Fig. 2

Micro-injection of calibrated inocula of Staphylococcus aureus in the mouse ear pinna. a–c Reconstituted confocal images of the mouse ear pinna tissue showing the maximal projection intensities of the EGFP signal. LyM-EGFP transgenic mice were micro-injected with TS culture medium (a) or S. aureus mCherry-LYO-S2 in its planktonic (b) or biofilm (c) form at early (4–7 hpi) and late time points (after 24 hpi). The EGFP fluorescence (green) signal corresponds to phagocytic cells (neutrophils and macrophages). The yellow line indicates the ROI where the “Sum of EGFP fluorescence intensities” was measured. Scale bar: 2 mm. One representative experiment is shown for each group of mice from four independent experiments. d Ratio of the sum of EGFP fluorescence intensities to ROI area. Data are expressed as median and interquartile ranges for four mice per group