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:The complex reservoir of metabolite-producing bacteria in the gastrointestinal tract contributes tremendously to human health and disease. Bacterial composition, and by extension gut metabolomic composition, is undoubtably influenced by the use of modern antibiotics. Herein, we demonstrate that polymyxin B, a last resort antibiotic used for chronic multidrug resistant infections infections, influences the production of the genotoxic metabolite colibactin from adherent-invasive Escherichia coli (AIEC) NC101. Colibactin can augment colorectal cancer (CRC) through DNA double stranded breaks and interstrand crosslinks. While the structure and biosynthesis of colibactin has been elucidated, chemical-induced regulation of its biosynthetic gene cluster and subsequent production of the genotoxin by pathogenic E. coli are largely unexplored. This research highlights the regulation of the colibactin-producing biosynthetic gene cluster under polymyxin stress. Using a multi-omic approach, we have identified that polymyxin stress enhances the abundance of colibactin biosynthesis proteins (Clb’s) in multiple pks+ E. coli strains, including pro-carcinogenic AIEC: NC101, the probiotic strain: E. coli Nissle 1917, and the antibiotic testing strain: E. coli ATCC 25922. Expression analysis via qPCR revealed that increased transcription of clb genes likely contributes to elevated Clb protein levels in NC101. Enhanced production of Clb’s by NC101 under polymyxin stress matched an increased production of the colibactin prodrug motif, a proxy for the mature genotoxic metabolite. Furthermore, E. coli with heightened tolerance for polymyxin antibiotics induced greater DNA damage, assessed by quantification of γH2AX staining in cultured intestinal epithelial cells. This study establishes a key link between the polymyxin B stress response and colibactin production in pks+ E. coli. Ultimately, our findings will inform future studies investigating colibactin regulation, the microbial response to antibiotics in the gut, and the ability of seemingly innocuous commensal microbes to induce host disease.
Project description:We observed that deletion of polyketide synthase (pks) from E. coli NC101 reduces its ability to induce tumors in interleukin-10 knockout (Il10-/-) mice injected with azoxymethane (AOM), without altering histologic inflammation. The goal of this experiment is to assess inflammatory cytokine levels in colonic tissue of these mice. 2 germ-free Il10-/- mice were assayed and used as controls. 3 E. coli NC101 and 3 E. coli NC101-delta-pks monoassociated mice were experimental samples.
Project description:we designed a CRISPR-based chromosome-doubling technique to construct an artificial diploid Escherichia coli cell. The stable diploid E. coli was confirmed by quantitative PCR and third-generation genome sequencing.
Project description:Counting DNA reads using whole genome sequencing is providing new insight into DNA double-strand break repair (DSBR) in the model organism Escherichia coli. We describe the application of RecA chromatin immunoprecipitation coupled to genomic DNA sequencing (RecA-ChIP-seq) and marker frequency analysis (MFA) to analyse the genomic consequences of DSBR.
Project description:Purpose: In this study, Escherichia coli DH5alpha whole transcriptome sequencing was performed in order to compare the different gene expression profiles between control and exposed to Wi-Fi radiofrequency radiations. Methods:Escherichia coli DH5alpha were exposed to Wi-Fi radiations. Total RNA samples( control and exposed ) were extracted by bacteria protect-Rneasy kit,treated with DNAase and subjected to sequnecing using an Illumina-NovaSeq 6000 platform. Library preparation and sequencing were performed by Macrogen (south korea).Trimmed reads are mapped to reference genome with Bowtie. HTseq was used for expression profiling. Expression profile was calculated for each sample and gene as read count.
Project description:We observed that interleukin-10 knockout (Il10-/-) mice injected with azoxymethane (AOM) and monoassociated with E. coli NC101, but not E. faecalis OG1RF, develop tumors. Histologic inflammation is not different in mice monoassociated with either bacterium. The goal of this experiment is to assess inflammatory cytokine levels in colonic tissue of these mice.
