The microbiota conditions a gut milieu that selects for wild-type Salmonella Typhimurium virulence
Fig 7
After high-fat diet shift, selection for hilD mutants is reduced compared to streptomycin pretreated mice.
(A) Experimental scheme. (B–D) CONX were shifted from their normal plant based diet to a high-fat diet for the day before the infection (and switched back to the normal diet) with a 100:1 mixture of wild-type S. Typhimurium vs. S.TmhilD (orange symbols; 5 × 107 CFU, by gavage; n = 17 mice 2 independent experiments). The equivalent data for streptomycin pretreated mice is shown as a control (black symbols; re-plotted from Fig 4A). (B) Total Salmonella loads detected in the feces by selective plating. Dotted lines indicate the detection limit. Colored lines connect the medians. (C) Normalized C.I. as determined using MacConkey plates with selective antibiotics for wild-type S. Typhimurium vs. S.TmhilD. The dotted line indicates a C.I. of 1. (D) An ELISA for fecal lipocalin-2 was used to compare gut inflammation between the 2 groups. The data shown was obtained from 2 independent experiments including comparing both groups. Two-tailed Mann–Whitney U tests were used for statistical analysis (p ≥ 0.05 not significant (ns), p < 0.05 (*), p < 0.01 (**), p < 0.001 (***), p < 0.0001 (****)). Source data can be found in S1 Data file.