Project description:N-linked glycosylation is an essential virulence determinant in Campylobacter jejuni, the major causative agent of gastroenteritis in the developed world. Glycosylation is encoded by the pgl gene cluster which encodes for the biosynthesis and attachment of a conserved heptasaccharide glycan to proteins in the C. jejuni periplasm. Over 80 membrane-associated proteins have been identified, however the functional role played by glycan attachment is almost completely unknown. We used quantitative proteomics by label-based and targeted strategies to examine glycosylation negative C. jejuni in comparison to wild-type. These technical approaches were considered as ‘discovery’ (label-based) and ‘validation’ data sets in our subsequent analysis. Inclusion of a glycosylation restored strain enabled us to further exploit the proteomics data to exclude non-specific protein abundance changes that could be considered as off-target effects. These data have provided a reference set of changes associated with protein N-glycosylation that could subsequently be tested by phenotypic analysis to determine the role of this modification in Campylobacter biology.
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.
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).
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. 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).