Figure 4.

A bacterial cell wall component of Kpn KPC ST258 inhibits ROS generation. Bacterial extracts (BE) from Kpn KPC ST258 or Eco were obtained and PMN were incubated for 30 min with these BE (10 μg/mL of total protein) in the presence or absence of fMLP (10⁻⁷ M). (A) ROS generation. The percentage of DHR+ PMN was determined by flow cytometry. n = 10. Results were expressed as the mean ± SEM. ^*p < 0.05 vs. untreated (-); # p < 0.05 vs. fMLP⁻⁷; Δp < 0.05 vs. Kpn KPC ST258 BE + fMLP⁻⁷. Lower panel: Representative histograms of SSC vs. DHR. (B) FSC increase. The percentage of PMN that increased their FSC was determined by flow cytometry. n = 10. Results were expressed as the mean ± SEM. ^*p < 0.05 vs. (-). Lower panel: Representative dot-plots of SSC vs. FSC profiles. (C) CD11b expression. The MFI of the adhesion marker CD11b was determined by flow cytometry and expressed as the relative fluorescence (RF) of the MFI of the different treatments with respect to untreated PMN. n = 10. Results were expressed as the mean ± SEM; ^*p < 0.05 vs. (-). Right panel: Representative histograms of CD11b expression. (D) H₂O₂ degradation over time. The absorbance at 240 nm was recorded for H₂O₂ (0.036% v/v) in the presence of catalase (10 U) or Kpn KPC ST258 BE (10 μg/mL of total protein). n = 3.