Project description:Comparative genomic hybridization between Escherichia coli strains to determine core and pan genome content of clinical and environmental isolates
Project description:Comparative genomic hybridization between Escherichia coli strains to determine core and pan genome content of clinical and environmental isolates Two color experiment, Escherichia coli Sakai (reference), clinical and environmental Escherichia coli strains (testers): At least two replicates including a single dye swap for each reference-tester comparison
Project description:Transcriptional profiling of Asymptomatic Bacteriuria (ABU) Escherichia coli strain 83972 comparing the progenitor wild type strain ABU83972 with its re-isolates from human bladder colonization (PI-2, PII-4, PIII-4) and in vitro cultivation experiment (4.9). Wild type vs. re-isolate cells. Biological replicates: 3 wild type, 3 re-isolates, independently grown and harvested. One replicate per array.
Project description:Escherichia coli bloodstream infections are common and associated with high mortality. A key feature of E. coli is the lipopolysaccharide (LPS) O-antigen, which contributes to immune evasion during invasive infection. We analyzed serial E. coli isolates from patients with relapsed bacteremia and identified frequent disruption of O-antigen synthesis due to mutations in wbbL, resulting in a rough LPS (R-LPS) phenotype. E. coli with rough LPS isolates were more serum sensitive and less pathogenic in mice. Despite this apparent attenuation, 11 of 66 (18%) E. coli sequence type 131 bloodstream isolates in our cohort lacked O-antigen and were associated with significantly worse clinical outcomes, including septic shock and mortality. Using a recurrent bacteremia model, we show that R-LPS isolates partially evade protective immunity generated against smooth-LPS E. coli, highlighting the importance of host immune context in invasive disease.
Project description:Transcriptional profiling of Asymptomatic Bacteriuria (ABU) Escherichia coli strain 83972 comparing the progenitor wild type strain ABU83972 with its re-isolates from human bladder colonization (PI-2, PII-4, PIII-4) and in vitro cultivation experiment (4.9).
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.
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: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:This series presents normalized gene expression profiles of three Escherichia coli K-12 MG1655-derived strains (pygYFP, Y5, and Y6). Strains Y5 and Y6 were originally isolated from 3-week-old aging colonies, but RNA for transcriptomic profiling was extracted from 7-day-old colonies regrown under identical conditions. All samples were hybridized to the NimbleGen GPL9088 one-color microarray platform, and processed values correspond to RMA-normalized, non-log2 intensities. These data compare the parental strain to two evolved isolates carrying distinct regulatory and stress-response mutations, and can be used to study diversification and adaptive strategies emerging in aging bacterial colonies.
