Project description:Campylobacter jejuni is the major cause of acute gastroenteritis in the developed world. It is usually acquired through contaminated poultry as C. jejuni causes a silent asymptomatic infection of the chicken. Pathogens face different sources of stress during its transit through the gut. In this study, we describe the ability of C. jejuni to survive nitrosative stress at very low oxygen levels that reflect those in hypoxic gut environments. Specifically, we here explore an innovative model of signal recognition during colonization. We use a diffusion capsule to feed small, diffusible molecules from chicken caecal matter into a microaerobic C. jejuni culture to study the transcriptomic changes mounted as response to chemical signals present in the chicken gut. We find that in early stages of exposure to the caecal contents (10 min) the dual component colonization regulator, dccR, plays an important yet not fully understood role. Although the caecal material contains cyanide derived from plant sources, we find no role for a truncated globin (encoded by ctb), which has previously been implicated in resistance to this haem ligand.
Project description:RNAseq analysis of caecal tissue from 14 C. jejuni-susceptible and 14 C. jejuni-resistant birds from a single population of infected chickens was conducted in order to identify gene expression associated with resistance to colonization. Significantly higher expression of genes involved in the innate immune response, cytokine signaling, B cell and T cell activation and immunoglobulin production, as well as the renin-angiotensin system was observed in resistant birds. A population of 255 Barred Rock chickens were orally inoculated with C. jejuni and their caecal colonization levels estimated 48 hours post-inoculation. Caecal samples from 14 birds with no colonization and the 14 birds with the highest colonization were selected for mRNA sequencing.
Project description:RNAseq analysis of caecal tissue from 14 C. jejuni-susceptible and 14 C. jejuni-resistant birds from a single population of infected chickens was conducted in order to identify gene expression associated with resistance to colonization. Significantly higher expression of genes involved in the innate immune response, cytokine signaling, B cell and T cell activation and immunoglobulin production, as well as the renin-angiotensin system was observed in resistant birds.
Project description:Selenium (Se) is an essential cofactor of the antioxidant enzyme glutathione peroxidase beside other functions. The evaluation of optimal selenium supplementation in chicken feed and the subsequent effects on animal health and performance requires comprehensive knowledge of the overall metabolic effects of selenium. Therefore the gene expression was measured in the control group with a standard diet and in the group with a Se supplemented diet (0.5mg Se/kg diet) to determine significantly altered gene expression. The selenium was supplemented in the form of selenized yeast (Se-yeast), which mainly consists of organic Se in the form of L-selenomethionine and L-selenocysteine. The control group received a diet, which contained 70μg of Se / kg diet and the Se-yeast group 620μg of Se / kg diet (analyzed).
Project description:Selenium (Se) is an essential cofactor of the antioxidant enzyme glutathione peroxidase beside other functions. The evaluation of optimal selenium supplementation in chicken feed and the subsequent effects on animal health and performance requires comprehensive knowledge of the overall metabolic effects of selenium. Therefore the gene expression was measured in the control group with a standard diet and in the group with a Se supplemented diet (0.5mg Se/kg diet) to determine significantly altered gene expression. The selenium was supplemented in the form of selenized yeast (Se-yeast), which mainly consists of organic Se in the form of L-selenomethionine and L-selenocysteine. The control group received a diet, which contained 70μg of Se / kg diet and the Se-yeast group 620μg of Se / kg diet (analyzed). The one-day old broiler chicks were separated into two groups and received the control or the Se-supplemented diet ad libitum for 35 days. After slaughter the gene expression was determined in the liver of four control and five samples from the Se-yeast group. One sample from the control group did not correspond to the quality requirements and was excluded from the analysis.
