Project description:A food-borne outbreak of haemorrhagic colitis (HC) and HUS caused by E. coli O103:H25 occurred in Norway, 2006. The outbreak included 17 registered cases, of which 10 developed HUS. The aim of this study was to characterize two E. coli O103:H25 isolates from this outbreak. Only one of the isolates carry the stx2 gene (by PCR). Since they have the same typing profile by typing method MLVA, we expect the isolates to have identical gene content except from an Stx2-encoding phage. Therefore, we further investigate whether the Stx2-encoding phage has any impact on the gene expression. Keywords: mixed, gene expression, comparative genomic hybridization Triplicate samples of mRNA from a test strain O157:H7 EDL933 and two outbreak strains - one Stx positive and one stx negative were co-hybridized with genomic DNA from the same strain. Triplicate samples of the Stx positive strain grown at acidic conditions was also co-hybridized with genomic DNA from the Stx positive strain. Genomic DNA for each strain is technical replicates only.
Project description:Use of whole-genome sequencing of Vibrio cholerae O1 isolates to assist the epidemiological investigation of a cholera outbreak in Zimbabwe, 2018
Project description:The present study used microarray approach to identify the genomewide response to cholera toxin in the presence of nitrate. Considering that fact that the possibility of the existence of multiple Gα genes/proteins in plants has not been conclusively ruled out, analysis of the genomewide impact of RGA1 mutation in rice and GPA1 mutation in Arabidopsis reveal only those genes that are under their direct control. On the other hand, assuming that all those different Gα subunits in any given plant are regulated by cholera toxin, analysis of the genomwide response to cholera toxin could capture the entire G-protein responsive transcriptome, beyond what can be revealed by the mutant approach. This could reveal even those genes that respond to other, as yet unidentified Gα subunits, as well as reveal some genes that are non-specifically regulated by cholera toxin, independent of any G-proteins.
Project description:A food-borne outbreak of haemorrhagic colitis (HC) and HUS caused by E. coli O103:H25 occurred in Norway, 2006. The outbreak included 17 registered cases, of which 10 developed HUS. The aim of this study was to characterize two E. coli O103:H25 isolates from this outbreak. Only one of the isolates carry the stx2 gene (by PCR). Since they have the same typing profile by typing method MLVA, we expect the isolates to have identical gene content except from an Stx2-encoding phage. Therefore, we further investigate whether the Stx2-encoding phage has any impact on the gene expression. Keywords: mixed, gene expression, comparative genomic hybridization
Project description:The molecular mechanisms involved in host pathogen interactions at mucosal surfaces needs to be better understood in order to develop immune-mediated methods of protection against pathogens. Cholera toxin (CT) has the rare ability for a protein of inducing robust mucosal immunity in the gut and is therefore an excellent model with which to determine mechanisms of adjuvanticity and immunogenicity at intestinal mucosal surfaces. Jejunal epithelial cells are one of the first sites of antigen encounter. Therefore a porcine intestinal epithelial cell line, IPEC-J2, was cultured in 6-well transwell plates in the presence or absence of 50 ng/ml cholera toxin for up to 8 hours and the cell layer was harvested for gene expression analysis using the Affymetrix porcine genome array and real-time PCR analysis. Affymetrix analysis identified, and real-time PCR analysis of 15 genes confirmed, an increase in gene expression for 59 genes and a decrease in gene expression for 14 genes under CT treatment. An 8 hour time course of expression revealed that by 2-4 hours after CT treatment, all 10 upregulated genes were differentially expressed and by 4-6 hours after CT treatment 3 of the 5 downregulated genes were differentially expressed. These data suggest that the potent mucosal adjuvanticity and immunogenicity of CT derives from rapid alterations in gene expression at the site of first antigen encounter with the immune system. Characterization of early immune gene expression may elucidate potential biological mechanisms for mucosal immune induction leading to the development of effective vaccines against enteric pathogens. Keywords: Treatment comparison, cholera toxin vs untreated at 8h time point
Project description:The molecular mechanisms involved in host pathogen interactions at mucosal surfaces needs to be better understood in order to develop immune-mediated methods of protection against pathogens. Cholera toxin (CT) has the rare ability for a protein of inducing robust mucosal immunity in the gut and is therefore an excellent model with which to determine mechanisms of adjuvanticity and immunogenicity at intestinal mucosal surfaces. Jejunal epithelial cells are one of the first sites of antigen encounter. Therefore a porcine intestinal epithelial cell line, IPEC-J2, was cultured in 6-well transwell plates in the presence or absence of 50 ng/ml cholera toxin for up to 8 hours and the cell layer was harvested for gene expression analysis using the Affymetrix porcine genome array and real-time PCR analysis. Affymetrix analysis identified, and real-time PCR analysis of 15 genes confirmed, an increase in gene expression for 59 genes and a decrease in gene expression for 14 genes under CT treatment. An 8 hour time course of expression revealed that by 2-4 hours after CT treatment, all 10 upregulated genes were differentially expressed and by 4-6 hours after CT treatment 3 of the 5 downregulated genes were differentially expressed. These data suggest that the potent mucosal adjuvanticity and immunogenicity of CT derives from rapid alterations in gene expression at the site of first antigen encounter with the immune system. Characterization of early immune gene expression may elucidate potential biological mechanisms for mucosal immune induction leading to the development of effective vaccines against enteric pathogens. Experiment Overall Design: Confluent IPEC-J2 cell monolayers were treated with or without 50 ng/ml cholera toxin in transwell dishes for 8h. The experiment was repeated 3 times for a total of 6 chips, 3 cholera toxin treated and 3 untreated. Gene expression was compared between cholera toxin treated and untreated cells.
Project description:The present study used microarray approach to identify the genomewide response to cholera toxin in the presence of nitrate. Considering that fact that the possibility of the existence of multiple GM-NM-1 genes/proteins in plants has not been conclusively ruled out, analysis of the genomewide impact of RGA1 mutation in rice and GPA1 mutation in Arabidopsis reveal only those genes that are under their direct control. On the other hand, assuming that all those different GM-NM-1 subunits in any given plant are regulated by cholera toxin, analysis of the genomwide response to cholera toxin could capture the entire G-protein responsive transcriptome, beyond what can be revealed by the mutant approach. This could reveal even those genes that respond to other, as yet unidentified GM-NM-1 subunits, as well as reveal some genes that are non-specifically regulated by cholera toxin, independent of any G-proteins. Total RNA was isolated from 10 day old excised rice leaves treated with or without cholera toxin in the presence of nitrate.Total RNA was first converted into cDNA and then into cRNA labeled with Cy3 and Cy5 dyes. These were hybridized on the 44K 60-mer whole genome arrays on glass slides. The slides were washed and scanned on an Agilent scanner (G2565B) at 100 % laser power. Data extraction was carried out with Agilent Feature Exiraction software (version 9.1). The experiment was repeated with a biological-cum-technical replicate where total RNA samples were isolated from a fresh batch of rice plants and the cRNAs were labeled with opposite dyes (dye-swap).