Fig 5.

Viability of S. aureus 2117 and MRSA 1158c either untreated (CTRL) or in the presence of a sub-MIC of chitosan (2.6 kDa) used alone or in combination with a sub-MIC of (A) erythromycin (ERY) or (B) tilmicosin (TIL) at 10 h post-treatment. The sub-MIC concentrations are indicated on the graphs. The CFU detection limit is 10 CFU/ml. Data are presented as means with standard deviations from three independent experiments. Significant differences between the control (CTRL) and test conditions are shown (ns, non significant; *, P<0.01; ***, P<0.001; ****, P<0.0001 as determined by using one way ANOVA with Tukey’s multiple comparison test.