Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 19 of 19 for “"Type IV Pili"”.
-
Type IV Pili-Dependent Secretion of Biofilm Matrix Material Proteins in Clostridium perfringens
Clostridium perfringens is a Gram-positive bacterium that secretes a biofilm matrix material. The goal of these experiments was to identify pilin mutants that are needed for secretion of the biofilm matrix and develop a functional model for a type II secretion system (T2SS) in C. perfringens. …
-
Use of an Inducible Promoter to Characterize Type IV Pili Homologues in Clostridium perfringens
… of <i>Clostridium perfringens</i>, a Gram-positive anaerobic pathogen, were lacking a tightlyregulated, inducible promoter system in their genetic toolbox. We constructed a lactose-inducible plasmid-based system utilizing the transcriptional regulator, BgaR. Using the <i>E. coli</i> reporter …
-
Spectroscopic Studies of Abiotic and Biological Nanomaterials: Silver Nanoparticles, Rhodamine 6G Adsorbed on Graphene, and c-Type Cytochromes and Type IV Pili in Geobacter sulfurreducens
… rhodamine 6G adsorbed on graphene, and the type IV pili and c-type cytochromes produced by the dissimilatory metal-reducing bacterium Geobacter sulfurreducens. Although these systems are quite different in some ways, they can all be considered examples of nanomaterials. A nanomaterial is …
-
Elucidating Pseudomonas aeruginosa virulence gene regulation by the ribbon-helix-helix transcription factor AmrZ
… alginate biosynthesis, flagellum expression, and type IV pili localization and twitching motility. AmrZ also acts as an autorepressor by binding two sites on its own promoter.
-
Molecular Analysis of Type IV Pilus Assembly in Clostridium perfringens
Clostridium perfringens is a Gram-positive anaerobe capable of causing disease in humans and many animals. C. perfringens is able to move across surfaces in a manner that is dependent on growth and type IV pili. Type IV pili are filaments that can be extended away from the cell by rapid …
-
Molecular Investigations of Protein Assemblies Involved in Prokaryotic Virulence
Protein complexes mediate a diverse range of behavior in prokaryotic cells, yet the exact molecular mechanisms explaining how many of these complexes assemble and function remain unknown. This work focuses on understanding the molecular mechanisms of two different protein assemblies responsible for …
-
CRISPR3 Regulates Exopolysaccharide Production in Myxococcus xanthus
… a model organism for studying development and Type IV pili (T4P), harbors three Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) on its chromosome. CRISPR systems, which function as an adaptive immune system in prokaryotes, are classified into three types based on …
-
Shear force impacts type IV pilus and flagellar dynamics during Pseudomonas aeruginosa surface adhesion
… I examine how Pseudomonas aeruginosa cells use type IV pili to interact with surfaces under host-relevant shear forces. I demonstrate that cell tilting, driven by type IV pilus retraction, predicts surface departure at low shear forces. Conversely, higher host-relevant shear forces counteract …
-
SPECIFIC RESIDUES WITHIN PSEUDOMONAS AERUGINOSA AmrZ ARE REQUIRED FOR TRANSCRIPTIONAL REGULATION OF VIRULENCE FACTORS CONTRIBUTING TO INFECTION
… modes provides a strong advantage for survival. AmrZ is a ribbon-helix-helix transcriptional regulator that controls several virulence factors—alginate production, type IV pili expression and twitching motility, and flagellar expression. AmrZ acts as both an activator and a repressor, …
-
Investigating the Roles of the Stk Locus in Development, Motility and Exopolysaccharide Production in Myxococcus Xanthus
Myxococcus xanthus, a Gram-negative bacterium with a developmental cycle, displays a type IV pili (TFP) mediated surface motility known as social (S) gliding. Beside the polarly localized TFP, the fibril or extracellular polysaccharide (EPS) is also required for S-motility to function. It is …
-
Localization of Type IV Pilin Polymerization Proteins in Clostridium perfringens
… is a spore-forming anaerobic Gram-positive rod which has gliding motility through type IV Pili (TFP). Since the discovery of TFP in Gram-positive bacteria is relatively new, more studies are required to understand the mechanism and interaction of the proteins of this machinery. Moreover, …
-
A New Class of Antibiotic That Prevents Drug Tolerance, Persistence, and Resistance By Controlling Emergence of Phenotypes.
… stress, bacteria evolve into different phenotypes like hyper motile, hyper adherent and hyper virulent which are tolerant and persistent to antibiotic treatment. The use of antibiotic therapy to combat such resilient bacterial phenotypes is extremely tough. As a result, the scientific …
-
Regulation of Exopolysaccharide Production in Myxococcus Xanthus
… extension and retraction of polarly localized type IV pili (Tfp). Besides Tfp, exopolysaccharides (EPS), another cell surface associated component, are also required for M. xanthus S motility. Previous studies demonstrated that the Dif chemotaxis-like signal transduction pathway is central to …
-
Biosynthesis of Nucleotide Sugar Monomers for Exopolysaccharide Production in Myxococcus Xanthus
… S motility requires two cellular structures: type IV pili (TFP) and exopolysaccharides (EPS). Previous studies have shown that M. xanthus does not use glucose or any other sugar as a primary carbon source. However, eight monosaccharides, namely glucose, mannose, arabinose, galactose, xylose, …
-
Chemical Control and Understanding of Horizontal Gene Transfers, Drug-Resistance Development, and Filament and Biofilm Formation
… faster than without antibiotics, what phenotypes of bacteria form in an antibiotic-promoted biofilm, and what different biofilm compositions and structures are caused by the presence of antibiotics. Among other effects, antibiotics can cause bacteria to form filaments of living bacteria. …
-
Characterization of Type IV Pilus System Genes and Their Regulation in Clostridium perfringens
Clostridium perfringens is a Gram-positive (Gr+) anaerobic pathogen that was found to contain Type IV pilus (T4P) system genes within the genomes of all its sequenced strains. T4P are widely used in Gram-negative organisms for aggregation, biofilm formation, adherence, and DNA uptake. Because few …
-
The Type IV Pilus Assembly ATPase PilB as a Regulator of Biofilm Formation and an Antivirulence Target
Bacterial type IV pili (T4P) are filamentous surface appendages with a variety of functions including motility, surface attachment, and biofilm formation. In many species of bacteria a clear understanding of how the functions of T4P in lifestyle switching are regulated remains to be elucidated. …
-
Novel applications of advanced optical microscopy for microbiology
… To overcome this a novel variant of the livecell label-free technique, interference reflection microscopy (IRM), was developed. This method relies on the interference of multiple wavelengths of incident and reflected light and results in a series of intensity maxima and minima which encode …
-
Déterminants moléculaires de la spécificité du transfert conjugatif du plasmide TP114 dans le microbiote
… propriétés. Le développement de microorganismes vivants capables d’effectuer des tâches de hautes précisions, robustes et prédictibles semble très prometteur pour diverses applications en biotechnologie, en médecine, en agriculture et en environnement. Ces approches sont d’un grand intérêt dans le …