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.
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Showing 1 to 20 of 40 for “"O-Antigen"”.
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Host-virus interactions in Salmonella O-antigen biosynthesis
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biology, 1967
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Assembly of the O Antigen in the Highly Pathogenic Escherichia Coli Serotype O104:H4
… involved in the assembly of the outer O antigenic polysaccharides of the ECO104 LPS. The O antigen repeating unit of ECO104 has the structure [4-Galα1-4Neu5,7,9Ac3α2-3Galβ1-3GalNAcβ1-]n, which contains a mimic of the human sialyl-T-antigen found on certain types of cancer cells. Each …
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The Effect of O Antigen Loss on the Protein Composition and Inflammatory Response Elicited by Klebsiella pneumoniae
… lumen. K. pneumoniae is often found to lack an O antigen. The absence of the O antigen has been reported to alter the protein content of the membrane which may further alter the immune response elicited by K. pneumoniae. Therefore the purpose of this study was to analyze the protein content and …
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O antigen biosynthesis in Gram-negative bacteria: Characterization of alpha1,4-glucosyltransferase WclY from Escherichia coli O117 and development of glycosyltransferase inhibitors.
… bacteria have a polysaccharide coat (O antigen) consisting of repeating units of oligosaccharides that is assembled by glycosyltransferases. Many of these bacteria are associated with disease, and the polysaccharides are functionally important for immune responses. In light of increasing …
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Investigating the effect of mutations in lipopolysaccharides (LPS) (O-antigen and Core region) of Salmonella Typhimurium on the colonisation of “microgreens”
… of rhubarb chard, Swiss chard, and celery. O-antigen mutant strains SGSC225 and SGSC389 exhibited colonization patterns similar to the wild-type. This suggests that the O-antigen is not essential for bacterial proliferation or suppression of plant immune responses. In contrast, the SGSC230 …
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Modelling and validation of bacterial O-antigen conformations: ring puckering in Shigella flexneri 7a and 7b O-antigens as a case study
… conformation and dynamics of Shigella flexneri O-antigens. S. flexneri is a leading cause of diarrhoeal related diseases, especially in Sub-Saharan Africa and Southeast Asia. There are over 30 S. flexneri serotypes and, with the exception of serotype 6, all share a common O-antigen backbone …
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Towards the Synthesis of the Unusual Monosaccharides Found in the Shigella sonnei O-Antigen and Analysis of Shigella flexneri 2a Glycoconjugate Vaccine Samples
… available. Bioconjugate vaccines based on the O-antigen against various Shigella serotypes are under development. Shigella sonnei and Shigella flexneri 2a are the most prevalent serotypes in industrialised and developed countries respectively and is the subject of this study. This project …
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The role of wzz genes in Salmonella typhimurium virulence.
… core, and a polymer of O units known as O antigen. Wzz proteins control the length of O antigen by an unknown mechanism. While O antigen is essential for S. typhimurium virulence, the significance of length regulation by Wzz is not known. This study investigates the pathogenic relevance of …
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Charakterisierung von spontan phagenresistenten Vibrio cholerae O1 El Tor Mutanten
… Lipopolysaccharid (LPS) ergaben, daß das O-Antigen der Serogruppe O1 den Phagenrezeptor darstellt. Zusätzlich wurden phagenresistente Mutanten des transluzenten O1 El Tor Inaba Stammes P27459 nach Inkubation mit einem lytischen K139-Derivat isoliert. Analysen des LPS-Laufverhaltens in …
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Design of a high-affinity carbohydrate binding protein
… an das aus Kohlenhydraten-bestehende O-Antigen des Lipopolysaccharids von Gram-negativen Bakterien. Das tailspike protein spaltet das O-Antigen um den Bakteriophage an die Oberfläche des Bakteriums zu führen, damit eine Infektion stattfinden kann. Die Affinität des tailspike proteins zum …
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Biophysical chemistry of lipopolysaccharide specific bacteriophages
… repetitive carbohydrate structures of O antigen in its host´s outer membrane lipopolysaccharide molecule. This is mediated by tailspikes, mainly β helical appendages on phage P22 short non contractile tail apparatus (podovirus). The O antigen of all three Salmonella enterica hosts is …
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Surface Polysaccharides of Francisella tularensis: Further Characterization, Role in Virulence, and Application to Novel Vaccine Strategies
… aims to further characterize outer surface antigens of F. tularensis subspecies in regards to virulence, biofilm formation, and role in vaccine development. In addition, this dissertation will also investigate the use of a novel vaccine delivery vehicle, alginate microencapsulation, in …
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Charakterisierung der Lipopolysaccharid-Bindungseigenschaften von Adhäsionsproteinen aus Salmonella-Bakteriophagen
… Kohlenhydrate auf bakteriellen Oberflächen (O-Antigen) erkennen. Das Tailspike-Protein (TSP), das in dieser Arbeit betrachtet wurde, stammt aus dem Bakteriophagen 9NA (9NATSP). 9NATSP weist eine hohe strukturelle Homologie zum gut charakterisierten TSP des Phagen P22 (P22TSP) auf, bei einer …
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Bedeutung der Lipopolysaccharidstrukturen bei pathogenen Vibrio cholerae Stämmen für die Ausbildung von Cholera und Abgrenzung zu Umweltisolaten
… zum jeweiligen Wildtyp (Wt) konnte für eine O Antigen-Mutante von O1 eine Reduktion um 85%, für eine O Antigen/ Kapsel-Mutante von O139 eine Reduktion um 70% in der Adhäsionsrate festgestellt werden. Ein Beitrag von ToxR regulierten Genprodukten ist ebenfalls möglich. Weiterhin wurden mit WavJ …
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The Role of the Extracellular Matrix components of Salmonella enterica serovar Typhimurium Biofilms in Biofilm Formation and Architecture via in vitro analysis
… is composed of curli, cellulose, BapA, O-antigen capsule, colanic acid and extracellular DNA (eDNA) and protects the resident bacteria from diverse environmental stresses such as antibiotics and the host immune response. Studies have shown that curli, which accounts for 85% of the …
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Differential Interactions of Lipopolysaccharides with Lipid Bilayers: Applications for Pathogen Detection
… of amphiphilic lipopolysaccharide (LPS) antigens, so as to improve screening methodologies for food-safety applications, and detection of amphiphiles in general. LPS is associated with the outer membrane of Gram-negative bacteria, and is a primary virulence biomarker of several pathogens. …
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Pseudomonas aeruginosa Type IV pilus and resistance to the antimicrobial properties of surfactant protein-A
… we also have shown that Tfp glycosylation with O-antigen subunits allows for increased resistance to SP-A. We have also shown the glycosyltransferase mutant, 1244G7, which is deficient in O-antigen, is more susceptible to SP-A-mediated lung clearance and phagocytosis, but not membrane …
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Bacterial Manipulation of Actin Dynamics via p21 Activated Kinases and Cofilin
… flexneri comet tail formation. Shigella LPS O-antigen null mutants have been previously shown to have poor comet tail formation, however the mechanism behind this defect remains controversial. Previous studies have focused on the relationship between LPS length and the functionality of IcsA, …
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MOL-PCR For SNP Based Detection and Characterization of STEC non-O157 Strains
… (SNPs) have been identified in the O-antigen gene cluster for each of the non-O157 STEC serogroups that can differentiate between a STEC and non-STEC strain. In this study, the multiplex oligonucleotide ligation-PCR (MOL-PCR) detection platform was adapted for the detection and …
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Characterization of novel virulence factors of Shigella flexneri and development of Caenorhabditis elegans as an animal model for Shigella infection
… virulence. To date in S. flexneri, the O-antigen modifying genes are the only bacteriophage genes that have been linked to host virulence. Here the S. flexneri phage SfII was isolated from a highly prevalent S. flexneri serotype 2a strain and completely sequenced to identify novel …
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