Project description:Transcript abundance in Escherichia coli O157:H7 was determined in the presence or absence of pulsed expression of the small RNA, AsxR. AsxR was cloned under the control the arabinose inducible promoter Para. Escherichia coli O157:H7 str. TUV93-0 with pAsxR or empty vector was cultured in MEM-HEPES media to an OD600 of 0.8 and 0.2% arabinose added. 10min after addition of arabinose 10ml of cells were harvested and and pellets resuspended in 1ml of Trizol and total RNA isolated. RNAs were labelled using the SuperScript Plus indirect cDNA labelling System. Triplicate control RNAs were pooled and hybridised to seperate AsxR test RNAs on three microarays. Arrays were hybridised using the Maui hybridisation platform and Scann using and Axon Autoloader Scanner. GenePix software was used to analyse images and GPR files were analysed using Genespring 7.3.1.
Project description:The intention of this study is to analyse the effect of antibiotics on the gene expression of Escherichia coli. Shaking-flask cultivations of Escherichia coli K12GFP-UTL2 were carried out with a medium containing nalidixic acid. Cultures with antibiotic-free medium, which were run in an identical way, served as reference. Samples were taken at different times during the cultivations, the RNA was isolated and hybridised on whole genome yeast microarrays. Keywords: Influence of toxins on gene expression in E. coli
Project description:In large-scale production processes, metabolic control is typically achieved by limited supply of essential nutrients like glucose or ammonia. With increasing bioreactor dimensions, microbial producers such as Escherichia coli are exposed to changing substrate availabilities due to limited mixing. In turn, cells sense and respond to these dynamic conditions leading to frequent activation of their regulatory programs. Previously, we characterized short- and long-term strategies of cells to adapt to glucose fluctuations. Here, we focused on fluctuating ammonia supply, while studying a continuously running two-compartment bioreactor system comprising a stirred tank reactor (STR) and a plug flow reactor (PFR). Genes were repeatedly switched on/off when E. coli returned to the STR. Moreover, E. coli revealed highly diverging long-term transcriptional responses in ammonia compared to glucose fluctuations. The identification of target genes may help to create robust cells and processes for large-scale application.
Project description:The intention of this study is to analyse the effect of antibiotics on the gene expression of Escherichia coli. Shaking-flask cultivations of Escherichia coli K12GFP-UTL2 were carried out with a medium containing nalidixic acid. Cultures with antibiotic-free medium, which were run in an identical way, served as reference. Samples were taken at different times during the cultivations, the RNA was isolated and hybridised on whole genome yeast microarrays. Keywords: Influence of toxins on gene expression in E. coli A timeserial experiment of the influence of nalidixic acid on the gene expression in Escherichia coli was performed. Effects of the growth curve were eliminated by bionformatic methods.
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:Six isolates of PT21/28 and six of PT32 were analysed by CGH using UBECarray3 microarrays (containing probes for E. coli K-12 str. MG1655 and O157:H7 str. EDL933 and Sakai) to define genotypic differences between phage types. gDNA from E.coli O157 str. Sakai was hybridised to all arrays to provide a universal control channel on all arrays.
Project description:To explore the circulating miRNA expression after subcutaneous injection of Gram negative and positive bacteria in the mice The recombinant specific Gram negative pathogens Escherichia coli (xen14) and Gram positive pathogens Staphyllococcus aureus (xen29) were purchased from the Caliper (Caliper, Princeton, NJ, USA). 1M-CM-^W108 Escherichia coli or Staphyllococcus aureus pathogen in 100 M-NM-<l PBS was injected subcutaneously with Fr. 25 needle into the back of the mice to cause bacterial infection of the mice. An extra group of animals was inoculated with PBS to serve as a negative control. The mice had access to food and water ad libitum both before and after bacteria injection. The mice were killed at the indicated time points (4, 8, and 24 h) after the bacteria injection, and whole blood was drawn.