Motility assays
The previously described method was employed to evaluate the inhibition of bacterial motility on agar soft plates (Qais et al., 2019). To assess motility, 0.5% LB agar plates were prepared with varying concentrations of chitosan extract (10 and 100 μg/mL). A 5 µL overnight culture was spot-inoculated at the center of each plate, which was subsequently incubated for 18 hours. Additionally, swimming motility was evaluated using 0.3% LB agar plates, following the same procedure. The diameter of the swarmed or swam area was measured and reported in millimeters.