Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 10 of 10
Full-Text Articles in Entire DC Network
Calcium-Mediated Induction Of Vibrio Fischeri Es114 Biofilms, Katia Elizabeth Semenchuk
Calcium-Mediated Induction Of Vibrio Fischeri Es114 Biofilms, Katia Elizabeth Semenchuk
Master's Theses
Vibrio fischeri bacteria form biofilms that facilitate symbiotic colonization of the Hawaiian bobtail squid, Euprymna scolopes. These host-associated biofilms require production of the SYP polysaccharide. However, it has been difficult to observe robust biofilm formation in vitro in a laboratory setting using wild-type strain ES114; instead, most work investigating syp-dependent biofilm formation has relied on genetically altered strains. Guided by recent findings that increasing calcium induces c-di-GMP (Tischler et al., 2021), a molecule known in other systems to promote biofilm formation, the question was posed as to whether high levels of calcium alone could promote syp-dependent biofilm formation by ES114. …
How Historic Shipwrecks Influence Dispersal Of Deep-Sea Microbiomes, Rachel Moseley
How Historic Shipwrecks Influence Dispersal Of Deep-Sea Microbiomes, Rachel Moseley
Master's Theses
This thesis investigates how historic shipwrecks potentially shape dispersal of deep-sea microbiomes. Processes impacting dispersal of microbiomes around artificial structures in the ocean and how they connect to other deep-sea habitats is unknown. Dispersal processes are explained for some macroorganisms by theories in ecology, specifically the Theory of Island Biogeography and the Wooden Stepping Stone hypothesis. These have not been investigated for microorganisms, and thus this work will probe if they are applicable to microbial biogeography in this habitat. Experiments were conducted to establish new “island-like” features in near proximity (25-125 m) to wooden-hulled historic shipwrecks in the northern Gulf …
Microplastic Abundance, Distribution And Impacts On Sargassum-Associated Juvenile Fishes In The Gulf Of Mexico, Olivia Lestrade
Microplastic Abundance, Distribution And Impacts On Sargassum-Associated Juvenile Fishes In The Gulf Of Mexico, Olivia Lestrade
Master's Theses
Microplastics are a concern in marine environments because they are highly durable, ubiquitous, and can be mistaken for food and ingested by small organisms. Pelagic Sargassum, an important habitat for larval and juvenile stages of many fish species, is found in large surface aggregations, and may provide complex structure in which microplastics become trapped. This could lead to greater risk of microplastic ingestion by fish early life stages associated with Sargassum habitats. To better understand the impacts of microplastics within Sargassum communities, this study examined 1) microplastic concentrations and ingestion by juvenile fishes associated with Sargassum; 2) the microbial …
Elucidating The Molecular Pathways Involved In The Fitness And Water Stress Response Of Pseudomonas Synxantha 2-79 In The Plant Rhizosphere, Clint Henry D. Pablo
Elucidating The Molecular Pathways Involved In The Fitness And Water Stress Response Of Pseudomonas Synxantha 2-79 In The Plant Rhizosphere, Clint Henry D. Pablo
Master's Theses
Pseudomonas synxantha 2-79 is a biocontrol agent that represents beneficial indigenous rhizobacteria that are broadly distributed in the Pacific Northwest, USA and flourish in the rhizosphere of commercially grown wheat under surprisingly arid conditions. The molecular adaptation of 2-79-like bacteria to plants growing in dry soils is poorly understood. We hypothesized that the ability of 2-79 to colonize and persist in the rhizosphere of water-stressed plants is underpinned by the formation of hydrating biofilms and the utilization of root exudates that contain plant-derived osmoprotectants called quaternary ammonium compounds (QACs). We tested this hypothesis by identifying waters stress response pathways in …
The Effects Of Treating Multispecies Biofilms With Bacteriophage, Alexandria Francis Cooper
The Effects Of Treating Multispecies Biofilms With Bacteriophage, Alexandria Francis Cooper
Master's Theses
Biofilms can be found in any environment within proximity to water and are problematic in an assortment of industries. Numerous efforts have been employed to dislodge biofilms including bacteriophages (viruses that infect bacteria). Phage remediation is a promising solution for combatting biofilms that form on catheters in long term use patients. These biofilms often result in catheter-associated urinary tract infections (CAUTIs) and are the most common type of healthcare related infection reported. Additionally, they result in longer hospital stays and increased morbidity. To date, most of the research on the topic focuses on single species biofilms, despite their rarity in …
The Effect Of Xenon Pulsed-Light Technology On Biofilm Adhered To Stainless Steel Surfaces, Stephanie Jacquez
The Effect Of Xenon Pulsed-Light Technology On Biofilm Adhered To Stainless Steel Surfaces, Stephanie Jacquez
Master's Theses
In food processing, inadequate surface sanitation procedures lead to the formation of biofilms in which bacteria attach and aggregate in a hydrated polymeric matrix of their own synthesis. Formation of these sessile communities and their inherent resistance to existing sanitation procedures and agents are at the root of the risk of bacterial infections for consumers. Due to this existing problem, an effective method for reducing biofilm formation in dairy processing equipment is necessary for dairy products processing. Ultraviolet Pulsed light Technology has shown a positive effect in eliminating microorganism populations on food products. The objective of this work is to …
The Role Of Central Metabolism And Electron Transport In Biofilm Formation By Vibrio Fischeri, Jakob Michael Ondrey
The Role Of Central Metabolism And Electron Transport In Biofilm Formation By Vibrio Fischeri, Jakob Michael Ondrey
Master's Theses
Biofilms protect bacteria from environmental threats, including antibiotics; thus, biofilms formed during infections pose an increasing threat to human health. A natural model used to study biofilm formation in the context of a host is the symbiosis between Vibrio fischeri and its host, the squid Euprymna scolopes. Successful colonization depends on the formation of a biofilm and genes involved in making the polysaccharide matrix component, syp. In culture, biofilm phenotypes, including the formation of wrinkled colonies, similarly depend on syp. However, little is known about other factors that contribute to this phenotype. To expand the utility of currently available genetic …
Identification And Characterization Of Msab Gene Involved In Biofilm Formation And Virulence In Staphylococcus Aureus, Amelsaad Elbarasi
Identification And Characterization Of Msab Gene Involved In Biofilm Formation And Virulence In Staphylococcus Aureus, Amelsaad Elbarasi
Master's Theses
Staphylococcus aureus is an important human pathogen that causes a wide variety of life-threatening infections ranging from minor skin and oral infections to severe infections, such as bacteremia, pneumonia, osteomyelitis, or endocarditis due to the presence and secretion of a large number of virulence factors that are controlled by global virulence regulators in complex networks. Furthermore, S. aureus infections have become a threat to public health because of their high potential to form biofilm, and their ability to resist a wide range of antibiotics has exacerbated further. Therefore, understanding the regulatory networks and developing a drug targeting these networks has …
Role Of Msaa Gene In Regulation Of The Msaabcr Operon And Biofilm Development In Staphylococcus Aureus, Ahmed Alzuway
Role Of Msaa Gene In Regulation Of The Msaabcr Operon And Biofilm Development In Staphylococcus Aureus, Ahmed Alzuway
Master's Theses
Staphylococcus aureus is an important human pathogen that causes wide variety of diseases ranging from chronic biofilm associated infection to acute life threatening infection such as bacteremia, pneumonia, osteomyelitis, or endocarditis, despite the progress with antibiotics used in the treatment of bacterial infections. Furthermore, increased use of prosthetic and indwelling devices in modern medical practices has led to increased infections due to S. aureus. Treating S. aureus infections have become difficult owing to its ability to resist most of the antibiotics; this problem is further exacerbated by ability of MRSA strains to form biofilms. Emergence of community-acquired methicillin resistance …
Characterization Of The Clostridium Difficile Biofilm, Michelle Laning
Characterization Of The Clostridium Difficile Biofilm, Michelle Laning
Master's Theses
Clostridium difficile is a Gram-positive, spore forming bacterium and an opportunistic gastrointestinal pathogen. Clostridium difficile infection (CDI) is a common nosocomial infection. Upon antibiotic treatment, patients can be colonized with C. difficile from ingestion of spores. After colonization, cells produce toxins creating symptoms from diarrhea to pseudomembranous colitis, and many patients develop recurrent infections. Interactions between host epithelium and the bacteria is a critical step in infection, yet the interaction is not well understood. It is not known how C. difficile evades host immune responses. These are important mechanisms to answer in advancing CDI treatment. A biofilm could contribute to …