Project description:Campylobacter jejuni is a common cause of diarrheal disease worldwide. Human infection typically occurs through the ingestion of contaminated poultry products. We previously demonstrated that an attenuated Escherichia coli live vaccine strain expressing the C. jejuni N-glycan on its surface reduces the Campylobacter load in more than 50% of vaccinated leghorn and broiler birds to undetectable levels (responder birds), whereas the remainder of the animals were still colonized (non-responders). To understand the underlying mechanism, we conducted 3 larger scale vaccination and challenge studies using 135 broiler birds and found a similar responder/non responder effect. The submitted data were used for a genome-wide association study of the chicken responses to glycoconjugate vaccination against Campylobacter jejuni.
Project description:Campylobacter jejuni is a human pathogen which causes campylobacteriosis, one of the most widespread zoonotic enteric diseases worldwide. Most cases of sporadic C. jejuni infection occur through the handling or consumption of undercooked chicken meat, or cross-contamination of other foods with raw poultry fluid. A common practice to combat Campylobacter infection is to treat chickens with chlorine which kills the microbe. This analysis aimed to elucidate the transcriptomic response of Campylobacter jejuni treated with hypochlorite through Illumina sequencing. C. jejuni was grown and treated with hypochlorite. Samples were taken 5, 20 and 45 min after treatment for RNAseq analysis.The data generated were compared to the transcriptome pre-exposure to determine C. jejuni's response to hypochlorite.
Project description:Campylobacter jejuni (C. jejuni) is a zoonotic pathogen that causes human diarrhea worldwide. Chickens are a natural reservoir of C. jejuni. Understanding the host response to C. jejuni infection at the molecular level will lay the foundation to control human campylobacterosis by reducing food contamination. Two distinct genetic lines, resistant (line A) and susceptible (line B) to C. jejuni colonization, were utilized to profile the host response to C. jejuni infection using an Agilent chicken 44K microarray. Day-old chickens were challenged orally with C. jejuni and spleens collected for total RNA 7 days post-challenge. Twenty infected samples with highest (a) or lowest bacterial number (b) in cecal content and twenty non-infected (c) in each line were randomly pooled into four biological replicates. The pair comparisons among these three groups within each line were analyzed. The signal intensity of each gene was normalized using LOWESS method. A mixed model was used to identify differentially expressed genes by SAS (P < 0.001). This was opposite to previous cecal tonsil microarray result. There were 468, 743, and 939 genes differentially expressed between groups a and c, groups a and b, and groups b and c in line A, respectively, and 201, 37, 126 genes in line B, respectively. More differentially expressed genes in spleen in line A than in line B were found. The results indicated that significantly different response to C. jejuni infection occurred between resistant and susceptible chicken lines, and the effects of interaction between genetics and tissue should be considered.
Project description:Chromosomal structural variation can cause alterations in gene dosage and gene regulation between genomes. Structural variants producing a change in the number of copies of a genomic region are termed copy number variants (CNVs). CNVs have been demonstrated to have causative effects on both Mendelian and complex traits, including susceptibility to infectious diseases. We are interested in mapping CNVs to domesticated chicken breeds to help determine structural variation between genomes that influences economically important traits. For this study, Fayoumi, Leghorn, Line A broiler and Line B broiler chicken were chosen. Fayoumi and Leghorn chickens were selected as these two breeds harbor different responses certain pathogens like Avian Influenza Virus and coccidiosis; Broiler Line A and Line B indivduals were chosen as they harbor different intestinal colonization loads to the bacterium Campylobacter jejuni. Campylobacter genetic Line A and genetic Line B are from a commercial producer have been previously described as either resistant (Line A) or susceptible (Line B). Highly inbred chicken lines Fayoumi M15.2 (n=6) and Leghorn GHs6 (n=6) and broilers from Line A (n=24 individuals in pools of 4) and Line B (n=24 individuals in pools of 4)were subjected to array Comparative Genomic Hybridization (aCGH). Each sample was normalized to a Red Jungle Fowl reference. CNVs for each individual and between lines were determined. The major goal of this study was to discover and characterize CNVs in chickens to further narrow in on Quantitative Trait Loci (QTLs) affecting disease response. For the test DNA in Fayoumi and Leghorn, samples from 6 inbred Fayoumi and 6 inbred Leghorn individuals were used; For the test DNA in the Campylobacter genetic lines, samples from 24 individual broilers of Line A (in pools of 4) and 24 individual broilers of Line B (in pools of 4) were used. For the reference DNA, Red Jungle Fowl line UCD001 was used from a self-self hybridization.
Project description:The gut of chicken is mostly colonised with Campylobacter jejuni and with 100 fold less C. coli. The competitive ability of C. coli OR12 over C. jejuni OR1 has been examined in experimental broiler chickens following the observation that C. coli replaced an established C. jejuni intestinal colonisation within commercial chicken flocks reared outdoors (El-Shibiny, A., Connerton, P.L., Connerton, I.F., 2005. Enumeration and diversity of campylobacters and bacteriophages isolated during the rearing cycles of free-range and organic chickens. Applied Environmental Microbiology. 71, 1259-1266).
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:Campylobacter jejuni is the leading cause of foodborne human gastroenteritis in the developed world. Infections are largely acquired from poultry produced for human consumption and poor food handling is thus a major risk factor. In this study, C. jejuni were exposed to growth in a number of enviornmental conditions representative of the human gastrointestinal tract, including 0.1% deoxycholate (DOC), under iron limitation (induced by 1 mM deferroxamine, in the presence of chicken 'juice' or 'exudate (the thaw water of frozen commerical chicken products) and in the presence of mammalian mucin.
Project description:The existence of conventional dendritic cells (cDCs) has not yet been demonstrated outside mammals. In this paper, we identified bona fide cDCs in chicken spleen. Comparative profiling of global and of immune response gene expression, morphology, and T cell activation properties show that cDCs and macrophages (MPs) exist as distinct mononuclear phagocytes in chicken, resembling their human and mouse cell counterparts. Using computational analysis, core gene expression signatures for cDCs, MPs, T and B cells across chicken, human and mouse were established, which will facilitate the identification of these subsets in other vertebrates. Overall this study, by extending the newly uncovered cDC and MP paradigm to chicken, suggests that the generation of these two phagocyte lineages occurred before the reptile to mammal and bird transition in evolution. It opens avenues for the design of new vaccines and neutraceuticals that are mandatory for the sustained supply of poultry products in the expanding human population.