Project description:C. jejuni HPC5 is a Campylobacter strain isolated from chickens. Following bacteriophage CP34 treatment on chickens colonised by C. jejuni HPC5, a series of CP34 insensitive strains like C. jejuni HPC5 R14 and C. jejuni HPC5 R20 were obtained which compromised their ability to colonise chickens. Reintroduction of C. jejuni HPC5 R14 and R20 in to chickens led to reversion of these strains and the MRPs of the revertant strains fell in to different classes termed C. jejuni HPC5 R14A, R14B, R20A, R20B and R20C and these strained were tested positive for colonisation proficient and bacteriophage sensitive.
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.
Project description:To investigate the interaction of intra-amoebal C. jejuni with the transient host A. castellanii. We then performed gene expression profiling analysis using data obtained from RNA-seq of control and intra-amoebal C. jejuni.
Project description:C. jejuni HPC5 is a Campylobacter strain isolated from chickens. Following bacteriophage CP34 treatment on chickens colonised by C. jejuni HPC5, a series of CP34 insensitive strains like C. jejuni HPC5 R14 and C. jejuni HPC5 R20 were obtained which compromised their ability to colonise chickens. Reintroduction of C. jejuni HPC5 R14 and R20 in to chickens led to reversion of these strains and the MRPs of the revertant strains fell in to different classes termed C. jejuni HPC5 R14A, R14B, R20A, R20B and R20C and these strained were tested positive for colonisation proficient and bacteriophage sensitive. There are three biological replicates for each experiment. Seven independent cDNA preps of C. jejuni HPC5 were prepared and they were labelled independently using AF555. The labelled cDNAs were mixed together and this acted as the control. Each daughter strains were considered as sample and they were labelled with AF645. Hybridisations were done between C. jejuni HPC5 and C. jejuni HPC5 as one of the sample and each of the daughter strains in triplicates. The supplementary files (linked at the foot of this record) contain the summary of the replicate data of the corresponding strain (3 replicates/strain) which have been averaged.
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. Microarray data was collected from three independent biological replicates and 9 technical replicates for each biological replicate.
Project description:Transcriptional profile of C. jejuni NCTC11168 while growing in MEM medium containing L-fucose. We hypothesize that certain C. jejuni strains, containing A certain genomic island, have acquired the ability to metabolize fucose. This study demonstrates the transcriptional profile C. jejuni growth while utilizing fucose.
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 a widespread pathogen responsible for most of the food-borne gastrointestinal diseases in Europe. For pathogen control in the food industry, the use of natural antimicrobial molecules is a promising strategy to avoid antibiotic treatments. Isothiocyanates are natural antimicrobial compounds which also display anti-cancer activity. Several studies described the chemoprotective effect of isothiocyanates on eukaryotic cells, but the antimicrobial mechanism is still poorly understood. We investigated the early cellular response of C. jejuni to benzylisothiocyanate (BITC) by both transcriptomic and physiological (respirometry, ATP content measurements and isolations of aggregated proteins).
Project description:Bacteria have evolved different mechanisms to catabolize carbon sources from a mixture of nutrients. They first consume their preferred carbon source, before others are used. Regulatory mechanisms adapt the metabolism accordingly to maximize growth and to outcompete other organisms. The human pathogen Campylobacter jejuni is an asaccharolytic Gram-negative bacterium that catabolizes amino acids and organic acids for growth. It prefers serine and aspartate as carbon sources, however it lacks all regulators known to be involved in regulating carbon source utilization in other organisms. In which manner C. jejuni adapts its metabolism towards the presence or absence of preferred carbon sources is unknown. In this study, we show with transcriptomic analysis and enzyme assays how C. jejuni adapts its metabolism in response to its preferred carbon source serine. In the presence of serine as well as lactate and pyruvate C. jejuni represses the utilization of other carbon sources, by repressing the expression of a number of central metabolic enzymes. The regulatory proteins RacR, Cj1000 and CsrA play a role in the regulation of these metabolic enzymes. This metabolism dependent transcriptional repression correlates with an accumulation of intracellular succinate. Hence, we propose a demand-based catabolite repression mechanism in C. jejuni, which depends on the intracellular succinate level.