Project description:Campylobacter jejuni is a major zoonotic pathogen transmitted to humans via the food chain. C. jejuni is prevalent in chickens, a natural reservoir for this pathogenic organism. Due to the importance of macrolide antibiotics in clinical therapy of human campylobacteriosis, development of macrolide resistance in Campylobacter has become a concern for public health.To facilitate understanding the molecular basis associated with the fitness difference between Erys and Eryr Campylobacter, we compared the transcriptomes between ATCC 700819 and its isogenic Eryr transformant T.L.101 using DNA microarray.
Project description:Campylobacter, a major foodborne pathogen, is increasingly resistant to macrolide antibibotics. Previous findings suggested that development of macrolide resistance in Campylobacter requires a multi-step process, but the molecular mechanisms involved in the process are not known. In our study, erythromycin-resistant C. jejuni mutant (R) was selected in vitro by stepwise exposure of C. jejuni NCTC11168(S) to increasing concentrations of erythromycin.The resistant were subjected to microarray and the the global transcriptional profile was analyzed. In this series, DNA microarray was used to compare the gene expression profiles of the macrolide-resistant strain with its parent wild-type strain NCTC11168. A large number of gene showed significant changes in R. The up-regulated genes in the resistant strains are involved in miscellaneous periplasmic proteins, efflux protein and putative aminotransferase, while the majority of the down-regulated genes are involved in electron transport, lipoprotein, heat shock protein and unknown function proteins. The over-expression of efflux pump and periplasmic protein was involved in the development of resistance to macrolide in C. jejuni. An eight chip study using total RNA recovered from four separate resistant-type cultures of Erythrocin-resistant Campylobacter jejuni NCTC111168 (R) and four separate cultures of Campylobacter jejuni NCTC111168 (S). Each chip measures the expression level of 1634 genes from Campylobacter jejuni NCTC11168.
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 major zoonotic pathogen transmitted to humans via the food chain. C. jejuni is prevalent in chickens, a natural reservoir for this pathogenic organism. Due to the importance of macrolide antibiotics in clinical therapy of human campylobacteriosis, development of macrolide resistance in Campylobacter has become a concern for public health.To facilitate understanding the molecular basis associated with the fitness difference between Erys and Eryr Campylobacter, we compared the transcriptomes between ATCC 700819 and its isogenic Eryr transformant T.L.101 using DNA microarray. The design utilized an available two color microarray slide for the entire transcriptome of Campylobacter jejuni. Four hybridizations were performed each with independently extracted samples of either macrolide susceptible ATCC 700819 cDNA samples or its isogenic Eryr transformant T.L.101 cDNA samples. A dye swap was utilized to help minimize dye dependent bias. Thus, there were four biological replicates of each sample.
Project description:Campylobacter, a major foodborne pathogen, is increasingly resistant to macrolide antibibotics. previous findings suggeted that development of macrolide resistance in campylobacter requires a multi-step process, but the molecular mechanisms involved in the process are not known. In our study, multiple seriess of macrolide-resistant C. jejuni mutants were selected in vitro by stepwise exposure of C. jejuni 81-176 to increasing concentrations of erythromycin and tylosin. A set of the selected resistance were subjected to microarray and the the global transcriptional profile was analyzed. In this sery, DNA microarray was used to compare the gene expression profiles of macrolide resistant strains (76E2, 76E8 and 76E64) with its parent wild-type strain C. jejuni 81-176. This assay identified a large number of genes that showed >1.5 fold changes (q-value<0.1) in expression in the macrolide resistant strains. The up-regulated genes are involved in surface structure,ribosomal, heat shock and some specific Misc memerbrane , while the majority of the down-regulated genes are involved in energy metabolism, amino acid biosynthesis. The over-expression of genes involved in surface structure and Misc memerbrance was associated with the development of intermedial-level resistance to macrolide in campylobacter 81-176. Keywords:intermedial-level macrolide resistant C. jejuni selected from C. jejuni 81-176. step-wise selection.
Project description:Campylobacter, a major foodborne pathogen, is increasingly resistant to macrolide antibibotics. previous findings suggeted that development of macrolide resistance in campylobacter requires a multi-step process, but the molecular mechanisms involved in the process are not known. In our study, multiple seriess of macrolide-resistant C. jejuni mutants were selected in vitro by stepwise exposure of C. jejuni 81-176 to increasing concentrations of erythromycin and tylosin. A set of the selected resistance were subjected to microarray and the the global transcriptional profile was analyzed. In this sery, DNA microarray was used to compare the gene expression profiles of macrolide resistant strains (76E2, 76E8 and 76E64) with its parent wild-type strain C. jejuni 81-176. This assay identified a large number of genes that showed >1.5 fold changes (q-value<0.1) in expression in the macrolide resistant strains. The up-regulated genes are involved in surface structure,ribosomal, heat shock and some specific Misc memerbrane , while the majority of the down-regulated genes are involved in energy metabolism, amino acid biosynthesis. The over-expression of genes involved in surface structure and Misc memerbrance was associated with the development of intermedial-level resistance to macrolide in campylobacter 81-176. Keywords:intermedial-level macrolide resistant C. jejuni selected from C. jejuni 81-176. step-wise selection. The design utilized an available two color microarray slide for the entire transcriptome of Campylobacter jejuni. Four hybridizations were performed each with independently extracted samples of either macrolide susceptible C. jejuni 81-176 cDNA samples or macrolide resistant C. jejuni cDNA samples. A dye swap was utilized to help minimize dye dependent bias. Thus there were three to four biological replicates of each sample.
Project description:Campylobacter jejuni is the most prevalent cause of foodborne bacterial enteritis worldwide. This study aims at the characterisation of pathomechanisms and signalling in Campylobacter-induced diarrhoea in the human mucosa. During routine colonoscopy, biopsies were taken from patients suffering from campylobacteriosis. RNA-seq of colon biopsies was performed to describe Campylobacter jejuni-mediated effects. Mucosal mRNA profiles of acutely infected patients and healthy controls were generated by deep sequencing using Illumina HiSeq 2500. This data provide the basis for subsequent upstream regulator analysis.
Project description:The Gram-negative bacterium Campylobacter jejuni is a major cause of foodborne disease in humans. After infection, C. jejuni rapidly colonizes the mucus layer of the small and large intestine and induces a potent pro-inflammatory response characterized by the production of a large repertoire of cytokines, chemokines, and innate effector molecules, resulting in (bloody) diarrhea. The virulence mechanisms by which C. jejuni causes this intestinal response are still largely unknown. Here we show that C. jejuni releases a potent pro-inflammatory compound into its environment, which activates an NF-B-mediated pro-inflammatory response including the induction of CXCL8, CXCL2, TNFAIP2 and PTGS2. This response was dependent on a functional ALPK1 receptor and independent of Toll-like Receptor and Nod-like Receptor signaling. Chemical characterization, inactivation of the heptose-biosynthesis pathway by the deletion of the hldE gene and in vitro engineering identified the released factor as the LOS-intermediate ADP-heptose and/or related heptose phosphates. During C. jejuni infection of intestinal cells, the ALPK1-NF-kB axis was potently activated by released heptose metabolites without the need for a type III or type IV injection machinery. Our results classify ADP-heptose and/or related heptose phosphates as a major virulence factor of C. jejuni that may play an important role during Campylobacter infection in humans.
Project description:Expression arrays comparing Campylobacter jejuni NCTC11168 during growth in the cecum of germ-free C57 BL/6 IL-10 knockout mice to C. jejuni NCTC11168 during growth in Bolton broth.
Project description:Campylobacter jejuni is the prevalent cause of bacterial gastroenteritis in human worldwide. The ability to survive stomach acidity is a fundamental requirement for C. jejuni to colonize the host and cause disease. However, the mechanism of C. jejuni acid survival is still unknown. Herein, we demonstrated that C. jejuni is able to survive acidic conditions at pH 4 up to 8 min without a drop in viability. The acid stimulon of C. jejuni 81-176 revealed the up-regulation of many genes important for Campylobacter acid survival such as heat shock genes and genes involved in energy metabolism. On the other hand, the repression of ribosomal genes highlights the ability of C. jejuni to direct its machinery to survive stressful conditions. Prior acid exposure cross-protected C. jejuni against oxidative stress suggesting an overlap in C. jejuni’s responses to various stresses. Interestingly, the induced expression of virulence genes in C. jejuni upon acid exposure such as the Campylobacter invasion antigen (ciaB) indicates that acid stress plays a role in C. jejuni host pathogenesis. Acid exposure significantly enhanced C. jejuni pathogenesis in both eukaryotic cells and G. melonella. To the best of our knowledge, this is the first study characterizes the influence of acid stress on C. jejuni pathogenesis in an infection model. Altogether, this study uncovers the transcriptional profile of C. jejuni in response to acidic conditions as those encountered in the stomach. In addition, our results demonstrate that acid stress jump-starts C. jejuni for efficient gut colonization and host pathogenesis. Campylobacter jejuni is the prevalent cause of bacterial gastroenteritis in human worldwide. The ability to survive stomach acidity is a fundamental requirement for C. jejuni to colonize the host and cause disease. However, the mechanism of C. jejuni acid survival is still unknown. Herein, we demonstrated that C. jejuni is able to survive acidic conditions at pH 4 up to 8 min without a drop in viability. The acid stimulon of C. jejuni 81-176 revealed the up-regulation of many genes important for Campylobacter acid survival such as heat shock genes and genes involved in energy metabolism. On the other hand, the repression of ribosomal genes highlights the ability of C. jejuni to direct its machinery to survive stressful conditions. Prior acid exposure cross-protected C. jejuni against oxidative stress suggesting an overlap in C. jejuni’s responses to various stresses. Interestingly, the induced expression of virulence genes in C. jejuni upon acid exposure such as the Campylobacter invasion antigen (ciaB) indicates that acid stress plays a role in C. jejuni host pathogenesis. Acid exposure significantly enhanced C. jejuni pathogenesis in both eukaryotic cells and G. melonella. To the best of our knowledge, this is the first study characterizes the influence of acid stress on C. jejuni pathogenesis in an infection model. Altogether, this study uncovers the transcriptional profile of C. jejuni in response to acidic conditions as those encountered in the stomach. In addition, our results demonstrate that acid stress jump-starts C. jejuni for efficient gut colonization and host pathogenesis.