Fig. 2: EHEC O157:H7 utilizes L-malate as an important nutrient for fumarate respiration during intestinal colonization.

a–c Competition index (CI) analysis between O157 WT and its mutant or complemented strains. Groups of infant rabbits were intragastrically inoculated with a 1:1 ratio of the O157 WT and its mutant or complemented strains. Bacteria were recovered from colonic contents 4 d postinoculation. Competitive indexes were calculated using the relative abundance of each strain in the colonic contents, corrected by the ratio in the inoculum. d Quantification of L-malate concentrations in the colonic contents obtained from infant rabbits fed an L-malate-free diet or an L-malate-rich diet. e Bacterial counts recovered from colonic contents and tissues of L-malate-free diet-fed or L-malate-rich diet-fed infant rabbits infected with O157 WT. The horizontal lines indicate the geometric mean for each group. n = 7 infant rabbits per group were used. Statistical significance was assessed via the Kruskal‒Wallis test with Dunn’s post hoc test (a–c) or the two-sided Mann‒Whitney rank-sum test (d, e). Source data are included in Source Data file.