(A) C57BL/6J mice harbouring the sDMDMm2 microbiota were colonized with S. aureus under axenic conditions, inoculated 3 weeks later with fixed bacteria (108 CFU in 10 µl PBS) or PBS and analyzed for skin infiltrating PML, Ly6Chi monocytes and skin CXCL1 levels after 4 hr (n: 10–12 biological replicates representing two independent experiments). (B) RNA expression of sorted CD64hi dermal Mφ from S. aureus infected mice or naïve mice analyzed 3, 6 and 12 weeks after infection (n:2–4 biological replicates from two independent experiments). (C) Wt mice were treated i.v. with PKH26 red fluorescent cell linker. One week after labeling, mice were infected i.d. with S. aureus. After another 1 and 3 weeks, the contribution of PHK26 positive to all CD64hi dermal Mφ was quantified (n: two biological replicates per time point from two independent experiments). (D) B6-CD45.1 mice were transplanted with 107 bone marrow cells from B6-CD45.2 congenic mice after fractional lethal irradiation. 8 weeks after transplantation dermal Mφ chimerism was determined by flow cytometry analysis using CD45.1 and CD45.2 antibodies (d0) or infected with S. aureus (107 CFU in 10 µl PBS) intradermally in the left ear. At the indicated time points the mice were sacrificed and dermal Mφ chimerism was determined by flow cytometry in the infected (S.a.) and uninfected ears (-). (n: three biological replicates for d0, and four biological replicates for all other groups). (E) Wt and Ccr2-/- mice were i.d. infected with S. aureus (107 CFU in 10 µl PBSl) and i.d. (re-)infected 3 or 6 weeks later with the same amount of bacteria and analyzed for bacterial load after an additional 5 days (n: three biological replicates from one independent experiment for the 6 week time points). Data were analyzed using two tailed unpaired T test. Error bars are mean ± SEM. *p<0.05, **p<0.01, ***p<0.001.