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:Background. The bacterial foodborne pathogen Campylobacter jejuni is a common cause of acute gastroenteritis and is also associated with the postinfectious neuropathies, Guillain-Barré and Miller Fisher syndromes. This study described the use of multilocus sequence typing and DNA microarrays to examine the genetic content of a collection of South African C. jejuni strains, recovered from patients with enteritis, Guillain-Barré or Miller Fisher syndromes. Methodology/Principal Findings. The comparative genomic analysis by using multilocus sequence typing and DNA microarrays demonstrated that the South African strains with Penner heat-stable (HS) serotype HS:41 were clearly distinct from the other South African strains. Further analysis of the DNA microarray data demonstrated that the serotype HS:41 strains from South African GBS and enteritis patients are highly similar in gene content. Interestingly, the South African HS:41 strains were distinct in gene content when compared to serotype HS:41 strains from other geographical locations due to the presence of genomic islands, referred to as Campylobacter jejuni integrated elements. Only the genomic integrated element CJIE1, a Campylobacter Mu-like prophage, was present in the South African HS:41 strains whereas absent in the closely-related HS:41 strains from Mexico. A more distantly-related HS:41 strain from Canada possessed both genomic integrated elements CJIE1 and CJIE2. Conclusion/Significance. These findings demonstrated that these C. jejuni integrated elements may contribute to the differentiation of closely-related C. jejuni strains. In addition, the presence of bacteriophage-related genes in CJIE1 may probably contribute to increasing the genomic diversity of these C. jejuni strains. This comparative genomic analysis of the foodborne pathogen C. jejuni provides fundamental information that potentially could lead to improved methods for analyzing the epidemiology of disease outbreaks and their sources. Keywords: comparative genomic indexing analysis
Project description:We performed microarray CGH analysis of 104 neuropathogenic and enteritis only stains of C. jejuni. Keywords: Individual hybridizations, CGH
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.
Project description:Campylobacter jejuni is a common cause of diarrheal disease worldwide. Human infection typically occurs through the ingestion of contaminated poultry products. We previously demonstrated that an attenuated Escherichia coli live vaccine strain expressing the C. jejuni N-glycan on its surface reduces the Campylobacter load in more than 50% of vaccinated leghorn and broiler birds to undetectable levels (responder birds), whereas the remainder of the animals were still colonized (non-responders). To understand the underlying mechanism, we conducted 3 larger scale vaccination and challenge studies using 135 broiler birds and found a similar responder/non responder effect. The submitted data were used for a genome-wide association study of the chicken responses to glycoconjugate vaccination against Campylobacter jejuni.
Project description:Background: The food-borne pathogen Campylobacter is one of the most important zoonotic pathogens. Compared to other zoonotic bacteria, Campylobacter species are quite susceptible to environmental or technological stressors. This might be due to the lack of many stress response mechanisms described in other bacteria. Nevertheless, Campylobacter is able to survive in the environment and food products. Although some aspects of the heat stress response in Campylobacter (C.) jejuni are already known, information about the heat stress response in the related species C. coli and C. lari are still unknown. Results: The stress response to elevated temperatures (46°C) was investigated by survival assays and whole transcriptome analyses for the strain C. jejuni NCTC11168, C. coli RM2228 and C. lari RM2100. While C. jejuni showed highest thermotolerance followed by C. lari and C. coli, none of the strains survived at this temperature for more than 24 hours. Transcriptomic analyses revealed that only 3 % of the genes in C. jejuni and approx. 20 % of the genes of C. coli and C. lari were differentially expressed after heat stress, respectively. The transcriptomic profiles showed enhanced gene expression of several chaperones like dnaK, groES, groEL and clpB in all strains, but differences in the gene expression of transcriptional regulators like hspR, perR as well as for genes involved in metabolic pathways, translation processes and membrane components. However, the function of many of the differentially expressed gene is unknown so far. Conclusion: We could demonstrate differences in the ability to survive at elevated temperatures for C. jejuni, C. coli and C. lari and showed for the first time transcriptomic analyses of the heat stress response of C. coli and C. lari. Our data suggest that the heat stress response of C. coli and C. lari are more similar to each other compared to C. jejuni, even though on genetic level a higher homology exists between C. jejuni and C. coli. This indicates that stress response mechanisms described for C. jejuni might be unique for this species and not necessarily transferable to other Campylobacter species.
Project description:Background: The food-borne pathogen Campylobacter is one of the most important zoonotic pathogens. Compared to other zoonotic bacteria, Campylobacter species are quite susceptible to environmental or technological stressors. This might be due to the lack of many stress response mechanisms described in other bacteria. Nevertheless, Campylobacter is able to survive in the environment and food products. Although some aspects of the heat stress response in Campylobacter (C.) jejuni are already known, information about the heat stress response in the related species C. coli and C. lari are still unknown. Results: The stress response to elevated temperatures (46°C) was investigated by survival assays and whole transcriptome analyses for the strain C. jejuni NCTC11168, C. coli RM2228 and C. lari RM2100. While C. jejuni showed highest thermotolerance followed by C. lari and C. coli, none of the strains survived at this temperature for more than 24 hours. Transcriptomic analyses revealed that only 3 % of the genes in C. jejuni and approx. 20 % of the genes of C. coli and C. lari were differentially expressed after heat stress, respectively. The transcriptomic profiles showed enhanced gene expression of several chaperones like dnaK, groES, groEL and clpB in all strains, but differences in the gene expression of transcriptional regulators like hspR, perR as well as for genes involved in metabolic pathways, translation processes and membrane components. However, the function of many of the differentially expressed gene is unknown so far. Conclusion: We could demonstrate differences in the ability to survive at elevated temperatures for C. jejuni, C. coli and C. lari and showed for the first time transcriptomic analyses of the heat stress response of C. coli and C. lari. Our data suggest that the heat stress response of C. coli and C. lari are more similar to each other compared to C. jejuni, even though on genetic level a higher homology exists between C. jejuni and C. coli. This indicates that stress response mechanisms described for C. jejuni might be unique for this species and not necessarily transferable to other Campylobacter species.
Project description:Campylobacter jejuni is a highly prevalent food-borne pathogen that causes diarrhoeal disease in humans. A natural zoonotic, it must overcome significant stresses both in vivo and during transmission despite the absence of several traditional stress response genes. Its ability to interact with and invade human intestinal epithelial cells closely correlates with virulence. A C. jejuni microarray-based screen revealed that several known virulence genes and several uncharacterized genes, including spoT, were rapidly upregulated during infection of human epithelial cells. spoT and its homologue relA have been shown in other bacteria to regulate the stringent response, an important stress response that to date had not been demonstrated for C. jejuni. We have found that C. jejuni mounts a stringent response that is regulated by spoT. Detailed analyses of a C. jejuni delta spoT mutant revealed that the stringent response is required for several specific stress, transmission and antibiotic resistance-related phenotypes. These include stationary phase survival, growth and survival under low CO2/high O2 conditions, and rifampicin resistance. A secondary suppressor strain that specifically rescues the low CO2 growth defect of the delta spoT mutant was also isolated. The stringent response additionally proved to be required for the virulence-related phenotypes of adherence, invasion, and intracellular survival in two human epithelial cell culture models of infection; spoT is the first C. jejuni gene shown to participate in longer term survival in epithelial cells. Comparing wt to the delta spoT mutant also revealed a strong correlation between gene expression profiles and phenotype differences observed. Together, these data demonstrate a critical role for the C. jejuni stringent response in multiple aspects of C. jejuni biology and pathogenesis.