Search results for "Erich"
showing 10 items of 805 documents
Gut microbiota imbalance and colorectal cancer
2016
International audience; The gut microbiota acts as a real organ. The symbiotic interactions between resident micro-organisms and the digestive tract highly contribute to maintain the gut homeostasis. However, alterations to the microbiome caused by environmental changes (e.g., infection, diet and/or lifestyle) can disturb this symbiotic relationship and promote disease, such as inflammatory bowel diseases and cancer. Colorectal cancer is a complex association of tumoral cells, non-neoplastic cells and a large amount of micro-organisms, and the involvement of the microbiota in colorectal carcinogenesis is becoming increasingly clear. Indeed, many changes in the bacterial composition of the g…
[How some commensal bacteria would exacerbate colorectal carcinogenesis?].
2016
International audience; The gut microbiota maintains a relationship with its host with strong mutual benefits. Changes in the composition of the intestinal microbiota have been detected in colorectal cancer patients to the extent that it is now considered as a real contributing factor in this pathology. In this review, we focus on three commensal bacterial species, namely Bacteroides fragilis, Fusobacterium nucleatum, and Escherichia coli, which seem to emerge as pathogens and to contribute to colorectal carcinogenesis through their inflammatory and oncogenic properties.; Le microbiote intestinal entretient une relation mutualiste forte avec l’hôte. Depuis la mise en évidence de modificatio…
EFMviz
2020
Elementary Flux Modes (EFMs) are a tool for constraint-based modeling and metabolic network analysis. However, systematic and automated visualization of EFMs, capable of integrating various data types is still a challenge. In this study, we developed an extension for the widely adopted COBRA Toolbox, EFMviz, for analysis and graphical visualization of EFMs as networks of reactions, metabolites and genes. The analysis workflow offers a platform for EFM visualization to improve EFM interpretability by connecting COBRA toolbox with the network analysis and visualization software Cytoscape. The biological applicability of EFMviz is demonstrated in two use cases on medium (Escherichia coli, iAF1…
Liquid chromatography-ultraviolet detection and quantification of heat-labile toxin produced by enterotoxigenic E. coli cultured under different cond…
2017
Abstract Enterotoxigenic Escherichia coli (ETEC) is the main bacterial cause of dehydrating infant diarrhoea in less-developed countries. Labile toxin (LT) is the major virulent factor of ETEC. Easy diagnostic tests are necessary to reduce the number of cases. Immunological methods have some drawbacks and also have important limitations. For that reason, a Liquid Chromatography coupled to UV detector technique (LC-UV) has been optimize to a rapid identification and quantification of LT from bacteria cultures. It is also important to know optimal conditions for LT and with this purpose several enterotoxigenic E. coli strains have been studied to determine the influence of glucose concentrati…
Expanding the toolbox for Synechocystis sp. PCC 6803 : validation of replicative vectors and characterization of a novel set of promoters
2018
Cyanobacteria are promising ‘low-cost’ cell factories since they have minimal nutritional requirements, high metabolic plasticity and can use sunlight and CO2 as energy and carbon sources. The unicellular Synechocystis sp. PCC 6803, already considered the ‘green’ Escherichia coli, is the best studied cyanobacterium but to be used as an efficient and robust photoautotrophic chassis it requires a customized and well-characterized toolbox. In this context, we evaluated the possibility of using three self-replicative vectors from the Standard European Vector Architecture (SEVA) repository to transform Synechocystis. Our results demonstrated that the presence of the plasmid does not lead to an e…
Transmembrane signaling and cytoplasmic signal conversion by dimeric transmembrane helix 2 and a linker domain of the DcuS sensor kinase
2020
Transmembrane (TM) signaling is a key process of membrane-bound sensor kinases. The C4-dicarboxylate (fumarate) responsive sensor kinase DcuS of Escherichia coli is anchored by TM helices TM1 and TM2 in the membrane. Signal transmission across the membrane relies on the piston-type movement of the periplasmic part of TM2. To define the role of TM2 in TM signaling, we use oxidative Cys cross-linking to demonstrate that TM2 extends over the full distance of the membrane and forms a stable TM homodimer in both the inactive and fumarate-activated state of DcuS. An S186xxxGxxxG194 motif is required for the stability and function of the TM2 homodimer. The TM2 helix further extends on the periplas…
Plasmonic Nanosensors for the Determination of Drug Effectiveness on Membrane Receptors.
2016
We demonstrate the potential of the NanoSPR (nanoscale surface plasmon resonance sensors) method as a simple and cheap tool for the quantitative study of membrane protein–protein interactions. We use NanoSPR to determine the effectiveness of two potential drug candidates that inhibit the protein complex formation between FtsA and ZipA at initial stages of bacterial division. As the NanoSPR method relies on individual gold nanorods as sensing elements, there is no need for fluorescent labels or organic cosolvents, and it provides intrinsically high statistics. NanoSPR could become a powerful tool in drug development, drug delivery, and membrane studies.
Comparison of hemolytic activity of the intermediate subunit of Entamoeba histolytica and Entamoeba dispar lectins.
2017
Galactose and N-acetyl-D-galactosamine-inhibitable lectin of Entamoeba histolytica has roles in pathogenicity and induction of protective immunity in rodent models of amoebiasis. Recently, the intermediate subunit of the lectin, Igl1, of E. histolytica has been shown to have hemolytic activity. However, the corresponding lectin is also expressed in a non-virulent species, Entamoeba dispar, and another subunit, Igl2, is expressed in the protozoa. Therefore, in this study, we compared the activities of Igl1 and Igl2 subunits from E. histolytica and E. dispar using various regions of recombinant Igl proteins expressed in Escherichia coli. The recombinant E. dispar Igl proteins had comparable h…
Extraintestinal pathogenic Escherichia coli sequence type 131 H30-R and H30-Rx subclones in retail chicken meat, Italy
2016
Extraintestinal pathogenic Escherichia coli sequence type 131 (ST131), typically fluoroquinolone-resistant (FQ-R) and/or extended-spectrum β-lactamase (ESBL)-producing, has emerged globally. Among clinical isolates, ST131, primarily its H30-R and H30-Rx subclones, accounts for most antimicrobial-resistant E. coli and is the dominant E. coli strain worldwide. We assessed its prevalence and characteristics among raw chicken meat samples on sale in Palermo, Italy. A collection of 237 fluoroquinolone resistant and ESBL/AmpC producing E. coli isolates, which had been isolated from processed retail chicken meat in the period May 2013-April 2015, was analyzed. Established polymerase chain reaction…
Conjugative ESBL plasmids differ in their potential to rescue susceptible bacteria via horizontal gene transfer in lethal antibiotic concentrations.
2017
Conjugative ESBL plasmids differ in their potential to rescue susceptible bacteria via horizontal gene transfer in lethal antibiotic concentrations