CmeR functions as global regulator in Campylobacter jejuni
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ABSTRACT:
ORGANISM(S): Campylobacter jejuni
PROVIDER: GSE5412 | GEO | 2008/02/27
SECONDARY ACCESSION(S): PRJNA96227
REPOSITORIES: GEO
Similar Datasets
Project description:Campylobacter, a major foodborne pathogen, is increasingly resistant to macrolide antibibotics. Previous findings suggested that development of macrolide resistance in Campylobacter requires a multi-step process, but the molecular mechanisms involved in the process are not known. In our study, erythromycin-resistant C. jejuni mutant (R) was selected in vitro by stepwise exposure of C. jejuni NCTC11168(S) to increasing concentrations of erythromycin.The resistant were subjected to microarray and the the global transcriptional profile was analyzed. In this series, DNA microarray was used to compare the gene expression profiles of the macrolide-resistant strain with its parent wild-type strain NCTC11168. A large number of gene showed significant changes in R. The up-regulated genes in the resistant strains are involved in miscellaneous periplasmic proteins, efflux protein and putative aminotransferase, while the majority of the down-regulated genes are involved in electron transport, lipoprotein, heat shock protein and unknown function proteins. The over-expression of efflux pump and periplasmic protein was involved in the development of resistance to macrolide in C. jejuni. An eight chip study using total RNA recovered from four separate resistant-type cultures of Erythrocin-resistant Campylobacter jejuni NCTC111168 (R) and four separate cultures of Campylobacter jejuni NCTC111168 (S). Each chip measures the expression level of 1634 genes from Campylobacter jejuni NCTC11168.
2013-08-13 | E-GEOD-49257 | biostudies-arrayexpress
Project description:Objectives: The aim of the study was to characterize (-)-α-Pinene, which is one of the chemical constituents of Alpinia katsumadai seed essential oil responsible for its resistance modulatory activity in Campylobacter jejuni. Methods: Broth microdilution method was used to evaluate the antimicrobial and resistance modulatory potential of (-)-α-Pinene and ethidium bromide accumulation assay to determine its efflux-inhibitory activity in subinhibitory concentration. The target efflux system was identified using knock-out mutants in several efflux related genes. Furthermore, the influence of subinhibitory concentration of (-)-α-Pinene on C. jejuni NCTC 11168 was investigated using microarray technology in order to elucidate the adaptive mechanism of bacteria to treatment with this phytochemical. Knock-out mutants of key adaptation genes were constructed and their role in adaptation to several stress factors, including (-)-α-Pinene, different osmolites and pH, was investigated using Biolog phenotypical microarrays and CFU counts. Results: (-)-α-Pinene was confirmed as highly efficient Campylobacter jejuni resistance modulator, due to its efflux inhibitory activity, which was significantly higher compared to reference inhibitors CCCP and reserpine. The CmeABC along with newly characterized CmeI (Cj1687) was confirmed as its main target efflux system. The transcriptional analysis indicated that the heat shock regulators HspR and HrcA are the main transcription regulators involved in adaptation to (-)-α-Pinene treatment. Conclusions: (-)-α-Pinene is a novel CmeABC and CmeI efflux inhibitor, which evokes the heat shock response in Campylobacter jejuni.
2015-11-19 | GSE59879 | GEO
Project description:In eukaryotes glycosylation plays a role in proteome stability, protein quality control and modulating protein function, however, similar studies in bacteria are lacking. Here, we investigate the role of general protein glycosylation systems in bacteria using the enteropathogen Campylobacter jejuni as a well-defined example. By using a quantitative proteomics strategy, we were able to monitor changes in the C. jejuni proteome when glycosylation is disrupted. We demonstrate that in C. jejuni, N-glycosylation is essential to maintain proteome stability and protein quality control. These findings guided us to investigate the role of N-glycosylation in modulating bacterial cellular activities. In glycosylation deficient C. jejuni, the multidrug efflux pump and electron transport pathways were significantly impaired. In vivo, we demonstrate that fully glycosylation deficient C. jejuni were unable to colonise its natural avian host. These results provide the first evidence of a link between proteome stability and complex functions via a bacterial general glycosylation system.
2021-09-08 | PXD011452 | Pride
Project description:Campylobacter, a major foodborne pathogen, is increasingly resistant to macrolide antibibotics. Previous findings suggested that development of macrolide resistance in Campylobacter requires a multi-step process, but the molecular mechanisms involved in the process are not known. In our study, erythromycin-resistant C. jejuni mutant (R) was selected in vitro by stepwise exposure of C. jejuni NCTC11168(S) to increasing concentrations of erythromycin.The resistant were subjected to microarray and the the global transcriptional profile was analyzed. In this series, DNA microarray was used to compare the gene expression profiles of the macrolide-resistant strain with its parent wild-type strain NCTC11168. A large number of gene showed significant changes in R. The up-regulated genes in the resistant strains are involved in miscellaneous periplasmic proteins, efflux protein and putative aminotransferase, while the majority of the down-regulated genes are involved in electron transport, lipoprotein, heat shock protein and unknown function proteins. The over-expression of efflux pump and periplasmic protein was involved in the development of resistance to macrolide in C. jejuni.
2013-08-13 | GSE49257 | GEO
Project description:Objectives: The aim of the study was to characterize (-)-α-Pinene, which is one of the chemical constituents of Alpinia katsumadai seed essential oil responsible for its resistance modulatory activity in Campylobacter jejuni. Methods: Broth microdilution method was used to evaluate the antimicrobial and resistance modulatory potential of (-)-α-Pinene and ethidium bromide accumulation assay to determine its efflux-inhibitory activity in subinhibitory concentration. The target efflux system was identified using knock-out mutants in several efflux related genes. Furthermore, the influence of subinhibitory concentration of (-)-α-Pinene on C. jejuni NCTC 11168 was investigated using microarray technology in order to elucidate the adaptive mechanism of bacteria to treatment with this phytochemical. Knock-out mutants of key adaptation genes were constructed and their role in adaptation to several stress factors, including (-)-α-Pinene, different osmolites and pH, was investigated using Biolog phenotypical microarrays and CFU counts. Results: (-)-α-Pinene was confirmed as highly efficient Campylobacter jejuni resistance modulator, due to its efflux inhibitory activity, which was significantly higher compared to reference inhibitors CCCP and reserpine. The CmeABC along with newly characterized CmeI (Cj1687) was confirmed as its main target efflux system. The transcriptional analysis indicated that the heat shock regulators HspR and HrcA are the main transcription regulators involved in adaptation to (-)-α-Pinene treatment. Conclusions: (-)-α-Pinene is a novel CmeABC and CmeI efflux inhibitor, which evokes the heat shock response in Campylobacter jejuni. Influence of (-)-α-Pinene on gene expression in C. jejuni NCTC 11168 was determined by expressional analysis and qRT-PCR. Exponential phase culture was adjusted to OD600=0.2 in MHB using spectrophotometer (Smart Spec, Bio-Rad, Hercules, CA, USA). Five ml of culture was treated with 62.5 mg/L of (-)-alpha-pinene dissolved in DMSO. Only DMSO (0.048 %) was added to untreated samples. Cultures were treated for 2 h, incubated microaerobically shaking (160 rpm) at 42°C. Experiments were carried out in 4 biological replicates. RNA Protect Bacteria reagent (Qiagen, Maryland, USA) was added to the culture and total RNA was isolated using RNeasy mini kit (Qiagen) and treated with Ambion® Turbo DNA-freeTM kit (Invitrogen, USA). Microarrays with 4751 probes targeting 1756 genes specific for Campylobacter jejuni subsp. jejuni NCTC 11168 (Mycroarray, Biodiscovery-LLC, MI, USA) were used for gene expression analysis. The cDNA was synthesized with random hexamers, SuperScriptTM III Reverse Transcriptase and amynoallyl dUTP (all supplied by Invitrogen, USA) and labeled with monofunctional NHS-ester dye Amersham C3 or Cy5 (GE Healthcare, Buckinghamshire, UK). Concentration of cDNA and labeling efficiency was determined spectrophotometrically with NanoDrop 1000. Four biological replicates were hybridized to four microarrays according to manufacturerâs protocol, incubated for 24 hours at 42â°C and scanned at 532-nm (Cy3) and 635-nm (Cy5) wavelengths using GenePix 4100A (Molecular Devices, Sunnyvale, CA) following the manufacturer's protocol. Fluorescence intensities of each spot were extracted using GenePix Pro 7.0 (Molecular Devices).
2015-11-19 | E-GEOD-59879 | biostudies-arrayexpress
Project description:Campylobacter, a major foodborne pathogen, is increasingly resistant to macrolide antibibotics. Previous findings suggeted that development of macrolide resistance in campylobacter requires a multi-step process, but the molecular mechanisms involved in the process are not known. In our study, multiple series of macrolide-resistant C. jejuni mutants were selected in vitro by stepwise exposure of C. jejuni NCTC11168 to increasing concentrations of erythromycin and tylosin. A set of the selected resistance were subjected to microarray and the the global transcriptional profile was analyzed. In this sery, DNA microarray was used to compare the gene expression profiles of macrolide resistant strains (68E1, 68E8 and 68E64) with its parent wild-type strain NCTC11168. The assay identified a small number of genes that showed significant changes (q-value<0.1) in expression in the low-level macrolide resistant strain 68E1, while a large number of gene showing significant changes in intermedia-level resistant stran 68E8 and high-level resistant strain 68 E64. The up-regulated genes in the resistant strains are involved in miscellaneous periplasmic proteins, efflux protienand putative aminotransferase, while the majority of the down-regulated genes are involved in electron transport,lipoprotein, heat shock protein and unknown function proteins. These findings suggest that there is not much change in low-level macrolide resistant C. jejuni strain. The over-expression of efflux pump and periplasmic protein was involved in the development of resistance to macrolide in C. jejuni. Keywords: macrolide resistant C. jejuni selected from NCTC 11168 step-wise selection. The design utilized an available two color microarray slide for the entire transcriptome of Campylobacter jejuni. Four hybridizations were performed each with independently extracted samples of either macrolide susceptible C. jejuni NCTC11168 cDNA samples or macrolide resistant C.jejuni cDNA samples. A dye swap was utilized to help minimize dye dependent bias. Thus, there were four biological replicates of each sample.
2010-12-28 | E-GEOD-17881 | biostudies-arrayexpress
Project description:Campylobacter, a major foodborne pathogen, is increasingly resistant to macrolide antibibotics. Previous findings suggeted that development of macrolide resistance in campylobacter requires a multi-step process, but the molecular mechanisms involved in the process are not known. In our study, multiple series of macrolide-resistant C. jejuni mutants were selected in vitro by stepwise exposure of C. jejuni NCTC11168 to increasing concentrations of erythromycin and tylosin. A set of the selected resistance were subjected to microarray and the the global transcriptional profile was analyzed. In this sery, DNA microarray was used to compare the gene expression profiles of macrolide resistant strains (68E1, 68E8 and 68E64) with its parent wild-type strain NCTC11168. The assay identified a small number of genes that showed significant changes (q-value<0.1) in expression in the low-level macrolide resistant strain 68E1, while a large number of gene showing significant changes in intermedia-level resistant stran 68E8 and high-level resistant strain 68 E64. The up-regulated genes in the resistant strains are involved in miscellaneous periplasmic proteins, efflux protienand putative aminotransferase, while the majority of the down-regulated genes are involved in electron transport,lipoprotein, heat shock protein and unknown function proteins. These findings suggest that there is not much change in low-level macrolide resistant C. jejuni strain. The over-expression of efflux pump and periplasmic protein was involved in the development of resistance to macrolide in C. jejuni. Keywords: macrolide resistant C. jejuni selected from NCTC 11168 step-wise selection.
2010-12-28 | GSE17881 | GEO
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. Microarray data was collected from three independent biological replicates and 3-9 technical replicates for each biological replicate.
2013-07-03 | E-GEOD-43792 | biostudies-arrayexpress
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.
2019-01-11 | PXD011646 | Pride
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.
2013-07-03 | GSE43792 | GEO