Fig 2: Cytotoxicity of PolaR testing on mammalian cells in vitro. FaDu (ATCC HTB-43), RAW 264.7 (ATCC TIB-71) and A549 (ATCC CCL-185) cell lines were treated with 0.1, 1, 10 or 100 µg/mL of PolaR. PBS of the same volume served as a control. Cells were incubated with PolaR for 48 h (ns p > 0.2).

Fig 3: Cell death induction by S. aureus isolates from control (MIN) and CRS (CSS) donors. (A) Staphylococcal isolates from control and CRS donors from the main clonal complexes (CC7, CC30, CC45 and CC15) were selected. Human epithelial lung A549 cells (ATCC: CCL-185) were infected, and cell death induction was measured by staining the cells with propidium iodide after 24 h. (B) Proportions of dead cells obtained for staphylococcal isolates from the control and CRS groups. Differences between the proportions of dead cells infected with isolates from both groups were analysed by unpaired t tests (* p < 0.05, ** p < 0.01 and *** p < 0.001). Data are presented as the average of triplicate determinations, and error bars represent the standard deviation.

Fig 4: IL-6 induced by S. aureus-infected cells. Staphylococcal isolates from control and CRS donors were selected from the major clonal complexes (CC7, CC30, CC45 and CC15). Human lung epithelial A549 cells (ATCC: CCL-185) were infected and the supernatant was analysed by ELISA at 24 h post-infection. Differences in IL-6 release between the isolates from each pair infected were analysed by unpaired t tests (* p < 0.05, ** p < 0.01, *** p < 0.01). Data are presented as the mean of triplicate determinations, and error bars represent the standard deviation.

Fig 5: Comparison of percent cell viability shown by MNBM against A549 cells (ATCC: CCL-185) with 0.1% DMSO (as negative control) and Fisetin 75 μM (as positive control) analyzed by in vitro MTT assay (*Significant differences are indicated by P < 0.05 as compared with controls.)