• Investigating the expression of some genes involved in the survival of Campylobacter jejuni in gastric acid: A bioinformatics exploration
  • Mahlagha Cheraghi,1 Hossein Sahragard,2 Nastaran Asghari Moghaddam,3,* Bita Bakhshi,4
    1. Department of Biology, Central Tehran Branch, Islamic Azad University, Tehran, Iran
    2. Department of Biology, Central Tehran Branch, Islamic Azad University, Tehran, Iran
    4. Department of Bacteriology, Tarbiat Modares University, Tehran, Iran


  • Introduction: Campylobacter jejuni is a bacterial pathogen that causes gastroenteritis in humans. The ability to survive stomach acidity is a fundamental requirement for C. jejuni to colonize the host and cause disease. Infection with C. jejuni, which causes diarrhea, is one of the most common causes of Guillain-BarrĂ© Syndrome (GBS) is a rare but serious autoimmune disorder that affects the peripheral nervous system. C. jejuni modulates gene expression in response to acid shock in vitro and in vivo, and this response is important for its survival in the stomach. The acid adaptive tolerance response in C. jejuni permits increased survival at lethal pH values, and further research is needed to better understand the transcriptional response of C. jejuni to acidic conditions and its role in the pathogenesis of this bacterium. The acid adaptive tolerance response in C. jejuni permits increased survival at lethal pH values, and further research is needed to better understand the expression of genes in transcriptional response of C. jejuni to acidic conditions and its role in the pathogenesis of this bacterium.
  • Methods: By utilizing the GSE73793 microarray dataset, we employed a combination of GEO2R online tools and R software to extract and analyze the data. Genes exhibiting significant differential expression, determined by parameters P<0.05 and LogFC>|1|, were identified. Subsequently, we isolated the expression profiles of these relevant genes, focusing on those exhibiting increased expression. To gain further insights, we utilized the STRING database to predict protein networks associated with these genes. The resulting network was visualized using the Gephi software.
  • Results: Through careful analysis, we discovered a collection of genes (rplB, rpoA, rplE, tuf) that exhibited notable changes in expression, indicating their potential involvement in the survival of C. jejuni in gastric acid conditions.The (rplB) gene was found to be an one of the primary rNA binding proteins that makes several contacts with the 16S rRNA in the 70S ribosome.The (rpoA) gene, was found to DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. (rplE) is one of the proteins that binds and probably mediates the attachment of the 5S RNA into the large ribosomal subunit, where it forms part of the central protuberance. In the 70S ribosome it contacts protein S13 of the 30S subunit (bridge B1b), connecting the 2 subunits; this bridge is implicated in subunit movement. At the end (tuf) gene is DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. These findings suggest that these genes play important roles in the virulence of C. jejuni and could be potential targets for the development of interventions to prevent and treat infections.
  • Conclusion: Altogether, this study uncovers the transcriptional profile of C. jejuni in response to acidic conditions as those encountered in the stomach and contributes to a better understanding of the genetic response of C. jejuni to acidic conditions, paving the way for potential therapeutic interventions and control measures to mitigate the impact of this pathogen on human health. In addition, our results demonstrate that acid stress jump-starts C. jejuni for efficient gut colonization and host pathogenesis.
  • Keywords: Campylobacter jejuni, gastric acid, Gene expression, bioinformatics analysis, R software