Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1212877 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:A popular strategy for enhancing the antibacterial properties of probiotic bacteria is to retrofit them with the ability to overproduce heterologous bacteriocins. This is often achieved from strong, non-native promoters. How the dysregulated overproduction of heterologous bacteriocins affects the fitness and antibacterial efficacy of the retrofitted probiotic bacteria is often overlooked. We conferred the prototypical probiotic Escherichia coli strain Nissle (EcN) the ability to produce different amounts of the bacteriocin microcin C (McC). Expression of the bacteriocin synthesis genes was driven from the native promoter (Pmcc-WT), or from promoters manipulated to be stronger (Pmcc-High) and weaker (Pmcc-Low) than the WT, in a plasmid-based system. Pmcc-Low and Pmcc-High retained their native regulation. A strain harbouring a non-functional promoter (Pmcc-Mut) produces no McC and was used as a control. Each strain was grown to early stationary phase, when production of McC starts, in Luria-Bertani broth at 37 degrees. The RNA was isolated and the effects of different levels of production of McC on the transcriptome of EcN was examined by RNA-Seq.
2023-06-30 | E-MTAB-13078 | biostudies-arrayexpress
Project description:The Escherichia coli strain Nissle 1917 (EcN) is used as a probiotic for the treatment of certain gastrointestinal diseases in several European and non-European countries. In vitro studies showed EcN to efficiently inhibit the production of Shiga toxin (Stx) by Stx producing E. coli (STEC) such as Enterohemorrhagic E. coli (EHEC). The occurrence of the latest EHEC serotype (O104:H4) responsible for the great outbreak in 2011 in Germany was due to the infection of an enteroaggregative E. coli by a Stx 2-encoding lambdoid phage turning this E. coli into a lysogenic and subsequently into a Stx producing strain. Since EHEC infected persons are not recommended to be treated with antibiotics, EcN might be an alternative medication. However, because a harmless E. coli strain might be converted into a Stx-producer after becoming host to a stx encoding prophage, we tested EcN for stx-phage genome integration. Our experiments revealed the resistance of EcN towards not only stx-phages but also against the lambda phage. This resistance was not based on the lack of or by mutated phage receptors. Rather the expression of certain genes (superinfection exclusion B (sieB) and a phage repressor (pr) gene) of a defective prophage of EcN was involved in the complete resistance of EcN to infection by the stx- and lambda phage. Obviously, EcN cannot be turned into a Stx producer. Furthermore, we observed EcN to inactivate phages and thereby to protect E. coli K-12 strains against infection by stx- as well as lambda-phages. Inactivation of lambda-phages was due to binding of lambda-phages to LamB of EcN whereas inactivation of stx-phages was caused by a thermostable protein of EcN. These properties together with its ability to inhibit Stx production make EcN a good candidate for the prevention of illness caused by EHEC and probably for the treatment of already infected people.
2018-06-14 | GSE109932 | GEO
Project description:To build therapeutic strains, Escherichia coli Nissle (EcN) have been engineered to express antibiotics, toxin-degrading enzymes, immunoregulators, and anti-cancer chemotherapies. For efficacy, the recombinant genes need to be highly expressed, but this imposes a burden on the cell, and plasmids are difficult to maintain in the body. To address these problems, we have developed landing pads in the EcN genome and genetic circuits to control therapeutic gene expression. These tools were applied to EcN SYNB1618, undergoing clinical trials as a phenylketonuria treatment. The pathway for converting phenylalanine to trans-cinnamic acid was moved to a landing pad under the control of a circuit that keeps the pathway off during storage. The resulting strain (EcN SYN8784) achieved higher activity than EcN SYNB1618, reaching levels near when the pathway is carried on a plasmid. This work demonstrates a simple system for engineering EcN that aids quantitative strain design for therapeutics.
2023-05-15 | GSE228761 | GEO
Project description:To determine whether calprotectin can elicit any transcriptional response in the probiotic E. coli Nissle 1917(EcN), EcN was treated with 200 ug/g of calprotectin in log phase.
2023-08-16 | GSE211418 | GEO
Project description:Extracellular membrane vesicles (MVs) released by gut microbiota are key players in the communication with the host. Next-generation sequencing of small RNAs was used to quantify miRNA expression in monocyte-derived dendritic cells after 24 h-stimulation with MVs isolated from two E. coli intestinal isolates, the probiotic E. coli strain Nissle 1917 (EcN) and the commensal ECOR12. Analysis revealed miRNAs differentially expressed in response to MVs compared to immature control dendritic cells (log2fold-change > 0.7 and padj < 0.001). A common set of miRNAs was modulated by MVs from both strains (46 downregulated, 75 upregulated). In addition, these vesicles elicited differential expression of specific miRNAs depending on the producer strain (26 downregulated and 23 upregulated by EcN; 48 downregulated and 49 upregulated by ECOR12).
2020-06-25 | GSE144355 | GEO
Project description:Escherichia coli Nissle 1917 (EcN), a well-known Gram-negative probiotic bacterium, has been widely used to treat various intestinal disorders and has gained recognition as a promising platform for diverse biotechnological applications, validated by numerous institutions and researchers over the years However, despite its importance, developing suitable expression systems in EcN has been challenging due to the difficulty in meeting key criteria such as non-toxicity, biocompatibility, and tunable expression. Recently, we identified a gene cluster in EcN responsible for tagatose utilization, challenging the conventional belief that E. coli cannot metabolize tagatose. D-tagatose, a rare, low-calorie sugar naturally found in small amounts in dairy products and fruits, is recognized as safe by the FDA. Due to its poor digestibility in humans, only certain enteric microorganisms are capable of metabolizing it. In this study, we investigated the regulatory elements within this gene cluster using high-throughput differential RNA sequencing (dRNA-seq) and developed a tagatose-inducible expression plasmid, creating a tunable gene expression system for engineering EcN. We evaluated the performance of this novel system and successfully applied it to overproduce a pharmaceutical protein and an industrial enzyme under both aerobic and anaerobic conditions.
2025-02-19 | GSE280463 | GEO
Project description:Escherichia coli Nissle 1917 (EcN) is a probiotic used for treatment of intestinal disorders. EcN improves gastrointestinal homeostasis and microbiota balance; however little is known about how this probiotic delivers effector molecules to the host. Outer membrane vesicles (OMVs) are constitutively produced by gram-negative bacteria and have a relevant role in bacteria-host interactions. Here we performed proteomic analysis of EcN OMVs. Using 1D SDSD-PAGE and highly sensitive LC-MS/MS analysis we identified 192 EcN vesicular proteins with high confidence in three independent experiments. Of these proteins, 18 were encoded by strain-linked genes and 57 were common to pathogen-derived OMVs. These proteins may contribute to the ability of this probiotic to colonize the human gut as they fulfil functions related to adhesion to host tissues, immune modulation or bacterial survival in host niches. This study describes the first global OMV proteome of a probiotic strain and provides evidence that probiotic-derived OMVs contain proteins that can target these vesicles to the host and mediate their beneficial effects on intestinal function.
2013-12-19 | PXD000367 | Pride
Project description:Rapidly growing antibiotic resistance among gastrointestinal pathogens, and the ability of antibiotics to induce the virulence of these pathogens makes it increasingly difficult to rely on antibiotics to treat gastrointestinal infections. The probiotic E. coli strain Nissle 1917 (EcN) is the active component of the pharmaceutical preparation Mutaflor® and has been successfully used in the treatment of gastrointestinal disorders. Gut bacteriophages are dominant players in maintaining the microbial homeostasis in the gut, however, their interaction with incoming probiotic bacteria remains to be at conception. The presence of bacteriophages in the gut makes it inevitable for any probiotic bacteria to be phage resistant, in order to survive and successfully colonize the gut. This study addresses the phage resistance of EcN, specifically against lytic T4 phage infection. From various experiments we could show that i) EcN is resistant towards T4 phage infection, ii) EcN’s K5 polysaccharide capsule plays a crucial role in T4 phage resistance and iii) EcN’s lipopolysaccharide (LPS) inactivates T4 phages and notably, treatment with the antibiotic polymyxin B which neutralizes the LPS destroyed the phage inactivation ability of isolated LPS from EcN. Our results further indicate that N-acetylglucosamine at the distal end of O6 antigen in EcN’s LPS could be the interacting partner with T4 phages. From our findings, we have reported for the first time, the role of EcN’s K5 capsule and LPS in its defense against T4 phages. In addition, by inactivating the T4 phages, EcN also protects E. coli K-12 strains from phage infection in tri-culture experiments. The combination of the identified properties is not found in other tested commensal E. coli strains. Furthermore, our research highlights phage resistance as an additional safety feature of EcN, a clinically successful probiotic E. coli strain.
2019-08-27 | GSE135946 | GEO