Figure 3. BF8 and 3-oxo-C12-HSL reverted antibiotic tolerance of isolated PAO1 persister cells.
The total number of viable cells and the number of cells that remained as persisters of untreated controls in each graph were normalized as 100% for the convenience of data comparison across the three experiments. (A) BF8 reverted Cip tolerance of isolated PAO1 persister cells. The harvested PAO1 persister cells were treated with different concentrations of BF8 for 2 h in 0.85% NaCl solution and the viability of PAO1 was evaluated by counting CFU. A portion of each sample was then treated with 200 µg/mL Cip to count the number of PAO1 cells that remained as persisters. The start number of persisters was 2.1×106±3.1×105/mL. (B) Antibiotic susceptibility of PAO1 persister cells treated with and without 5 µg/mL BF8. Persisters were isolated and treated with or without 5 µg/mL BF8 in 0.85% NaCl solution for 2 h. The treated cells were then incubated with different antibiotics for 3.5 h to test antibiotic susceptibility. PAO1 persisters were found to be sensitized to Tob and Cip. The start number of persisters was 2.3×106±5.7×104/mL. (C) The QS signal 3-oxo-C12-HSL also sensitized PAO1 persisters to Cip. The same procedure as shown in Figure 3A was followed except that 3-oxo-C12-HSL was tested instead of BF8. The start number of persisters was 2.0×106±4.0×105/mL.