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:RNA from in vitro grown Salmonella typhimurium is compared with RNA extracted from Salmonella typhimurium from infected chick caecums using a common DNA reference. Keywords: Disease state analysis, infected versus uninfected, common reference Five replicates from infected chick caecal contents compared to a common reference. Three replicates from in vitro grown Salmonella compared to a common reference. The common reference was genomic DNA and always occupies the Cy3 channel (channel 2).
Project description:Emerging data has highlighted the importance of short-chain fatty acids (SCFAs) on ruminal microbiome and derived metabolism profiling, and ruminal epithelial health and nutritional absorption in ruminants. However, little is known about the roles of SCFAs on ileal microbiome profiles. Here, we combined infusion of three SCFAs, to study their different roles in ileal microbiome succession profiling using a in vivo goat model.
Project description:The increasing cost of conventional feedstuffs has bolstered interest in genetic selection for digestive efficiency (DE), a component of feed efficiency, assessed by apparent metabolisable energy corrected to zero nitrogen retention (AMEn). However, its measurement is time-consuming and constraining, and its relationship with metabolic efficiency poorly understood. To simplify selection for this trait, we searched for indirect metabolic biomarkers through an analysis of the serum metabolome using nuclear magnetic resonance (1H NMR). A partial least squares (PLS) model including six amino acids and two derivatives from butyrate predicted 59% of AMEn variability. Moreover, to increase our knowledge of the molecular mechanisms controlling DE, we investigated 1H NMR metabolomes of ileal, caecal, and serum contents by fitting canonical sparse PLS. This analysis revealed strong associations between metabolites and DE. Models based on the ileal, caecal, and serum metabolome respectively explained 77%, 78%, and 74% of the variability of AMEn and its constitutive components (utilisation of starch, lipids, and nitrogen). In our conditions, the metabolites presenting the strongest associations with AMEn were proline in the serum, fumarate in the ileum and glucose in caeca. This study shows that serum metabolomics offers new opportunities to predict chicken DE.