Similar Datasets
Project description:While growing in the human intestine, C. jejuni grows within the mucus layer. The largest constituents of this layer are the large mucin glycoproteins. A transcriptomic profile of C. jejuni NCTC11168 growing in a mucin-containing minimal medium seeks to describe the effect of the presence of mucin proteins on the transcriptome of C. jejuni.
2011-04-01 | GSE28295 | GEO
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.
2016-10-01 | GSE73793 | GEO
Project description:Campylobacter jejuni effectively promotes commensalism in the intestinal tract of avian hosts and diarrheal disease in humans, yet components of intestinal environments sensed by the bacterium in either host to initiate interactions are mostly unknown. By analyzing a C. jejuni acetogenesis mutant that is defective in both converting acetyl-CoA to acetate and commensal colonization of young chicks, we discovered evidence for C. jejuni sensing spatial gradients of microbiota-derived short-chain fatty acids (SCFAs) and organic acids to modulate expression of determinants required for commensalism. We identified in C. jejuni an SCFA-influenced regulon composed by genes encoding catabolic enzymes and transport systems for amino acids C. jejuni requires for in vivo growth. Expression of these genes was reduced in the acetogenesis mutant, but restored upon supplementation with physiological concentrations of SCFAs such as acetate and butyrate that are present in the lower intestinal tract of avian and human hosts. Conversely, the organic acid lactate, which is abundant in the upper intestinal tract of these hosts where C. jejuni less efficiently colonizes reduced expression of this regulon. We propose a model whereby C. jejuni senses microbiota-produced SCFAs and lactate for spatial orientation in the avian and human host. Sensing these metabolites likely allows C. jejuni to locate preferred niches in the lower intestinal tract and induce expression of factors required for in vivo growth. Our findings provide insights into the types of signals C. jejuni monitors in the avian host for commensalism and likely in the human host to promote diarrheal disease.
2016-09-02 | GSE86327 | GEO
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.
2021-11-01 | GSE181619 | GEO
Project description:Gene content comparison of control C. jejuni subsp. jejuni strain 11168 which colonizes and causes disease in C57BL/6 IL-10-/- mice versus C. jejuni strains D6844, D6845, D6846, D6847, D6848, D6849, D0121, D0835, D2586, D2600,33560 and NW in the C57BL/6 IL-10-/- mice. Keywords: DNA/DNA comparison
2010-10-21 | GSE24764 | GEO
Project description:The species Campylobacter jejuni is naturally competent for DNA uptake; nevertheless, nonnaturally transformable strains do exist. For a subset of strains we previously showed that a periplasmic DNase, encoded by dns, inhibits natural transformation in C. jejuni. In the present study, genetic factors coding for DNase activity in absence of dns were identified. DNA arrays indicated that nonnaturally transformable dns-negative strains contain putative DNA/RNA non-specific endonucleases encoded by CJE0566 and CJE1441 of strain RM1221. These genes are located on C. jejuni integrated element 2 and 4. Expression of CJE0566 and CJE1441 from strain RM1221 and a homologous gene from strain 07479 in DNase-negative Escherichia coli and C. jejuni strains indicated that these genes code for DNases. Genetic transfer of the genes to a naturally transformable C. jejuni strain resulted in a decreased efficiency of natural transformation. Modelling suggests that the C. jejuni DNases belong to the Serratia nuclease family. Overall, the data indicate that the acquisition of prophage encoded DNA/RNA non-specific endonucleases inhibits the natural transformability of C. jejuni through hydrolysis of DNA.
2009-11-14 | GSE18399 | GEO
Project description:Major foodborne bacterial pathogens, such as Campylobacter jejuni, have devised complex strategies to establish and foster intestinal infections. For more than two decades researchers have used immortalized cell lines derived from human intestinal tissue to dissect C. jejuni-host cell interactions. Known from these studies is that C. jejuni virulence is multifactorial, requiring a coordinated response to produce virulence factors that facilitate the bacterium’s host-cell interactions. This study was initiated to identify C. jejuni proteins that contribute to adaptation to the host cell environment and cellular invasion. We demonstrated that C. jejuni responds to INT 407 and Caco-2 cells in a similar fashion at the cellular and molecular levels. Active protein synthesis was found to be required for C. jejuni to maximally invade these host cells. Proteomic and transcriptomic approaches were then used to define the protein and gene expression profiles of C. jejuni co-cultured with cells. By focusing on those genes showing increased expression by C. jejuni when co-cultured with epithelial cells, we discovered that C. jejuni quickly adapts to co-culture with epithelial cells by synthesizing gene products that enable it to acquire specific amino acids for growth, scavenge for inorganic molecules including iron, resist reactive oxygen/nitrogen species, and promote bacteria-host cell interactions. Based on these findings, we selected a subset of the genes involved in chemotaxis and the regulation of flagellar assembly and generated C. jejuni deletion mutants for phenotypic analysis. Binding and internalization assays revealed significant differences in the interaction of C. jejuni chemotaxis and flagellar regulatory mutants. The identification of genes involved in C. jejuni adaptation to culture with host cells provides new insights into the infection process.
2019-04-11 | GSE114909 | GEO
Project description:Campylobacter jejuni is a prevalent cause of bacterial gastroenteritis in humans worldwide. The mechanism by which C. jejuni survives stomach acidity remains unknown. Herein, we have demonstrated that C. jejuni with a fur deletion was more sensitive to acid than the wild-type strain. Profiling the acid stimulon of the C. jejuni ∆fur mutant allowed us to uncover Fur-regulated genes under acidic conditions. The up-regulation of heat shock genes and the down-regulation of genes involved in flagellar and cell envelope biogenesis in the fur mutant highlight the importance of Fur in Campylobacter acid survival. Interestingly, prior acid exposure of C. jejuni cross-protected the bacterium against oxidative stress. Western-blot analysis and real-time qRT-PCR revealed an increased expression of the catalase KatA in acid-stressed C. jejuni relative to unstressed bacteria. The enhanced survival of C. jejuni to oxidative stress was shown to be Fur-dependent through the regulation of katA expression. Electrophoretic mobility shift assay (EMSA) demonstrated that the binding affinity between Fur and katA is reduced under low pH allowing for higher expression of katA and the defense against oxidative stress. Strikingly, the ∆fur mutant exhibited a reduced virulence capacity in both human epithelial cells and G. mellonella infection model as compared to C. jejuni wild-type. Altogether, this is the first study showing that in addition to its role in iron metabolism, Fur is an important regulator of C. jejuni acid response and cross-protection against other stresses. Moreover, our results clearly demonstrate that Fur plays a substantial role in C. jejuni host pathogenesis. Campylobacter jejuni is a prevalent cause of bacterial gastroenteritis in humans worldwide. The mechanism by which C. jejuni survives stomach acidity remains unknown. Herein, we have demonstrated that C. jejuni with a fur deletion was more sensitive to acid than the wild-type strain. Profiling the acid stimulon of the C. jejuni ∆fur mutant allowed us to uncover Fur-regulated genes under acidic conditions. The up-regulation of heat shock genes and the down-regulation of genes involved in flagellar and cell envelope biogenesis in the fur mutant highlight the importance of Fur in Campylobacter acid survival. Interestingly, prior acid exposure of C. jejuni cross-protected the bacterium against oxidative stress. Western-blot analysis and real-time qRT-PCR revealed an increased expression of the catalase KatA in acid-stressed C. jejuni relative to unstressed bacteria. The enhanced survival of C. jejuni to oxidative stress was shown to be Fur-dependent through the regulation of katA expression. Electrophoretic mobility shift assay (EMSA) demonstrated that the binding affinity between Fur and katA is reduced under low pH allowing for higher expression of katA and the defense against oxidative stress. Strikingly, the ∆fur mutant exhibited a reduced virulence capacity in both human epithelial cells and G. mellonella infection model as compared to C. jejuni wild-type. Altogether, this is the first study showing that in addition to its role in iron metabolism, Fur is an important regulator of C. jejuni acid response and cross-protection against other stresses. Moreover, our results clearly demonstrate that Fur plays a substantial role in C. jejuni host pathogenesis.
2016-03-17 | GSE73796 | GEO
Project description:Lipidomic analysis of C. jejuni strains evolved to grow in human breastmilk.
2024-04-24 | MSV000094612 | MassIVE