Extra-intestinal spread of <i>C</i>. <i>jejuni</i> to edible tissues at 11 DPI.

<p>Extra-intestinal spread of <i>C</i>. <i>jejuni</i> to edible tissues at 11 DPI.</p

Ileal colonisation of two commercial broiler lines at 11DPI.

<p>Ileal colonisation of two broiler lines, A (closed circles) and B (open circles) by four <i>C</i>. <i>jejuni</i> strains. Bars represent the median value for each group. Asterisks show statistically significant differences in colonisation levels between the two broiler breeds as assessed by Mann Whitney U test (** p = 0.079; § p = 0.006; ‡ p = 0.001).</p

Colonisation dynamics of <i>C</i>. <i>jejuni</i> strains in two commercial broiler lines at 4DPI.

<p>Colonisation dynamics of <i>C</i>. <i>jejuni</i> strains in two commercial broiler lines at 4DPI.</p

Caecal colonisation of two commercial broiler lines at 11DPI.

<p>Caecal colonisation of two broiler lines, A (closed circles) and B (open circles) by four <i>C</i>. <i>jejuni</i> strains. Bars represent the median value for each group. Asterisks show statistically significant differences in colonisation levels between the two broiler breeds as assessed by Mann Whitney U test (* p = 0.0024).</p

Mortality of <i>Galleria mellonella</i> larvae at 48h post infection with <i>C</i>. <i>jejuni</i>.

<p>Mortality as measured by larval viability 48 hours after challenge. Data presented based on six repeats of infection experiment using 10 larvae per isolate. Asterisks show statistically significant differences in mortality rate between <i>C</i>. <i>jejuni</i> 13126 and other strains as assessed by one-way ANOVA with Tukey post-hoc test (* p = 0.02; ** p = 0.001).</p

<i>C</i>. <i>jejuni</i> 13126 displays enhanced invasiveness in Caco-2 cells.

<p>Invasion of Caco 2 cells by five <i>C</i>. <i>jejuni</i> strains was examined. Asterisks show statistically significant differences in invasion levels between <i>C</i>. <i>jejuni</i> 13126 and the other four strains as assessed by one-way ANOVA (** p = 0.01).</p

reid_openscience_data

These cytokine data are based on total RNA samples taken from caecal tissue of commercial broilers, which were held under laboratory conditions. The birds were challenged with the pathogen Campylobacter jejuni. The results are expressed as fold changes in corrected target gene expression in infected birds relative to controls

B lymphocytes play a limited role in clearance of Campylobacter jejuni from the chicken intestinal tract

Campylobacter jejuni is the leading cause of foodborne bacterial gastroenteritis with contaminated poultry meat its main source. Control of C. jejuni is a priority for the poultry industry but no vaccines are available and their development hampered by poor understanding of the immunobiology of C. jejuni infection. Here we show the functional role of B lymphocytes in response to C. jejuni in the chicken through depletion of the B lymphocyte population (bursectomy) followed by challenge. B lymphocyte depletion has little effect on bacterial numbers in the ceca, the main site of colonisation, where C. jejuni persist to beyond commercial slaughter age, but reduces clearance from the small intestine. In longer-term experiments we show antibody leads to reduction in C. jeuni numbers in the ceca by nine weeks post infection. Whilst we did not examine any protective role to re-challenge, it illustrates the difficulty in producing a vaccine in a young, immunologically naïve host. We believe this is first study of functional immunity to C. jejuni in chicken and shows antibody is ineffective in clearing C. jejuni from the ceca within the production lifetime of chickens, although is involved in clearance from the small intestine and longer-term clearance from the ceca