FIGURE 13.

Log reduction of the viable counts (colony-forming unit/ml) of Pseudomonas aeruginosa PAO1 (A) and Staphylococcus aureus (B) biofilms after the treatment with different concentrations of polymyxin B (50, 100, and 200 μM) and vancomycin (50, 100, and 200 μM), respectively. The black columns represent the log reduction achieved in monoculture conditions, while the orange columns represent the log reduction in co-culture conditions. The results are expressed as the mean of three or more biological repetitions with their SD (Student’s t-test; *p < 0.05 and **p < 0.01).