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 15 of 15 for “"Autoinducer 2"”.
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Autoinducer-2-based quorum sensing of foodborne pathogenic bacteria under food related conditions
… studies was to evaluate potential involvement of autoinducer (AI)-2-based quorum sensing (quorum sensing: cell density dependent cell-to-cell signaling) of foodborne pathogenic bacteria in food environments. Under the conditions of these studies, AI-2 activity of Salmonella and Escherichia coli …
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Biochemical Assay Optimization and Computational Screening Efforts to Identify Potential LuxS Inhibitors
… QS is regulated by the small signaling molecule autoinducer-2 (AI-2) and is implicated in the infectious behaviors of various bacterial species. AI-2 is biosynthesized from <em>S-</em>ribosylhomocysteine (SRH) by the enzyme LuxS and induces interspecies cell-to-cell communication. Inhibition of …
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Intercellular communication in uropathogenic Escherichia coli and the probiotic Lactobacillus reuter
… This study sought to characterize the role of autoinducer 2 (AI-2) in the regulation of virulence factors of uropathogenic Escherichia coli J96, determine if the probiotic Lactobacillus reuteri RC-14 produced AI-2, and evaluate if secreted products from the probiotic could affect pathogen …
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Mutant analysis of luminescence and autoinduction in a marine bacterium
… is mediated by a signal molecule called the "autoinducer". The mechanistic bases of both luminescence and autoinduction are well known in V. fischeri, but this knowledge is mostly derived from studies of the cloned luminescence and autoinduction genes expressed in Escherichia coli. In this …
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Survival and recovery of Escherichia coli O157:H7 during starvation at sub-optimal temperatures
… on agar. The role of quorum sensing (LuxS/autoinducer-2) on starved cell recovery was investigated by supplementing PCA with quorum sensing molecules and using a mutant strain deficient in luxS, a gene encoding the synthase of autoinducer-2. The ability of starved and non-starved cells to …
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Synthesis of S-Ribosyl-L-homocysteine and Analogs Modified at the Homocysteine-C3 Position
… (DPD), which is the precursor of autoinducer-2 (AI-2). Thus, inhibitors of LuxS could prevent QS by halting the conversion of SRH to AI-2 rendering the cell “uncommunicative”. This work shows the successful chemical synthesis of SRH and progress towards the synthesis of SRH analogs …
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HAEMOPHILUS INFLUENZAE AND MORAXELLA CATARRHALIS INTRA- AND INTERSPECIES QUORUM SIGNALING
… is bacterial communication via quorum signaling. Autoinducer-2 (AI-2) is termed an interspecies signal as the genetic determinant for AI-2 production (<italic>luxS</italic>) is highly conserved and many species possess the machinery to respond to AI-2. <italic>H. influenzae</italic> has a …
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New Sensing Modalities for Bacterial and Environmental Phenomena
… molecules: the universal quorum sensing molecule autoinducer-2 (AI-2), the species-specific Pseudomonas Quinolone Signal (PQS), and the stationary phase indicator molecule indole. SERS substrates were formed by galvanic displacement, a substrate fabrication method that can be adapted to many SERS …
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Chemical Processes That Govern the Natural Attenuation of Microbial Signals: Environments That Simulate Photosynthetic Biofilms
… (DPD) derivatives functionally classified as autoinducer-2 (AI2). Oxidative attenuation of the acylhomoserine lactones (AHLs) by hydroxyl radicals results in the formation of keto- and hydroxo AHLs, some of which are more potent signals (per mole) than the original AHLs. In contrast, parallel …
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The Functional Characterization of the Quorum Sensing E. Coli Regulators B and C in EHEC
… of QseC is not affected by the addition of autoinducer-2 or intestinal hormones, including gastrin, galanin, and secretin. Additionally, autophosphorylation can be antagonized upon the addition of phentolamine, an a-adrenergic receptor antagonist. Given that enterocytes harbor a-adrenergic …
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Novel Virulence Factors in the Pathogenesis of Yersinia pestis Infection, the Causative Agent of Plague
… inter-bacterial signaling system mediated by autoinducer-2 (AI-2) quorum-sensing molecule. Deletion of the gene encoding the synthetic enzyme for AI-2 substrate, luxS, leads to either no change or, paradoxically, an increase in in vivo bacterial virulence. Deletion of rbsA and lsrA genes, ABC …
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ALTERING THE AI-2 MEDIATED QUORUM SENSING CIRCUITRY TO QUENCH BACTERIAL COMMUNICATION NETWORKS
… by targeting the interspecies signaling molecule autoinducer-2 (AI-2), which is produced or recognized by over 70 species of bacteria. Our first approach is to bring the native intracellular AI-2 signal processing mechanisms to the extracellular surroundings to quench the QS response of bacteria. …
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Identification of Quorum Sensing Genes in Hypersaline Microbial Mats
… diffusible signaling molecules referred to as autoinducers. This pathway ultimately coordinates gene expression among the bacterial community leading to synchronized behaviors in a multicellular fashion. Quorum sensing is known to be controlled by synthases of autoinducers and transcriptional …
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PATTERNED BIOFILM FORMATION TO INVESTIGATE BACTERIA-SURFACE INTERACTIONS
… gene on a plasmid and by adding the precursor of autoinducer-2 (AI-2) signal in the culture. These results suggest that AI-2 mediated quorum sensing and motility are involved in the interaction among cell clusters. Based on these findings, a model was proposed to explain the intrinsic …
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Investigating galactose metabolism in Streptococcus pneumoniae
… demonstrating that the quorum sensing molecule Autoinducer 2 (AI-2) is likely phosphorylated during import into the cell. Phosphorylated AI-2 is then proposed to either directly or indirectly phosphorylate GalR, the regulator of the Leloir pathway, driving an increase in galactose metabolism and …