Project description:Many reports show an association between the Pst system, the Pho regulon related genes and bacterial virulence. Our previous results showed that a functional Pst system is required for full virulence, resistance to serum, polymyxin B and acid shock. However, the interplay between the Pst system and virulence has an unknown molecular basis. To understand global APEC virulent strain responses to Pho regulon activation, we conducted transcriptome profiling experiments comparing the APEC chi7122 strain and its isogenic Pst mutant grown in rich phosphate medium using the Affymetrix GeneChip® E. coli Genome 2.0 Array. The Affymetrix GeneChip® E. coli Genome 2.0 Array contains the genome of the E. coli MG1655 and three pathogenic E. coli strain (EDL933, Sakai and CFT073) representing 20,366 genes. While comparing genes expression between Pst mutant and the wild type chi7122 strain, 471 genes are either up- (254) or down-regulated (217) of at least 1.5-fold, with a p-value inferior or equal to 0.05 and a false discovery rate of 2.71%. Keywords: Escherichia coli, phosphate starvation response, Pho regulon, Pst system, Affymetrix, transcriptional analysis
Project description:Avian Pathogenic Escherichia coli (APEC) are a group of extra-intestinal E. coli that infect poultry, and are able to cause a variety of diseases, systemic or localized, collectively designated as colibacillosis. Colibacillosis is the most common bacterial illness in poultry production, resulting in significant economic losses world-wide. Despite of its importance, pathogenicity mechanisms of APEC strains remain not completelly elucidated and available vaccines are not fully effectives. In order to better understand which genes could be related to pathogenicity in different APEC isolated, a microarray analyses of two APEC strains representing: Swollen Head Syndrome and Omphalitis was carried out.
Project description:Avian Pathogenic Escherichia coli (APEC) are a group of extra-intestinal E. coli that infect poultry, and are able to cause a variety of diseases, systemic or localized, collectively designated as colibacillosis. Colibacillosis is the most common bacterial illness in poultry production, resulting in significant economic losses world-wide. Despite of its importance, pathogenicity mechanisms of APEC strains remain not completelly elucidated and available vaccines are not fully effectives. In order to better understand which genes could be related to pathogenicity in different APEC isolated, a microarray analyses of two APEC strains representing: Swollen Head Syndrome and Omphalitis was carried out. We used the microarray methodology to evaluate the expression profile of two different APEC strains
Project description:Avian pathogenic Escherichia coli strains frequently cause extra-intestinal infections and are responsible for significant economic losses in the poultry industry worldwide. APEC isolates are closely related to human extraintestinal pathogenic E.coli strains and may also act as pathogens for humans. In this work, three type VI secretion systems were deleted to analyze which pathogenicity characteristics would change in the mutants, compared to wild type strain (SEPT 362). Four Avian Pathogenic Escherichia coli strains (one wild type and three deleted mutants) were grown at 37°C in Dulbecco´s Modified Eagle´s Media (DMEM) media until reach O.D 600 = 0.8, for RNA extraction and hybridization on Affymatrix microarrays.
Project description:Avian pathogenic Escherichia coli strains frequently cause extra-intestinal infections and are responsible for significant economic losses in the poultry industry worldwide. APEC isolates are closely related to human extraintestinal pathogenic E.coli strains and may also act as pathogens for humans. In this work, three type VI secretion systems were deleted to analyze which pathogenicity characteristics would change in the mutants, compared to wild type strain (SEPT 362).
Project description:APEC most often infect chickens, turkeys, ducks, and other avian species, and therefore pose a significant economic burden on the poultry industry worldwide. Few studies have analyzed the genome-wide transcriptional profile of APEC during infection in vivo. In this study, we examined the genome-wide transcriptional response of APEC O2 strain E058 in an in vivo chicken infection model to better understand the factors necessary for APEC colonization, growth, and survival in vivo. An Affymetrix multigenome DNA microarray, which contains most of the genomic open reading frames of E. coli K-12 strain MG1655, uropathogenic E. coli strain CFT073, and E. coli O157:H7 strain EDL 933, was used to profile the gene expression in APEC E058.The genes highly expressed during infection were involved in metabolism, iron acquisition or transport, virulence, response to stress, and biological regulation. Many genes encoding putative or hypothetical proteins were also strongly upregulated, implying that some undiscovered mechanism may underlie APEC pathogenesis.
Project description:RNA-Seq was performed on Avian pathogenic E. coli (APEC) WT and mutant to investigate the pathogenicity of ArcA (Aerobic Respiratory Control), a global regulator important for E. coli’s adaptation from anaerobic to aerobic conditions and control of that bacterium’s enzymatic defenses against ROS.
Project description:Colisepticemia caused by avian pathogenic Escherichia coli (APEC) results in annual multimillion dollar losses to the poultry industry. Recent research suggests that APEC may have an important role in public health as well. Generally, colisepticemia follows a respiratory tract infection in which APEC penetrate the respiratory epithelium to enter the bloodstream. From the bloodstream, bacteria may spread to various internal organs resulting in perihepatitis, pericarditis, and other conditions. The aim of this study was to identify molecular mechanisms enabling APEC to survive and grow in the bloodstream. To do so, we compared the transcriptome of APEC O1 during growth in Luria-Bertani broth and chicken serum. Selected genes that were significantly up-regulated in chicken serum were then subjected to mutational analysis to confirm their role in APEC pathogenesis. Several categories of genes, predicted to contribute to adaptation and growth in the avian host, were identified. These included several known virulence genes and genes involved in adaptive metabolism, protein transport, biosynthesis pathways, stress resistance, and virulence regulation. Several genes with unknown function, which were localized to pathogenicity islands or APEC O1’s large virulence plasmid, were also identified, suggesting that they too contribute to survival in chicken serum. This genome-wide analysis provides novel insight into processes that are essential to APEC O1’s survival and growth in chicken serum. Two-condition experiment: LB vs. chicken serm; four biological replicates, independently grown and harvested.
Project description:APEC most often infect chickens, turkeys, ducks, and other avian species, and therefore pose a significant economic burden on the poultry industry worldwide. Few studies have analyzed the genome-wide transcriptional profile of APEC during infection in vivo. In this study, we examined the genome-wide transcriptional response of APEC O2 strain E058 in an in vivo chicken infection model to better understand the factors necessary for APEC colonization, growth, and survival in vivo. An Affymetrix multigenome DNA microarray, which contains most of the genomic open reading frames of E. coli K-12 strain MG1655, uropathogenic E. coli strain CFT073, and E. coli O157:H7 strain EDL 933, was used to profile the gene expression in APEC E058.The genes highly expressed during infection were involved in metabolism, iron acquisition or transport, virulence, response to stress, and biological regulation. Many genes encoding putative or hypothetical proteins were also strongly upregulated, implying that some undiscovered mechanism may underlie APEC pathogenesis. We identified the in vivo transcriptional response of APEC E058 bacteria collected directly from the blood of infected chickens. Significant differences in expression levels were detected between the in vivo expression profile and the in vitro expression profile in LB medium.
Project description:Colisepticemia caused by avian pathogenic Escherichia coli (APEC) results in annual multimillion dollar losses to the poultry industry. Recent research suggests that APEC may have an important role in public health as well. Generally, colisepticemia follows a respiratory tract infection in which APEC penetrate the respiratory epithelium to enter the bloodstream. From the bloodstream, bacteria may spread to various internal organs resulting in perihepatitis, pericarditis, and other conditions. The aim of this study was to identify molecular mechanisms enabling APEC to survive and grow in the bloodstream. To do so, we compared the transcriptome of APEC O1 during growth in Luria-Bertani broth and chicken serum. Selected genes that were significantly up-regulated in chicken serum were then subjected to mutational analysis to confirm their role in APEC pathogenesis. Several categories of genes, predicted to contribute to adaptation and growth in the avian host, were identified. These included several known virulence genes and genes involved in adaptive metabolism, protein transport, biosynthesis pathways, stress resistance, and virulence regulation. Several genes with unknown function, which were localized to pathogenicity islands or APEC O1’s large virulence plasmid, were also identified, suggesting that they too contribute to survival in chicken serum. This genome-wide analysis provides novel insight into processes that are essential to APEC O1’s survival and growth in chicken serum.