to WT Mtb. The indicated strains of Mtb were exposed to increasing concentrations (0, 6.5, and 65 μg/mL) of LL-37. After 3 days, Mtb viability was measured by plating bacteria on solid agar to enumerate cfu counts. Data are representative of one of three independent experiments each performed in triplicate. * P = 0.74 (not significant) for the comparison of Δstf0 versus WT; ** P = 0.012 for the comparison of Δstf0 versus WT. Error bars correspond to the means (±SD); an error of less than ∼2% is not visible on this graph (SD of Δstf0 at 65 μg/mL = 1.0%; SD of Δstf0 + pstf0 at 65 μg/mL = 1.27%).