Figure 4.

N-acetylcysteine (NAC) prevents metal-induced persister formation. Tetracycline-induced rates of persister cells (“Tet” black bar) are not affected by the addition of NAC during the pretreatment (“NAC + Tet”, black bar). Copper and zinc-induced rates of persistence (respectively “Cu”, dark gray bar; and “Zn” light gray bar) are affected by concomitant addition of the antioxidant NAC (“Cu + NAC”, dark gray bar; and “Zn + NAC” light gray bar). Results are shown as the mean of biological replicates and the symbols ** (p < 0.01) and *** (p < 0.001) indicate significant differences using Student’s t-test. NS indicates the absence of significative difference.