Figure 4.

Staphyloxanthin photolysis transiently elevates MRSA membrane permeability and is unable to eradicate MRSA completely. a) Log change in MRSA colony‐forming units (CFU mL⁻¹) after treatment with 460 nm light at different doses. Intensity: 60 mW cm⁻², N = 3. b) Growth curves of MRSA after no treatment (control) or treatment with 120 J cm⁻² 460 nm light irradiance (N = 6). c) MRSA CFU mL⁻¹ after no treatment (control) or treatment with 120 J cm⁻² 460 nm light irradiance, and 30 min culture in TSB medium after 120 J cm⁻² 460 nm light irradiance (N = 3). d) Confocal laser scanning imaging of membrane permeability after no treatment (control) or treatment with 120 J cm⁻² 460 nm light, and 30 min culture in TSB medium after 120 J cm⁻² 460 nm light irradiance. Scale bar = 10 µm. Green: intact membrane; Red: damaged membrane. e) Statistical analysis of cell membrane permeability for (d). N _Green and N _Red are the number of MRSA with intact membrane and damaged membrane, respectively (N = 4). Error bars show standard error of the mean (SEM). Unpaired two‐tailed t‐test (***: p < 0.001, **: p < 0.01, ns: not significant).