Ontology highlight
ABSTRACT:
PROVIDER: PRJNA503632 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The human intestinal microbiota associated with rats produces in vivo a soluble(s) factor(s) that down-regulates the expression of genes encoding for the Shiga toxin II in E. coli O157:H7. The Shiga toxin II is one of the major virulence factors of E. coli enterohemorragic leading to the deadly hemolitic and uremic syndrome. Investigation of the effect of the human intestinal microbiota on the whole transcriptome of EHEC O157:H7 is of major importance to increase our understanding of the pathogen transcriptomic adaptation in response to the human microbiota. We analysed by microarray hybridization the gene expression pattern of EHEC O157:H7 grown in the caecal content of germ-free rats or rats associated with the human microbiota of a healthy human subject. By doing so, we increased our understanding of the regulatory activities of the human gut microbiota on E. coli O157:H7
2013-09-10 | GSE37095 | GEO
Project description:Transcriptomes of 24 clinical strains of E. coli O157:H7 that differ phylogenetically and by Shiga toxin profiles were compared after 30 min co-incubation with epithelial cells.
2010-07-22 | GSE20397 | GEO
Project description:The effect of pooled immunoglobulins (IgG) on E. coli O157:H7 colonization and the course of disease in an EHEC mouse model was investigated showing an improved survival and decreased intestinal and renal pathology. Treatment was given after inoculation thereby corresponding to the clinical setting. In vitro studies identified E. coli serine protease EspP as the E. coli O157:H7 protein that IgG bound to, via the Fc fragment, in both murine and human IgG preparations, and blocked its enzymatic activity. EspP is a virulence factor previously shown to promote colonic cell injury and the uptake of Shiga toxin by intestinal cells. The results suggest that IgG in commercial preparations binds to EspP protecting the host from E. coli O157:H7 infection and could potentially be beneficial in patients.
2022-02-08 | PXD029563 | Pride
Project description:Shiga toxin-producing Escherichia coli (STEC) O157:H7 is a notorious foodborne pathogen capable of causing severe gastrointestinal infections in humans. The bovine rectoanal junction (RAJ) has been identified as a primary reservoir of STEC O157:H7, playing a critical role in its transmission to humans through contaminated food sources. Despite the relevance of this host-pathogen interaction, the molecular mechanisms behind the adaptation of STEC O157:H7 in the bovine RAJ and its subsequent infection of human colonic epithelial cells remain largely unexplored. This study aimed to unravel the intricate dynamics of STEC O157:H7 in two distinct host environments: bovine RAJ squamous epithelial (RSE) cells and human colonic epithelial cells. Comparative transcriptomics analysis was employed to investigate the differential gene expression profiles of STEC O157:H7 during its interaction with these cell types. The bacterial cells were cultured under controlled conditions to simulate the microenvironments of both bovine RAJ and human colonic epithelial cells. Using high-throughput RNA sequencing, we identified key bacterial genes and regulatory pathways that are significantly modulated in response to each specific host environment. Our findings reveal distinct expression patterns of virulence factors, adhesion proteins, and stress response genes in STEC O157:H7 grown in bovine RAJ cells as opposed to human colonic epithelial cells. Additionally, the comparative analysis highlights the potential role of certain genes in host adaptation and tissue-specific pathogenicity. Furthermore, this study sheds light on the potential factors contributing to the survival and persistence of STEC O157:H7 in the bovine reservoir and its ability to colonize and cause disease in humans.
2023-11-09 | GSE240423 | GEO
Project description:Escherichia coli O157:H7 strains have been classified into different genotypes based on the presence of specific shiga toxin-encoding bacteriophage insertion sites. Genotypes that are predominant in clinical isolates are named clinical genotypes and those that are isolated mostly from bovine sources are bovine-biased genotypes. To determine whether inherent differences in gene expression could possibly explain the variation in infectivity of these genotypes, we compared the expression patterns of O157:H7 strains isolated from cattle, which belonged to either clinical genotype 1 or bovine-biased genotype 5. Important virulence factors of O157, including locus of enterocyte effacement, enterohemolysin, and pO157 plasmid encoded genes, showed increased expression in clinical genotype. Genes essential for acid resistance such as gadA, gadB, and gadC and other stress fitness-associated genes were up-regulated in the bovine-biased genotype 5. Overall, these results suggest that clinical genotype 1 strains more commonly cause human illness because of an enhanced ability to express O157 virulence factors known to be important for disease pathogenesis. By contrast, strains of the bovine-biased genotype 5 appear to be more resistant to adverse environmental conditions, which enable them to survive well in bovines without causing disease.
2009-04-24 | GSE15783 | GEO
Project description:The human intestinal microbiota associated with rats produces in vivo a soluble(s) factor(s) that down-regulates the expression of genes encoding for the Shiga toxin II in E. coli O157:H7. The Shiga toxin II is one of the major virulence factors of E. coli enterohemorragic leading to the deadly hemolitic and uremic syndrome. Investigation of the effect of the human intestinal microbiota on the whole transcriptome of EHEC O157:H7 is of major importance to increase our understanding of the pathogen transcriptomic adaptation in response to the human microbiota. We analysed by microarray hybridization the gene expression pattern of EHEC O157:H7 grown in the caecal content of germ-free rats or rats associated with the human microbiota of a healthy human subject. By doing so, we increased our understanding of the regulatory activities of the human gut microbiota on E. coli O157:H7 A first group of twelve weeks old, male, germfree rats was colonized with the human fecal microbiota and a second group was kept germfree and condidered as a controle group. Rats were fed for two weeks with a sterile human type diet, and were sacrificed. E. coli O157:H7 was cultivated for 6 hours in the caecal content of germfree rats and rats associated with the human intestinal microbiota. RNAs were extracted and cDNAs were synthesized, fragmented and biotinylated before being hybridized on Affymetrix E. coli genome 2.0 arrays. The effect of the human intestinal microbiota was investigated by comparing the gene expression level in the caecal content of rats associated with the human microbiota with their expression level in the caecal content of the germfree rats.
2013-09-10 | E-GEOD-37095 | biostudies-arrayexpress
Project description:The existence of two separate lineages of Escherichia coli O157:H7 has previously been reported, and research indicates that one of these lineages (lineage I) might be more pathogenic towards human hosts. We have previously shown that the more pathogenic lineage expresses higher levels of Shiga toxin 2 (Stx2) than the non-pathogenic lineage II. To evaluate why lineage 2 isolates do not express appreciable levels of toxin, two lineage 2 isolates (FRIK966 and FRIK2000) were chosen as representatives of lineage 2 and whole genome microarrays were performed using Agilent microarrays using the E. coli O157:H7 EDL933 lineage I clinical type isolate as a reference. Microarray results were utilized to evaluate what genes and pathways might be missing or differentially expressed. Quantitative RT-PCR was utilized to validate the microarray data.
2009-09-01 | GSE17070 | GEO
Project description:Multiple infection sources for enterohemorrhagic Escherichia coli O157:H7 are known, including food of animal origin and produce. The ecology of this pathogen outside its human host is largely unknown. One third of its annotated genes still are hypothetical. To identify genetic determinants expressed under environmental factors, we applied strand-specific RNA-sequencing of strain E. coli EDL933 under 11 different biotic and abiotic conditions: LB medium at pH4, pH7, pH9, or at 15°C; LB with nitrite or trimethoprim-sulfamethoxazole; LB-agar surface, M9 minimal medium, spinach leaf juice, surface of living radish sprouts, and cattle feces. Of 5379 annotated genes, only 144 are transcriptionally completely inactive under all conditions. Of 1,771 hypothetical genes, 1,672 exhibit significant transcriptional signals under at least one condition. The pathogenicity island LEE showed highest transcriptional activity in LB medium, minimal medium, and after treatment with antibiotics. Unique sets of genes, including many hypothetical genes, are highly up regulated on radish sprouts, cattle feces, or in the presence of antibiotics. For instance, azoR is biotechnologically important, but its environmental function has been elusive. This gene is highly active on radish sprouts. Further, we observed induction of the shiga-toxin carrying phages by antibiotics and confirmed active biofilm related genes on radish sprouts, in cattle feces, and on agar plates. Thus, environmental transcriptomics uncovers hitherto unknown gene functions and regulatory patterns of Escherichia coli O157:H7.
2014-07-20 | GSE48199 | GEO