Project description:Here, we investigated the impact of Stx2 phage carriage on Escherichia coli (E. coli) K-12 MG1655 host gene expression. Using quantitative RNA-seq analysis, we compared the transcriptome of naïve MG1655 and the lysogens carrying the Stx2 phage of the 2011 E. coli O104:H4 outbreak strain or of the E. coli O157:H7 strain PA8, which share high degree of sequence similarity.
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: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:We compared the transcriptional profiles of 12 E. coli O157:H7 isolates grown to stationary phase in LB broth. These isolates possess the same two enzyme PFGE profile and are related temporally or geographically to the above outbreak. These E. coli O157:H7 isolates included three clinical isolates, five isolates from separate bags of spinach, and single isolates from pasture soil, river water, cow feces, and a feral pig.
Project description:In 2011, in Germany, Escherichia coli O104:H4 caused the enterohemorrhagic E. coli (EHEC) outbreak with the highest incidence rate of hemolytic uremic syndrome. This pathogen carries an exceptionally potent combination of EHEC- and enteroaggregative E. coli (EAEC)-specific virulence factors. Here, we identified an E. coli O104:H4 isolate that carried a single nucleotide polymorphism (SNP) in the start codon (ATG>ATA) of rpoS, encoding the alternative sigma factor S. The rpoS ATG>ATA SNP was associated with enhanced EAEC-specific virulence gene expression. Deletion of rpoS in E. coli O104:H4 Dstx2 and typical EAEC resulted in a similar effect. Both rpoS ATG>ATA and DrpoS strains exhibited stronger virulence-related phenotypes in comparison to wild type. Using promoter-reporter gene fusions, we demonstrated that wild-type RpoS repressed aggR, encoding the main regulator of EAEC virulence. In summary, our work demonstrates that RpoS acts as a global repressor of E. coli O104:H4 virulence, primarily through an AggR-dependent mechanism.
Project description:The purpose of this study is to determine whether the presence of pathogenic Escherichia coli in colon is associated with psychiatric disorders.
Project description:Despite the characterization of many aetiologic genetic changes. The specific causative factors in the development of sporadic colorectal cancer remain unclear. This study was performed to detect the possible role of Enteropathogenic Escherichia coli (EPEC) in developing colorectal carcinoma.
Project description:Antibiotic resistance associated with the expression of the clinically significant carbapenemases, IMP, KPC, and NDM and OXA-48 in Enterobacteriaceae is emerging as a worldwide calamity to health care. In Australia, IMP-producing Enterobacteriaceae is the most prevalent carbapenemase-producing Enterobacteriaceae (CPE). Genomic characteristics of such carbapenemase-producing Enterobacteriaceae (CPE) are well described, but the corresponding proteome is poorly characterised. We have thus developed a method to analyse dynamic changes in the proteome of CPE under antibiotic pressure. Specifically, we have investigated the effect of meropenem at sub-lethal concentrations to develop a better understanding of how antibiotic pressure leads to resistance. Escherichia coli, producing either NDM, IMP or KPC type carbapenemase were included in this study, and their proteomes were analysed in growth conditions with or without meropenem.
Project description:Nucleic Acid Sequencing for the study of division induced double strand breaks in the terminus region of Escherichia coli cells lacking RecBCD DNA repair enzymes.
Project description:We compared the transcriptional profiles of 12 E. coli O157:H7 isolates grown to stationary phase in LB broth. These isolates possess the same two enzyme PFGE profile and are related temporally or geographically to the above outbreak. These E. coli O157:H7 isolates included three clinical isolates, five isolates from separate bags of spinach, and single isolates from pasture soil, river water, cow feces, and a feral pig. Twelve condition experiment, 12 E. coli O157:H7 isolates. Two biological replicates for isolates RM6067, RM6069, RM6101, RM6102, RM6103, RM6149, RM6655, RM6658, RM9992, RM9997, RM9998 and RM10002 independently grown to stationary phase in LB at 37°C and harvested. One replicate per array. A type 2 gene expression experimental design was used, with fluorescently labeled genomic DNA as a reference channel in each experiment as described by Lucchini, S., et al. 2005. Infect Immun 73:88-102.
