Project description:Multiple infection sources for enterohemorrhagic Escherichia coli O157:H7 are known, including food of animal origin and produce. The ecology of this pathogen outside its human host is largely unknown. One third of its annotated genes still are hypothetical. To identify genetic determinants expressed under environmental factors, we applied strand-specific RNA-sequencing of strain E. coli EDL933 under 11 different biotic and abiotic conditions: LB medium at pH4, pH7, pH9, or at 15°C; LB with nitrite or trimethoprim-sulfamethoxazole; LB-agar surface, M9 minimal medium, spinach leaf juice, surface of living radish sprouts, and cattle feces. Of 5379 annotated genes, only 144 are transcriptionally completely inactive under all conditions. Of 1,771 hypothetical genes, 1,672 exhibit significant transcriptional signals under at least one condition. The pathogenicity island LEE showed highest transcriptional activity in LB medium, minimal medium, and after treatment with antibiotics. Unique sets of genes, including many hypothetical genes, are highly up regulated on radish sprouts, cattle feces, or in the presence of antibiotics. For instance, azoR is biotechnologically important, but its environmental function has been elusive. This gene is highly active on radish sprouts. Further, we observed induction of the shiga-toxin carrying phages by antibiotics and confirmed active biofilm related genes on radish sprouts, in cattle feces, and on agar plates. Thus, environmental transcriptomics uncovers hitherto unknown gene functions and regulatory patterns of Escherichia coli O157:H7.
Project description:Multiple infection sources for enterohemorrhagic Escherichia coli O157:H7 are known, including food of animal origin and produce. The ecology of this pathogen outside its human host is largely unknown. One third of its annotated genes still are hypothetical. To identify genetic determinants expressed under environmental factors, we applied strand-specific RNA-sequencing of strain E. coli EDL933 under 11 different biotic and abiotic conditions: LB medium at pH4, pH7, pH9, or at 15°C; LB with nitrite or trimethoprim-sulfamethoxazole; LB-agar surface, M9 minimal medium, spinach leaf juice, surface of living radish sprouts, and cattle feces. Of 5379 annotated genes, only 144 are transcriptionally completely inactive under all conditions. Of 1,771 hypothetical genes, 1,672 exhibit significant transcriptional signals under at least one condition. The pathogenicity island LEE showed highest transcriptional activity in LB medium, minimal medium, and after treatment with antibiotics. Unique sets of genes, including many hypothetical genes, are highly up regulated on radish sprouts, cattle feces, or in the presence of antibiotics. For instance, azoR is biotechnologically important, but its environmental function has been elusive. This gene is highly active on radish sprouts. Further, we observed induction of the shiga-toxin carrying phages by antibiotics and confirmed active biofilm related genes on radish sprouts, in cattle feces, and on agar plates. Thus, environmental transcriptomics uncovers hitherto unknown gene functions and regulatory patterns of Escherichia coli O157:H7. Eleven different conditions were sequenced on the SOLiD system. Of two of the condtions, spinach medium and LB-nitrite, technical replicates were sequenced. Of LB medium and radish sprouts, biological replicates were sequenced on an Illumina MiSeq.
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:The purpose of this study is to determine whether the presence of pathogenic Escherichia coli in colon is associated with psychiatric disorders.
| 2230352 | ecrin-mdr-crc
Project description:Genomic Analysis of 3rd generation cephalosporin resistant Escherichia coli from dairy cow manure
Project description:Production of cephalosporin precursors with recombinant strains of Penicillium chrysogenum has improved the economics and reduced the environmental impact of industrial cephalosporin production. The engineered P. chrysogenum strains used in these processes express heterologous enzymes that convert the intermediate acyl-6-aminopenicillanic acid into different tailor-made compounds. Activation of the cephalosporin side-chain precursor to its corresponding CoA thioester is an essential step for its incorporation into the β-lactam backbone. To identify the acyl-CoA ligase involved in activation of adipic acid, a frequently used cephalosporin side-chain precursor, we searched the genome of P.chrysogenum for putative structural genes encoding acyl-CoA ligases. Chemostat-based transcriptome analysis was then used to identify the one presenting the highest expression level when cells were grown in the presence of adipic acid. Deletion of the gene renamed aclA, led to a 32% decreased specific rate of adipic acid consumption and a three-fold reduction of adipoyl-6-aminopenicillanic acid levels in chemostat cultures of P. chrysogenum, but did not affect penicillin production. After cloning the gene and overexpressing it in Escherichia coli, its purified protein product was shown to have adipoyl-CoA ligase, but no phenylacetyl-CoA ligtase activity. Finally, by fusing the gene to a sequence encoding cyan fluorescent protein, the resulting fusion protein localized to microbodies, which indicates that activation of the side-chain precursor adipic acid takes place in this compartment, where also the subsequent acyltransferase step takes place. Identification and functional characterization of this adipoyl-CoA ligtase gene may aid in developing future metabolic engineering strategies for improving the production of different cephalosporins.