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:Cj0440c, a putative transcriptional regulator, was over-expressed in the high-level erythromycin-resistant (Eryr) Campylobacter jejuni strains. To determine the role of Cj0440c on the development and fitness of erythromycin resistance in C. jejuni, we knocked out Cj0440c in Eryr strain (R) to obtain the Cj0440c mutants (RM). Then we compared the transcriptome of the Cj0440c mutant with that of the parent strain using DNA microarray. These comparisons identified 9 genes that showed a M-bM-^IM-%2-fold change in expression in RM. The differentially expressed genes in RM are related to flagellar biosynthesis and unknown functions. What's more, katA, encoding catalase, down-regulated in RM. Cj0440c may progress flagellar genes expression, help to escape drug pressure and disseminate and colonize smoothly, and Cj0440c in Eryr Campylobacter may protect bacteria from harmful oxygen stress from the host immune system, other microorganism in host intestinal and its own products. These findings indicate that Cj0440c is essential for the fitness (growth) of resistant C. jejuni by controlling the expression of several genes involved in flagellar assembly and catalase, enhancing cell motility for colonization and invasion under the pressure of drug. This study widened our understanding on the molecular mechanism of resistance and provides scientific reference for drug research and application. An eight-chip study using total RNA recoverd from four separate resistant-type cultures of Erythrocin-resistant Campylobacter jejuni NCTC 111168 (R) and four separate cultures of a mutant strain, erythrocin-resistant Campylobacter jejuni NCTC 11168 delta- Cj0440c (RM), in which Cj0440c is deleted. Each chip measures the expression level of 1634 genes from Campylobacter jejuni NCTC 11168.
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: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: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: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: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.