Fig. 7. The eFA incorporation defect of mFabT confers a selective advantage in saturated eFA environments, and in a simulated muscle biotope.

a Growth of WT (left), and mFabT (right) in THY supplemented with 100 μM saturated FAs, C14:0 or C16:0 and BSA 0.025%. b, Left, Incorporation of exogenous C14:0 and C16:0 from cultures described in (a). Right, Percent C14:0 and C16:0 incorporation from growth experiments. In (a) and (b), data are presented as mean values +/- SEM based on 3 biological replicates; b 2-way ANOVA, Bonferroni post-test. Significant p-values are shown. WT (black lines, white bars) and mFabT (green lines and bars). c, d Strains were spread on solid BHI medium. Pellets of organic ground bovine meat (~15% fat), used as muscle source, were placed on the bacterial lawns. Plates were photographed 36 h after incubation at 37 °C. Arrowheads indicate zones of inhibition (white) or growth (black) around muscle sources. c, Upper WT^eryR-igfp and mFabT^eryR-igfp strains were grown in BHI Ery 5, and plated on the same solid medium. Lower, schematic representation of GAS strain growth inhibition and stimulation by muscle. d mFabT^eryR-igfp was grown in BHI Ery 5 medium containing C17:1 as FA source, without or with platensimycin to turn off FASII. Cultures were then plated on respectively the same solid medium. For c and d, N = 4 and N = 2 respectively, corresponding to biologically independent experiments. Source data for (a) and (b) are provided as a Source Data file.