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:Understand the mechanisms of evolution in large-scale bio-production by tracking population dynamics leading to production decline in mevalonic acid-producing Escherichia coli. Industrial bioproduction entails growth of the production host to large bioreactors (e.g. 1-300 m3). This may put the organism at risk for generating non-producing subpopulations of genetic heterogeneity, which is not phenotypically detected at lab-scale (e.g. 2 L). To study these dynamics, we experimentally simulated these growth durations by passing mevalonic acid-producing E. coli to maintain the populations in exponential growth for 45 generations.
Project description:Responses of Escherichia coli DH5alpha as they overexpress pUC at different ODs in LB + Amp Escherichia coli DH5alpha expressing pUC sampled at different ODs (0.2, 0.5, 0.9) in LB + Amp vs cells not producing pUC
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:We report the effect of oxygenation state in lactose grown escherichia coli producing recombinant proteins. To shed more light on the mechanistic correlation between the uptake of lactose and dissolved oxygen, a comprehensive study has been undertaken with the E. coli BL21 (DE3) strain. Differences in consumption pattern of lactose, metabolites, biomass and product formation due to aerobiosis have been investigated. Transcriptomic profiling of metabolic changes due to aerobic process and microaerobic process during protein formation phase has been studied and the results provide a deeper understanding of protein production in E. coli BL21 (DE3) strains with lactose based promoter expression systems.This study also provides a scientific understanding of escherichia coli metabolism upon oxygen fluctuations.
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:Various species of the intestinal microbiota have been associated with the
development of colorectal cancer (CRC), yet a direct role of bacteria in the
occurrence of oncogenic mutations has not been established. Escherichia coli can
carry the pathogenicity island pks, which encodes a set of enzymes that
synthesize colibactin. This compound alkylates DNA on adenine residues and
induces double strand breaks in cultured cells. Here, we exposed human intestinal
organoids to genotoxic pks+ Escherichia coli by repeated luminal injection over a
period of 5 months. Whole genome sequencing (WGS) of clonal organoids before
and after this exposure reveals a distinct mutational signature, absent from
organoids injected with isogenic pks-mutant bacteria. The same mutational
signature is detected in a subset of 3668 human metastatic cancer genomes,
predominantly in a subset of CRC cases. Our study describes a distinct mutational
signature in CRC and implies that the underlying mutational process directly
results from past exposure to bacteria carrying the colibactin-producing pks
pathogenicity island.
Project description:Shiga toxin type 2 (Stx2) is the main virulence factor produced by Stx-producing Escherichia coli (STEC) responsible for hemorrhagic colitis and the life-threatening sequela hemolytic uremic syndrome.
