The <i>csB</i> mutant shows increased colonisation in a mouse model of gastrointestinal tract infection, but no difference in weight loss, compared to the wild-type strain.

<p>Mice orally infected with spores from the <i>csB</i> mutant show high levels of spores shed from the gastrointestinal tract for the duration of the experiment (A). Mice were administered either wild-type (red circle), <i>csA</i> mutant (green square), <i>csB</i> mutant (blue arrowhead) or <i>csB</i> complemented (purple diamond) spores. Faecal spore load was determined for each mouse every day until 4 days post infection and is presented here with each point representing a single mouse. The results represent the average of at least four mice and error bars represent standard error of the mean. The limit of detection is shown as a dashed line (A). Mice administered wild-type spores (red) showed no difference in weight loss compared to mice administered <i>csA</i> (green) or <i>csB</i> (blue) spores or to uninfected mice (grey). The results represent the average of at least five mice and error bars represent standard error of the mean (B). The variability in faecal spore load between mice administered with the same strain was calculated by determining the deviation in faecal spore load of each mouse in comparison to the mean faecal spore load of mice administered with the same strain and is presented here as box plots with Tukey whiskers (C). Asterisks indicate statistical difference at *, <i>p</i> ≤ 0.05; **, <i>p</i> ≤ 0.01; ****, <i>p</i> ≤ 0.0001. Wild-type, WT; <i>csA</i> mutant, <i>csA</i>-M; <i>csB</i> mutant, <i>csB</i>-M; <i>csB</i> mutant complemented, <i>csB</i>-C.