Project description:Atypical enteropathogenic Escherichia coli (aEPEC) is amongst the leading causes of diarrheal disease worldwide. The colonization of the gut mucosa by aEPEC results in actin pedestal formation at the site of bacterial attachment. This cytoskeletal rearrangement is triggered by the interaction between the bacterial adhesin intimin and its receptor Tir, which is translocated through the type three secretion system, to the host cell. While some aEPEC require tyrosine phosphorylation of Tir and recruitment of the host Nck to trigger actin polymerization, certain aEPEC strains, whose Tir is not phosphorylated, rely on the effector EspFu for efficient actin remodeling. To understand how the host responds to these different actin polymerization signaling pathways, we analyzed gene expression changes in epithelial cells infected with pedestal-forming aEPEC strains using high-throughput RNA sequencing (RNA-seq).
Project description:Extraintestinal pathogenic Escherichia coli (ExPEC) is a common bacterial strain causing diverse diseases in humans and animals. To analyse the detailed mechanisms underlying ExPEC-mediated sepsis in humans, the transcriptome response of mice at 3h,6h, and 12h after ExPEC infection was analyzed by RNA-seq of mouse spleen samples.
Project description:Atypical EPEC (aEPEC) strains are part of group of pathogens capable of forming the Attaching and Effacing (A/E) lesion. This lesion is characterized by intimate adherence of bacteria to enterocytes, and microvilli destruction. The genes responsible to cause that lesion are located in a pathogenicity island called Locus of Enterocyte Effacement (LEE). Transcription of LEE genes is subjected to various levels of regulation, including quorum sensing through autoinducer 3 (AI-3) system. AI-3 is an aromatic compound with similar characteristics to the epinephrine and norepinephrine hormones. This similarity allows bacteria to use these hormones and AI-3 to perform cell M-bM-^@M-^S to M-bM-^@M-^S cell signaling processes and bacteria - host communication processes in order to modulate its virulence. AI-3, epinephrine and norepinephrine are detected by a sensor kinase named quorum sensing E.coli regulator (QseC). In order to investigate the role of QseC and epinephrine in atypical EPEC O55:H7 virulence, we constructed a QseC mutant of this strain and performed transcription and phenotypic analyses in the presence or absence of epinephrine. We have reported here, for the first time, the quorum sensing QseC regulation of virulence genes in atypical EPEC. Our results shown that QseC is a global regulator of gene expression in aEPEC and positively regulates flagellar genes, LEE and non-LEE encoded factors. We also have shown that the presence of epinephrine could be sensed by other receptor that acts as negative regulator of LEE4 and LEE5 genes. Comparison of transcriptional regulation of enteropathogenic E. coli serotype O55:H7 wild type and the qseC mutant in the absence or presence of epinephrine signal to identify the regulated targets
Project description:To investigate the regulatory targets of the RegR virulence regulon of rabbit specific enteropathogenic Escherichia coli strain E22
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:Primary objectives: The study investigates whether a Escherichia coli Nissle-suspenison has a (preventive) antidiarrheal effect in patients with tumors who are treated with chemotherapeutic schemes which are associated with increased occurances of diarrhea. Diarrhea caused by treatment are thought to be reduced in intensity and/or frequency by the treatment with Escherichia coli Nissle-Suspension.
Primary endpoints: Common toxicity criteria (CTC) for diarrhea
Project description:Extraintestinal pathogenic Escherichia coli (ExPEC) have a capacity to cause serious infections of blood, the central nervous system and particularly the urinary tract. Relatively little is known about how ExPEC adapt their cell-wide protein expression to environments with different carbon sources and other required nutrients. We used label-free quantitative (LFQ) proteomic analysis to determine proteomes of five ExPEC strains purified from clinical blood cultures, and compared them with proteomes of reference uropathogenic E. coli strain 536 derived from blood culture and two chemically different solid media. We identified 2,883 proteins in total, and for 90% of the detected proteins described their relative quantitative levels based on LFQ intensity scores. Comparison of anaerobic and aerobic blood cultures revealed significant differences in the levels of 32 proteins out of 1854 shared proteins. A majority of these proteins was associated with acquisition and utilization of metal ions, which are critical either for anaerobic (nickel) or aerobic (iron) respiration. ANOVA analysis of the relative quantitative levels of 1758 proteins shared between the strains identified 47 differentially expressed proteins, including proteins involved in vitamin B6 metabolism, cell motility and virulence. Comparison of strain 536 proteomes derived from blood cultures and solid media showed substantial variation in the relative quantitative levels of 200 proteins, which represented 11% of the common proteins between the conditions. Blood culture condition was characteristic by upregulation of anaerobic fermentative metabolism, cell motility and iron utilization. In a response to the growth on solid media increased levels of proteins functional in aerobic respiration, catabolism of various biochemicals obtained from the media and protection against environmental stresses. The study presents the largest coverage of ExPEC/UPEC proteome to date,with a detail account of ExPEC metabolism under three chemically different environments.
Project description:To investigate the regulatory targets of the RegR virulence regulon of rabbit specific enteropathogenic Escherichia coli strain E22 Single factor (genotype) with dye swaps.
