FIG 5.

Antibiotic tolerance increases as ACFS biofilms mature. (A) Relative CFU (CFU at each time point divided by the CFU value before treatment, i.e., t = 0) from biofilms and planktonic cells from the same wells, grown for 3, 6, and 11 days in ACFS. Cultures were treated with clarithromycin (20 μg/ml) and imipenem (15 μg/ml) for 48 h, and CFU were measured at 0, 24, and 48 h. (B) Survival from 48-h CFU time points (triplicate wells). P values between biofilm and planktonic cells are 0.01099, 0.0006, and 0.1815 for 3, 6, and 11 days, respectively. P value for biofilms between 3 and 11 days is 0.09046. P values were calculated using the Student’s t test.