Project description:In order to study the function of the Campylobacter jejuni Cj0667 gene, a series of experiments were carried out. Two strains were constructed: a Cj0667 knockout strain and a strain with a second copy over-expressing Cj0667 from an fdxA promoter. The transcriptomes of these were all compared to the wild-type strain. The arrays are all from RNA isolated in mid-exponential growth.
Project description:Transcriptional regulation mediates adaptation of pathogens to environmental stimuli and is important for host colonisation. The Campylobacter jejuni genome sequence reveals a surprisingly small set of regulators, mostly of unknown function, suggesting an intricate regulatory network. Interestingly, C. jejuni lacks the homologues of ubiquitous regulators involved in stress response found in many other Gram-negative bacteria. Nonetheless, cj1000 is predicted to code for the sole LysR-type regulator in the C. jejuni genome, and thus may be involved in major adaptation pathways. A cj1000 mutant strain was constructed and found to be attenuated in its ability to colonise 1-day old chicks. Complementation of cj1000 mutation restored the colonisation ability to that of wild type levels. The mutant strain was also outcompeted in a competitive colonisation assay of the piglet intestine. High resolution oxygraphy was carried out for the first time on C. jejuni and revealed a role for Cj1000 in controlling O2 consumption. Furthermore, microarray analysis of the cj1000 mutant revealed both direct and indirect regulatory targets, including genes involved in energy metabolism and oxidative stress defences. These results highlight the importance of Cj1000 regulation in host colonisation and in major physiological pathways.
Project description:Campylobacter jejuni is the leading cause of campylobacteriosis in the developed world. Although most cases are caused by consumption of contaminated meat, a significant proportion is caused by consumption of contaminated water. Some C. jejuni isolates are better than others at surviving in water, which suggests that these strains are better adapted to transmission by water than others. The aim of this study is to investigate this phenomenon further. CFU counts and viability assays showed that strain 81116 survives better than strain 81-176 in a defined freshwater medium at 4°C. Comparative transcriptomic profiling using microarray revealed that these strains respond differently to water. This series presents the transcriptome of strain 81116 in water.
Project description:In order to study the function of the Campylobacter jejuni Cj1103 gene, a series of experiments were carried out. Three strains were constructed: a Cj1103 knockout strain, a strain where the Cj1103 knockout was complemented in trans, and a strain with a second copy over-expressing Cj1103 from an metK promoter. The transcriptomes of these were all compared to the wild-type strain. The arrays are all from RNA isolated in mid-exponential growth from independent biological replicates.
Project description:In order to study the function of the Campylobacter jejuni Cj0138 gene, a series of experiments were carried out. Three strains were constructed: a Cj0138 knockout strain, a strain where the Cj0138 knockout was complemented in trans, and a strain with a second copy over-expressing Cj0138 from an fdxA promoter. The transcriptomes of these were all compared to the wild-type strain. The arrays are all from RNA isolated in mid-exponential growth from independent biological replicates.
Project description:In order to study the function of the Campylobacter jejuni Cj1501 gene, a series of experiments were carried out. Three strains were constructed: a Cj1501 knockout strain, a strain where the Cj1501 knockout was complemented in trans, and a strain with a second copy over-expressing Cj1501 from an fdxA promoter. The transcriptomes of these were all compared to the wild-type strain. The arrays are all from RNA isolated in mid-exponential growth from independent biological replicates.
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 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.