Figure 3. Salicylate-induced persistence requires oxygen.

(A) Survival with and without 5 mM salicylate after 6 hours of 5 μg/ml ciprofloxacin treatment under anaerobic conditions with and without 40 mM fumarate, an alternative electron acceptor. Error bars show standard errors from n = 3 biological replicates. (B) Survival after 6 and 24 hours of 5 μg/ml ciprofloxacin treatment with and without 120 μM H₂O₂ as a positive control for oxidative stress. Error bars show standard errors from n = 3 biological replicates. We used the Student’s t-test to test for statistical significance. (C) Proposed mechanism for salicylate-induced persistence.