Extended Data Fig. 1: Characteristics of the basal-out enteroid infection model for early Shigella colonization of human intestinal epithelium.
(Extended Data Fig) Representative image showing a BO enteroid suspension culture as it appears before infection. (b) Shigella CFU counts upon coinfection of BO enteroids with a mix of wt and ΔmxiD (non-invasive) strains for 2 h and 6 h at MOI 40. CFU counts come from 5 biological replicates pooled from 2 independent experiments. Data shown as Mean +/- SD. Significance determined by two-sided Mann-Whitney U-test; **p < 0.01. (c) Shigella CFU counts upon coinfection of Caco-2 cells with a mix of wt and ΔmxiD (non-invasive) strains for 2 h and 6 h at MOI 40. CFU counts come from 7 biological replicates pooled from 2 independent experiments. Data shown as Mean +/- SD. Significance determined by two-sided Mann-Whitney U-test; **p < 0.01; ***p < 0.001. (d) Graph showing the number of generations (left panel) and the generation time (right panel) for Shigella intracellular populations in BO enteroids and Caco-2 cells between 2 and 6 h pi. Number of generations was calculated using CFUs counts from Extended Data Fig. 1b-c. Data shown as Mean +/- SD. Significance determined by two-sided Mann-Whitney U-test; **p < 0.01. (e) Representative time-lapse series of BO enteroids stained with DRAQ7 and treated as following: uninfected (first row); uninfected with addition of saponin after 4 h (second row) and, infected with Shigella wt containing the cytosolic reporter puhpT-GFP at MOI 40 (third row). Experiments were repeated 4 times with imaging of at least 10 enteroids/experiment. Roman numbers represent five different examples of infection foci. Scale bar: 50 µm.
