Figure 2: “Non-toxic” S. aureus strains and CoNSS. epidermidis induce IL1-ß after phagocytosis
After phagocytosis and lysostaphin/gentamicin treatment for 1 h (t0) THP-1-CWT cells (A, B, C ) or hMDM (D, E, F ) were further incubated for 3 h or 24 h in medium containing gentamicin to kill extracellular/escaped bacteria. At indicated time points, the cells were lysed and bacterial CFU determined. Intracellular bacteria are expressed as the ratio of CFU at t3 or t24 to CFU at t0 (A, D ). Membrane integrity of the THP-1- CWT cells were assessed by LDH-assay (B, E ) and IL-1ß by ELISA (C, F ).
The data represent at least three biological replicates. Significance was determined by one-way analysis of variance with Tukey‘s multiple comparison post-test.