FIG 5.

C. amalonaticus^C3H outcompetes C. rodentium. (A, left) Representative BLI of cocultures of ICC180 and ICC169 or C. amalonaticus^C3H (CA). The number on the left of the cultures indicates the dilution factor. (Right) Graph showing the quantification of BL from the 10⁻³ culture spot of the indicated coculture from three biological repeats. (B) Fluorescence microscopy of cocultures of C. rodentium (ICC169; CR) and C. amalonaticus^C3H (CA) expressing RFP or GFP from a plasmid as indicated after 24 h of growth on LB agar. Scale bar = 1,000 μm. (C) Quantification of ICC180 CFU at 0, 5, and 24 h after coincubation with ICC169 or C. amalonaticus^C3H (D, left) Representative BLI of ICC180 grown with ICC169 or C. amalonaticus^C3H separated by a filter with 5-μm or 0.1-μm pores or not separated by a filter. (Right) Graph showing the quantification of BL from the culture spots shown on the left from three biological repeats. (A, C, D) *, P < 0.05; **, P < 0.01; ***, P < 0.001 (as determined by Student’s unpaired two-tailed t test). (A, D) Color scale bars indicate radiance (photons per second per square centimeter per surface radiance). (E) C. rodentium colonization of AIBC mice before (Pre) C. amalonaticus^C3H inoculation (42 DPI) and 7 days after (post) the first C. amalonaticus^C3H inoculation (53 DPI). Five mice from one biological repeat were used. LoD, limit of detection.