AI-2 does not function as a quorum sensing molecule in Campylobacter jejuni during exponential growth in vitro
Ontology highlight
ABSTRACT:
ORGANISM(S): Campylobacter jejuni
SUBMITTER: Kathryn Holmes
PROVIDER: E-GEOD-18455 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Transcriptional profiling of Campylobacter jejuni NCTC 11168 wild type versus LuxS01 mutant strain grown in a minimal culture medium (MEM- α ) versus complex culture medium (MHB). Two-condition experiment, the parent versus the mutant 11168 strains were grown in 2 types of culture medium for comparison. Control microarrays included comparing wild type vs wild type in the same culture medium. 4 biological replicates for each test microarray and 2 biological replicates for each control microarray, independently grown and harvested.
2010-06-21 | E-GEOD-18451 | biostudies-arrayexpress
Project description:Transcriptional profiling of Campylobacter jejuni NCTC 11168 wild type and LuxS01 mutant strains comparing the effects of exogenously added in vitro-produced autoinducer 2 (AI-2) versus a control buffer to both strains. Two-condition experiment, addition of exogenous AI-2 to both the parent and mutant 11168 strains. Control microarrays included comparing 11168 with AI-2 free buffer vs 11168 with AI-2-free buffer and mutant with AI-2 free buffer versus mutant with AI-2 free buffer used for analyses. 3 biological replicates for each, independently grown and harvested.
2010-06-21 | E-GEOD-18427 | biostudies-arrayexpress
Project description:RNAtag-Seq were used to investigate the transcriptomic landscape of C. jejuni under 22 growth and stress conditions, with 3 replicates from each condition. 5 extra repeats were created to replaces low-quality samples.
2022-05-27 | E-MTAB-11309 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2012-12-31 | E-GEOD-35137 | biostudies-arrayexpress
Project description:The transcription start sites of the Campylobacter jejuni genome was identified by Cappable-seq, which captures primary transcripts by capping the 5´ triphosphorylated end
2022-05-27 | E-MTAB-11308 | biostudies-arrayexpress
Project description:Background: During gut colonization, the enteric pathogen C. jejuni has to surmount the toxic effects of reactive oxygen species produced by its own metabolism, by the host immune system and by the intestinal microflora. Elucidation of C. jejuni oxidative stress defense mechanisms is critical for understanding Campylobacter pathophysiology. Results: The mechanisms of oxidative stress defenses in Campylobacter jejuni were characterized by transcriptional profiling, genes mutagenesis, and phenotypic analysis. The transcriptome changes, in response to H2O2, cumene hydroperoxide, or menadione exposure, were found to be oxidant specific and revealed the differential expression of genes belonging to a variety of biological pathways, from the classical oxidative stress defense systems, to the heat shock response, DNA repair and metabolism, fatty acid and capsule biosynthesis, and multidrug efflux pumps. To define the peroxide sensing regulator PerR, an isogenic mutant was constructed and its transcriptome profile compared to the wild-type strain. Sixty-six genes were found to belong to the PerR regulon. PerR appear to regulate gene expression both dependently and independently of the presence of iron and/or H2O2. The perR mutant was affected in its motility and attenuated in the chick colonization model. Mutagenic and phenotypic studies of the superoxide disumutase SodB, the alkyl-hydroxyperoxidase AhpC, and the catalase KatA, revealed their role in oxidative stress defenses and chick gut colonization. Conclusion: This study reveals the interplay between PerR, the iron metabolism and the oxidative stress defenses and highlights their role in the colonization and/or survival of C. jejuni in the chick cecum. Keywords: Transcriptional response to 3 oxidants (H2O2, menadione and cumene hydroperoxide) and characterization of the perR regulon (comparison of the transciptomes from the wild-type and perR mutant). To investigate the transcriptional responses of C. jejuni to oxidant exposure, hydrogen peroxide (H2O2), cumene hydroperoxide (CHP), or menadione sodium bisulfite (MND) was added to the 50 ml broth at a final concentration of 1 mM. The same amount of water or DMSO was added to the bacterial culture that served as reference samples for the transcriptional profile study in response to H2O2, MND or CHP. Furthermore, to investigate the transcriptional response of C. jejuni to H2O2 exposure in the presence of excess iron, ferrous sulfate was added to the bacterial culture at a final concentration of 40 µM, 15 min prior to H2O2 exposure. Ten minutes after the addition of the oxidant, total RNA was extracted and processed for microarray hybridization. To identify the PerR regulon, the wild-type strain C. jejuni NCTC 11168 and the perR mutant were grown in 500 ml flasks containing 250 ml of MEMα medium. At mid-log phase, 50 ml of the cultures were transferred to 100 ml flasks and ferrous sulfate and/or H2O2 were added . Ten minutes following the addition of H2O2 the cells were collected and the total RNA extracted.
2010-09-07 | E-GEOD-13126 | biostudies-arrayexpress
Project description:Purpose: Study hypoxia induced changes in genome-wide H3K27me3 occupancy Methods: Using the MCF7 breast epithelial adenocarcinoma cell line as a model, we studied epigenomic reprogramming as a function of fluctuating oxygen tension. To this end, we combined chromatin-immunoprecipitation and deep-sequencing analysis to identify H3K27me3-marks in MCF7 cells subjected to changes in oxygenation (i.e. acute hypoxia, chronic hypoxia). Results: H3K27me3-marks showed a rapid global increase at specific sites throughout the genome under hypoxia, both genic and inter-genic. Conclusions: Our data show that oxygen availability dynamically regulates the epigenetic state of the genome. Genome-wide H3K27me3-mark profiles were generated by combining ChIP analysis with deep sequencing using Illumina GAIIx.
2014-09-26 | E-GEOD-61740 | biostudies-arrayexpress
Project description:Campylobacter jejuni is one of the leading causes of bacterial diarrhea worldwide and the most common antecedent in peripheral neuropathies such as Guillain Barré and Miller Fisher syndromes (Blaser et al., 2000). Despite the medical and socioeconomic importance of C. jejuni, the proportion of human disease caused by different sources of infection remains unclear. Indeed, this issue has hindered effective control strategies against reducing C. jejuni levels from the food chain. Up to date, a vast number of phenotypic and genotypic typing systems and a large number of databases have been developed in order to determine the different Campylobacter infection sources. However, traditional methods are unable to discriminate strains from different sources that are responsible for causing disease in humans. Interestingly, DNA microarrays represent a technological alternative to compare entire genomes, allowing the identification of all the genes present or absent in a particular strain by comparison with the genome of the reference strain present in the microarray. Previous comparative genomic hybridazation studies of C. jejuni using DNA microarrays have focused on the genetic variability in C. jejuni (Dorrell et al., 2001), which suggest that this organism has high levels of genetic diversity and low levels of genetic plasticity (Taboada et al., 2004). On that account, the aim of this study was based on a comparison by CGH (Comparative Genomic Hybridization) using DNA microarrays for determining the degree of genomic variability of C. jejuni strains from different geographical areas and sources of isolation. This system enabled us to identify possible genes that could be used as genetic markers predictive of infection source. Furthermore, CGH data provide additional information that could be useful for the formulation of new hypotheses about C. jejuni genome evolution, virulence, pathogenicity, and host specificity.
2015-06-15 | E-MTAB-3550 | biostudies-arrayexpress
Project description:Transcriptomic analysis of C. jejuni HPC5 grown in anaerobic jar supplemented with air mix and in Modular Atmospheric Controlled System (MAC). C. jejuni HPC5 is a Campylobacter strain isolated from broiler chickens. Majority of the Campylobacter strains are cultured in an atmosphere containing 5-10% (v/v) oxygen or 5% hydrogen and 5-10% (v/v) carbon dioxide and the rest with nitrogen. To set up a jar (3.5L, Oxoid) to the required microaerophilic conditions, a vacuum is created to -22 psi and then air mixture of 85% v/v nitrogen, 10% v/v carbon dioxide and 5% v/v hydrogen (Air Products, Crewe, UK) is introduced into the jar. This resulted in a microaerobic atmosphere containing approximately 5.6% oxygen, 3.6% hydrogen, 7.3% carbon dioxide and 83% nitrogen. The Modular Atmospheric Controlled System (MAC; Don Whitely Scientific) is an anaerobic chamber where air mixture of 85% nitrogen, 10% carbon dioxide and 5% oxygen is used for growing Campylobacter. Differences in growth pattern were observed when Campylobacters were grown in it and transcriptomic analysis was done to prove the difference in the regulation of genes in the two conditions. 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 (Fisher, UK). The labelled cDNAs were mixed together and this acted as the control. C. jejuni HPC5 was grown both in the Jar and in the MAC and their cDNAs were labelled independently with AF645 (Fisher, UK). Hybridisations were done between C. jejuni HPC5 grown in jar and in MAC in triplicates. The supplementary file (linked at the foot of this record) represents the averaged normalised values for each experimental condition (3replicates/experimental condition).
2011-04-01 | E-GEOD-17801 | biostudies-arrayexpress
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. Batch cultures of Campylobacter jejuni NCTC 11168 were grown in 50 ml volumes of Brucella broth in 70cm tissue culture flasks. Microaerophilic conditions were generated using a MACS-VA500 microaerophilic work station (5% Oxygen, 10% Carbon dioxide, 85% Nitrogen) from Don Whitley Scientific, Ltd which also maintained the growth temperature at 37 M-BM-:C. RNA was extracted from C. jejuni cultures grown to an OD600 of approximately 0.4. Briefly, 0.1 volume of 5% phenol in ethanol was mixed with the broth culture, and after centrifugation RNA was isolated with Tri Reagent (Sigma) and chloroform. RNA was further purified using the RNeasy kit (Qiagen) according to the manufacturerM-bM-^@M-^Ys instructions. The RNA was treated with Turbo DNA-free (Ambion) to remove any residual DNA according to the manufacturerM-bM-^@M-^Ys instructions. RNA concentration was determined using the Nanodrop Spectrophotometer NS-1000 (Thermo Scientific). RNA preparations of each sample type were labelled and hybridized to custom-designed Agilent microarrays. Equal quantities of RNA from test and control cultures were labelled by using nucleotide homologues of dUTP containing either Cy3 or Cy5 fluorescent dye (Perkin Elmer). For each microarray slide, the test strain was labelled with Cy3-dUTP, while the wild-type sample was labelled with Cy5-dUTP. RNA (15 M-BM-5g) was primed with 5 M-BM-5g pd(N)6 random hexamers (Amersham Biosciences). The Affinity Script kit (GE Healthcare) was used to produce cDNA, and hybridized (Agilent Hi-RPM Gene Expression Hybridization Kit) to the microarray slide according to the manufacturerM-bM-^@M-^Ys instructions. Microarrays were scanned at 5 M-BM-5m using an Axon 4000A scanner, and images were acquired using GenePix Pro 3.0 software (Axon). Related analysis reference: Holmes K., Mulholland F., Pearson B. M., Pin C., McNicholl-Kennedy J., Ketley J. M., Wells J. M. (2005) Campylobacter jejuni gene expression in response to iron limitation and the role of Fur Microbiology-SGM 151 243-257 (PMID 15632442).
2012-12-31 | E-GEOD-35120 | biostudies-arrayexpress