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Concept

Fertility factor (bacteria)

Related publications (28)

Molecular mechanism of plasmid elimination by the DdmDE defense system

Melanie Blokesch, Sandrine Stutzmann, David William Adams, Laurie Righi

Seventh pandemic Vibrio cholerae strains contain two pathogenicity islands that encode the DNA defense modules DdmABC and DdmDE. Here we use cryogenic electron microscopy to reveal the mechanistic basis for plasmid defense by DdmDE. A structure of the DdmD ...

American Association for the Advancement of Science2024

How Vibrio cholerae adapts to the environment: from cell shape transitions to antagonistic behavior

Leonardo Filipe Lemos Rocha

The bacterium Vibrio cholerae is the causative agent of the diarrheal disease cholera, which affects millions of people every year. Apart from being a human pathogen, V. cholerae is also a common member of aquatic habitats. Whilst the mechanism that allow ...

EPFL2022

Two defence systems eliminate plasmids from seventh pandemic Vibrio cholerae

Melanie Blokesch, David William Adams, Milena Jadwiga Jaskolska

Horizontal gene transfer can trigger rapid shifts in bacterial evolution. Driven by a variety of mobile genetic elements—in particular bacteriophages and plasmids—the ability to share genes within and across species underpins the exceptional adaptability o ...

2022

Natural competence of the pathogen Acinetobacter baumannii: an elusive phenomenon

Nina Vesel

Natural competence for transformation is an important driver of horizontal DNA exchange between different organisms. This can result in accumulation of dangerous genetic features, such as antibiotic resistance genes, in a single organism. One example of an ...

EPFL2022

Vancomycin resistance plasmids affect persistence of Enterococcus faecium in water

Suzanne Marie Young

Vancomycin resistant enterococci (VRE) cause 20,000 infections annually in the United States, most of which are nosocomial. Recent findings of VRE in sewage-contaminated surface waters demonstrate an alternate route of human exposure, and a possible settin ...

PERGAMON-ELSEVIER SCIENCE LTD2019

The type IV pilus protein PilU functions as a PilT-dependent retraction ATPase

Melanie Blokesch, Sandrine Stutzmann, Candice Stoudmann, David William Adams, Jorge André Matias Pereira

Type IV pili are dynamic cell surface appendages found throughout the bacteria. The ability of these structures to undergo repetitive cycles of extension and retraction underpins their crucial roles in adhesion, motility and natural competence for transfor ...

2019

Effects of physiological self-crowding of DNA on shape and biological properties of DNA molecules with various levels of supercoiling

Giovanni Dietler, Yannis Burnier, Julien Dorier, Fabrizio Benedetti, Aleksandre Japaridze

DNA in bacterial chromosomes and bacterial plasmids is supercoiled. DNA supercoiling is essential for DNA replication and gene regulation. However, the density of supercoiling in vivo is circa twice smaller than in deproteinized DNA molecules isolated from ...

Oxford University Press2015

Enhanced Plasmid DNA Utilization in Transiently Transfected CHO-DG44 Cells in the Presence of Polar Solvents

Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Yashas Rajendra, Divor Kiseljak, Sowmya Balasubramanian

Although the protein yields from transient gene expression (TGE) with Chinese hamster ovary (CHO) cells have recently improved, the amount of plasmid DNA (pDNA) needed for transfection remains relatively high. We describe a strategy to reduce the pDNA amou ...

American Chemical Society2015

Transcriptional and post-transcriptional limitations of high-yielding, PEI-mediated transient transfection with CHO and HEK-293E cells

Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Yashas Rajendra, Divor Kiseljak

Transient gene expression (TGE) in human embryonic kidney (HEK-293) and Chinese hamster ovary (CHO) cells is a well-established technology for the rapid generation of recombinant proteins. Although the maximum TGE yields have reached 1 g/L or more, the amo ...

American Chemical Society2015

Study of transposon-mediated cell pool and cell line generation in CHO cells

Sowmya Balasubramanian

The goal of this thesis was to evaluate the use of artificial transposon systems for the generation of recombinant cell pools and cell lines with Chinese hamster ovary (CHO) cells as the production host. Transposons are naturally occurring genetic elements ...

EPFL2015

Virus-free transient protein production in Sf9 cells

Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Xiao Shen

A method for virus-free transient gene expression from suspension-adapted Sf9 insect cells was developed with the gene of interest being expressed from a plasmid carrying the homologous region 5 enhancer (hr5) and the immediate early 1 (ie1) promoter from ...

Elsevier2014

Mathematical models and computational methods for the analysis of genome-scale protein synthesis

Julien Racle

Proteins are a ubiquitous and indispensable element for every living organism, from simple bacteria to mammals. Already in the simplest organisms, there exist some thousands of different protein species that take up a great variety of structures, and thus ...

EPFL2014

Poly(ethyleneimine)-Mediated Large-Scale Transient Gene Expression: Influence of Molecular Weight, Polydispersity and N-Propionyl Groups

Harm-Anton Klok, Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Zuzana Kadlecova

Three synthesis lots of linear poly(ethyleneimine) (PEI) are compared to a fully hydrolyzed linear PEI (commercially available as PEI Max) regarding structure, polyplex formation with plasmid DNA, and transfection of suspension-adapted HEK-293E cells. PEI ...

Wiley-Blackwell2012

TransFLP - A Method to Genetically Modify Vibrio cholerae Based on Natural Transformation and FLP-recombination

Melanie Blokesch

Several methods are available to manipulate bacterial chromosomes(1-3). Most of these protocols rely on the insertion of conditionally replicative plasmids (e.g. harboring pir-dependent or temperature-sensitive replicons(1,2)). These plasmids are integrate ...

2012

Role of non-specific DNA in reducing coding DNA requirement for transient gene expression with CHO and HEK-293E cells

Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Yashas Rajendra, Divor Kiseljak

Transient gene expression (TGE) is a rapid method for the production of recombinant proteins in mammalian cells. While the TGE volumetric productivity has improved significantly over the past decade, the amount of plasmid DNA (pDNA) needed for transfection ...

2012

A simple high-yielding process for transient gene expression in CHO cells

Florian Maria Wurm, David Hacker, Lucia Baldi Unser, Yashas Rajendra, Divor Kiseljak

Here we describe a simplified method for transient gene expression (TGE) in suspension-adapted Chinese hamster ovary (CHO) cells using polyethylenimine (PEI) for DNA delivery. Both the transfection and production phases of the bioprocess were performed at ...

Elsevier2011

Gene Delivery with Hyperbranched Polylysine

Zuzana Kadlecova

The delivery of exogenous nucleic acids into mammalian cells is a valuable technique for basic research studies on the expression, regulation and function of genes and proteins. At the same time, gene delivery to cultivated mammalian cells has become funda ...

EPFL2011

Transient Gene Expression in HEK-293E Cells for Recombinant Protein Production : Process Characterization towards GMP Approval

The growing demand of biopharmaceutical products is boosting the market for therapeutic recombinant proteins (r-proteins). More than half of the 140 r-proteins that have gained approval for human therapeutic use are manufactured in mammalian cells that mak ...

EPFL2010

Transient recombinant protein expression in mammalian cells : the role of mRNA level and stability

Sarah Wulhfard

Transient gene expression (TGE) is a rapid method for generating recombinant proteins in mammalian cells, but the volumetric productivities for secreted proteins in transiently transfected CHO DG44 cells are typically more than an order of magnitude lower ...

EPFL2009

Calcium phosphate transfection generates mammalian recombinant cell lines with higher specific productivity than polyfection

Florian Maria Wurm, David Hacker, Madiha Derouazi, Sébastien Chenuet

Transfection with polyethylenimine (PEI) was evaluated as a method for the generation of recombinant Chinese hamster ovary (CHO DG44) cell lines by direct comparison with calcium phosphate-DNA coprecipitation (CaPO4) using both green fluorescent protein (G ...

2008