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Articles 1 - 11 of 11
Full-Text Articles in Life Sciences
Investigating Oxidative Stress And Large-Scale Genomic Reduction In Vibrio Natriegens Through The Development And Application Of New Genetic Techniques, Elizabeth Glasgo
Investigating Oxidative Stress And Large-Scale Genomic Reduction In Vibrio Natriegens Through The Development And Application Of New Genetic Techniques, Elizabeth Glasgo
Doctoral Dissertations
Vibrio natriegens is the fastest replicating bacterium and recent work has demonstrated its potential for biotechnology and synthetic biology applications. While these industries have been the focus of V. natriegens research, it offers a promising system for diverse laboratory studies. However, currently a complete understanding of V. natriegens biology is lacking. As such, there is a need to advance genetic techniques and physiological understanding to better inform all aforementioned applications. Here we describe our contributions to the growing field of V. natriegens genetics and the application of these new techniques to study physiological processes and themes in genome evolution. Briefly, …
The Response Of Microcystis And The Microbiome To Exogenous Hydrogen Peroxide, Bryan A. Puma
The Response Of Microcystis And The Microbiome To Exogenous Hydrogen Peroxide, Bryan A. Puma
Masters Theses, 2020-current
Microcystis spp. produce prolific annual blooms in freshwater systems worldwide. The success of these blooms depends heavily on the Microcystis spp. overcoming environmental factors such as oxidative stress caused by reactive oxygen species (ROS) like hydrogen peroxide. Most Microcystis genomes do not contain many genes for responding to oxidative stress, including those that encode the enzyme catalase. Other cyanobacteria such as Prochlorococcus that also lack hydrogen peroxide degrading enzymes have been shown to benefit from partnerships with heterotrophic bacteria. Microcystis spp. may also receive similar benefits from heterotrophic bacteria in the phycosphere. To test this hypothesis, we examined the …
An Antimicrobial Polydopamine Surface Coating To Reduce Biofouling On Telemetry Tags Used In Marine Conservation Practices, Ariana Smies
An Antimicrobial Polydopamine Surface Coating To Reduce Biofouling On Telemetry Tags Used In Marine Conservation Practices, Ariana Smies
Dissertations, Master's Theses and Master's Reports
Satellite telemetry tags are used to track the migration patterns of large cetaceans. These tags penetrate the dermis and remain embedded in the underlying blubber tissue. As the dermis of cetaceans is host to a diverse microbiome, and it is impossible to clean the skin before implanting the devices, the potential for infection is increased when the tags penetrate through the skin. H2O2 is a potential antimicrobial agent that, in addition to showing broad-spectrum efficacy against gram-negative and gram-positive bacteria, can promote wound healing outcomes by promoting proliferative factors and peptides that protect against oxidative stress. However, …
Determining The Ecological And Physiological Factors Contributing To The Competitive Success Of Prochlorococcus In The Oligotrophic Ocean, Benjamin C. Calfee
Determining The Ecological And Physiological Factors Contributing To The Competitive Success Of Prochlorococcus In The Oligotrophic Ocean, Benjamin C. Calfee
Doctoral Dissertations
Prochlorococcus is a genus of extremely successful marine cyanobacteria. This success is realized through its pervasive biogeographical range and presence in almost all open ocean environments where it usually it the dominant phytoplankton. Limited capabilities of culturing and genetic manipulation of this organism have resulted in assumptions about this success overwhelmingly based on field observations. These studies have assumed adaptations for resource uptake and utilization in nutrient limited environments to cause dominance of Prochlorococcus over other photosynthetic microbes. In an attempt to definitively explain this through laboratory culture, we developed a culturing system to assay questions of nutrient limitation effects …
The Impact Of Oxygen Availability And Oxidative Stress On Regulation Of Cyclic-Dimeric-Gmp In Listeria Monocytogenes Strain F2365, Anna G. Welch
The Impact Of Oxygen Availability And Oxidative Stress On Regulation Of Cyclic-Dimeric-Gmp In Listeria Monocytogenes Strain F2365, Anna G. Welch
Honors Theses
Listeria monocytogenes is a gram-positive foodborne pathogen that results in the infectious disease listeriosis. The second messenger molecule cyclic-dimeric-GMP has been found to be responsible for the regulation of expression of many of its virulence factors with diguanylate cyclases and phosphodiesterases regulating the intracellular concentration of cyclic-di-GMP through synthesis and degradation, respectively. This study investigated the possibility that the availability of oxygen is the environmental signal crucial to the regulation of these enzymes. Prior research in our laboratory has demonstrated that the intracellular concentration of cyclic-di-GMP is elevated when exposed to anaerobic conditions. Due to this, it was hypothesized that …
The Antimicrobial Properties Of Honey And Their Effect On Pathogenic Bacteria, Shreena Himanshu Mody
The Antimicrobial Properties Of Honey And Their Effect On Pathogenic Bacteria, Shreena Himanshu Mody
Theses and Dissertations
Honey has been used to heal wounds since ancient times. There are many references in ancient literature that cite honey for its medicinal uses. It is used as an alternative agent to cure infections of wounds, burns, ulcers etc. Researchers have shown some of the antimicrobial properties of honey when used as an ointment. When applied to an affected area, it helps to promote the growth of healthy tissue. One of the factors on which the quality of the honey depends, is its geographical origin. Based on the location, honey types can vary as much as 100-fold from each other …
High Glucose Induces Reactivation Of Latent Kaposi’S Sarcoma-Associated Herpesvirus, Fengchun Ye, Yan Zeng, Jingfeng Sha, Tiffany Jones, Kurt Kuhne, Charles Wood, Shou-Jiang Gao
High Glucose Induces Reactivation Of Latent Kaposi’S Sarcoma-Associated Herpesvirus, Fengchun Ye, Yan Zeng, Jingfeng Sha, Tiffany Jones, Kurt Kuhne, Charles Wood, Shou-Jiang Gao
Nebraska Center for Virology: Faculty Publications
High prevalence of Kaposi’s sarcoma (KS) is seen in diabetic patients. It is unknown if the physiological condition of diabetes contributes to KS development. We found elevated levels of viral lytic gene expression when Kaposi’s sarcoma-associated herpesvirus (KSHV) infected cells were cultured in high glucose medium. To demonstrate the association between high glucose and KSHV replication, we xeno29
grafted telomerase-immortalized human umbilical vein endothelial cells that are infected with KSHV (TIVE-KSHV) into hyperglycemic and normal nude mice. The injected cells expressed significantly higher levels of KSHV lytic genes in hyperglycemic mice than in normal mice. We further demonstrated that high …
Francisella Tularensis Catalase Restricts Immune Function By Impairing Trpm2 Channel Activity, Nicole Lynn Flaherty
Francisella Tularensis Catalase Restricts Immune Function By Impairing Trpm2 Channel Activity, Nicole Lynn Flaherty
Legacy Theses & Dissertations (2009 - 2024)
As an innate defense mechanism, macrophages produce reactive species that weaken pathogens and serve as secondary messengers to modify signaling responses involved in immune function. The gram-negative bacterium F. tularensis utilizes its antioxidant armature to limit the host immune response but the mechanism behind this suppression has not been defined. Here we establish that F. tularensis limits Ca2+ entry thereby limiting actin reorganization and IL-6 production in a redox-dependent fashion. Wild-type (LVS) or catalase deficient F. tularensis (∆katG) show distinct profiles in their H2O2 scavenging capacity, 1 pM/sec and 0.015 pM/sec, respectively. Murine alveolar macrophages infected with ∆katG display distinct …
Role Of The Pkna And Pknb Kinases In Mycobacterium Tuberculosis, Tripti Anandan
Role Of The Pkna And Pknb Kinases In Mycobacterium Tuberculosis, Tripti Anandan
Wayne State University Dissertations
To respond to environmental changes, M. tuberculosis possesses eleven "eukaryotic-type" Ser/Thr protein kinases. The aim of the study described in this dissertation was to identify role of two of these kinases; PknA and PknB that are essential in M. tuberculosis. Two approaches are described to screen for potential in vivo substrates of PknA/PknB. First approach is based on proteomic search by over-expressing PknA/PknB in M. tuberculosis. Proteomic search led to identification of proteasome to be a substrate of PknA and PknB in M. tuberculosis. Furthermore, I demonstrate that the phosphorylation of PrcA and PrcB by PknA regulates processing of Pre-PrcB. …
Farnesol Induces Hydrogen Peroxide Resistance In Candida Albicans Yeast By Inhibiting The Ras-Cyclic Amp Signaling Pathway, Aurélie Deveau, Amy E. Piispanen, Angelyca A. Jackson, Deborah A. Hogan
Farnesol Induces Hydrogen Peroxide Resistance In Candida Albicans Yeast By Inhibiting The Ras-Cyclic Amp Signaling Pathway, Aurélie Deveau, Amy E. Piispanen, Angelyca A. Jackson, Deborah A. Hogan
Dartmouth Scholarship
Farnesol, a Candida albicans cell-cell signaling molecule that participates in the control of morphology, has an additional role in protection of the fungus against oxidative stress. In this report, we show that although farnesol induces the accumulation of intracellular reactive oxygen species (ROS), ROS generation is not necessary for the induction of catalase (Cat1)-mediated oxidative-stress resistance. Two antioxidants, α-tocopherol and, to a lesser extent, ascorbic acid effectively reduced intracellular ROS generation by farnesol but did not alter farnesol-induced oxidative-stress resistance. Farnesol inhibits the Ras1-adenylate cyclase (Cyr1) signaling pathway to achieve its effects on morphology under hypha-inducing conditions, and we demonstrate …
Genome-Wide Transcriptional Profiling Of The Cyclic Amp-Dependent Signaling Pathway During Morphogenic Transitions Of Candida Albicans, Yong-Sun Bahn, Matthew Molenda, Janet F. Staab, Courtney A. Lyman, Laura J. Gordon, Paula Sundstrom
Genome-Wide Transcriptional Profiling Of The Cyclic Amp-Dependent Signaling Pathway During Morphogenic Transitions Of Candida Albicans, Yong-Sun Bahn, Matthew Molenda, Janet F. Staab, Courtney A. Lyman, Laura J. Gordon, Paula Sundstrom
Dartmouth Scholarship
Candida albicans is an opportunistic human fungal pathogen that causes systemic candidiasis as well as superficial mucosal candidiasis. In response to the host environment, C. albicans transitions between yeast and hyphal forms. In particular, hyphal growth is important in facilitating adhesion and invasion of host tissues, concomitant with the expression of various hypha-specific virulence factors. In previous work, we showed that the cyclic AMP (cAMP) signaling pathway plays a crucial role in morphogenic transitions and virulence of C. albicans by studying genes encoding adenylate cyclase-associated protein (CAP1) and high-affinity phosphodiesterase (PDE2) (Y. S. Bahn, J. Staab, and P. Sundstrom, Mol. …