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Articles 1 - 28 of 28
Full-Text Articles in Life Sciences
Harnessing The Anopheles Microbiome To Conditionally Express Anti-Plasmodial Effectors During The Blood Meal, Jackie Shane
Harnessing The Anopheles Microbiome To Conditionally Express Anti-Plasmodial Effectors During The Blood Meal, Jackie Shane
Electronic Theses and Dissertations
The control of vector-borne diseases such as malaria has been an extremely important research subject for hundreds of years. Because of the complex lifecycles of the pathogens that cause these diseases, finding a comprehensive treatment or preventative strategy has proven extremely difficult. Malaria alone is responsible for almost half a million deaths annually, most of them children under 5 years old. This disease is caused by parasitic protists in the genus Plasmodium that are transmitted to humans from Anopheles sp. mosquitoes. Most preventative strategies that are in use today revolve around controlling the vectors, including bed nets, insecticides, and larval …
Host Mediated Mechanisms Of Fungal Cell Spread In A Transparent Zebrafish Infection Model, Allison Scherer
Host Mediated Mechanisms Of Fungal Cell Spread In A Transparent Zebrafish Infection Model, Allison Scherer
Electronic Theses and Dissertations
Innate immunity has developed elegant processes for the detection and clearance of invasive fungal pathogens. Disseminated candidiasis is of significant concern for those with suppressed immune systems or indwelling medical equipment, and mortality in these groups approaches 70%. Poor patient outcomes have spurred the need to understand how this non-motile pathogen spreads in the host. Technical limitations have previously hindered our ability to visualize the role of innate immunity and host tissue barriers in the spread of C. albicans in vivo. Using the zebrafish model to overcome these limitations, we have examined three potential host-mediated mechanisms of dissemination: movement …
Virulence Regulation In Pseudomonas Aeruginosa Via The Alginate Regulators, Algu And Algr, The Posttranscriptional Regulator, Rsma, And The Two-Component System, Algz/R, Sean Stacey
Electronic Theses and Dissertations
Pseudomonas aeruginosa is a Gram-negative bacillus able to colonize a wide variety of environments. In the human host, P. aeruginosa can establish an acute infection or persist and create a chronic infection. P. aeruginosa is able to establish a niche and persist in human hosts by using a wide array of virulence factors used for: movement, killing host cells, and evading immune cells and antibiotics. Understanding virulence factors and their regulation has proved to be an important means of combating the morbidity and mortality of P. aeruginosa as well as the ever-increasing threat of drug resistance. By targeting virulence factors …
The Role Of Non-Neuronal Acetylcholine In Urogenital Chlamydial Infection, Jessica R. Lockhart
The Role Of Non-Neuronal Acetylcholine In Urogenital Chlamydial Infection, Jessica R. Lockhart
Electronic Theses and Dissertations
Chlamydia trachomatiscauses a bacterial sexually transmitted infection, Chlamydia, that is often chronic and casues reproductive complications in women. We hypothesized that Chlamydia infection increases local acetylcholine (ACh) production, which regulates the host’s inflammatory response to the infection. Female mice infected with C. muridarumwere sacrificed at days 3, 9, 15, and 21 post-infection, genital tract tissues harvested, and immunohistochemistry performed to enumerate ACh-producing cells. Infection increased the number of ACh-producing cells in cervical tissue at days 3,15, and 21 post-infection (pi), uterine tissue at day 3 and 9 pi, and ovarian tissue day 3, 15, and 21 pi. These …
The Effects Of Seasonal Variations In Chemistry And Hydrology On The Microbial Community And Its Sulfide Oxidation Potential In A Naturally Acidic Maine Stream, Raymond C. Kahler Iii
The Effects Of Seasonal Variations In Chemistry And Hydrology On The Microbial Community And Its Sulfide Oxidation Potential In A Naturally Acidic Maine Stream, Raymond C. Kahler Iii
Electronic Theses and Dissertations
Sulfide minerals oxidize through interaction with water and oxygen, releasing hydrogen ions. The process often occurs naturally near metal sulfide deposits, and can be accelerated through mining. Microorganisms accelerate the rate of sulfide oxidation. Acidified streams typically contain high metal concentrations (e.g. aluminum) and microbes in these systems may develop resistances to metal toxicity. Stream flow can affect sulfide oxidation and microbial community structure. Baseflow can influence stream chemistry from interactions with the surrounding bedrock, while stormflow affects stream chemistry and the local microbial community through dilution and addition of microbes transported by runoff. Microbial community composition is affected by …
Synthesis And Characterization Of Targeted Bar Encapsulated Polylactic-Co-Glycolic Acid Nanoparticles To Inhibit Porphyromonas Gingivalis Biofilm Formation., Ranjith Radha Krishnan
Synthesis And Characterization Of Targeted Bar Encapsulated Polylactic-Co-Glycolic Acid Nanoparticles To Inhibit Porphyromonas Gingivalis Biofilm Formation., Ranjith Radha Krishnan
Electronic Theses and Dissertations
Periodontal disease is one of the most prevalent infectious diseases worldwide. Between 30-50% of the global adult population suffers from periodontal disease. Some form of periodontitis is present in 46% of American adults, corresponding to annual expenditures in excess of 14 billion dollars for treatment and prevention. Current treatments for periodontal diseases involve mechanical removal of plaque, correction of risk factors, gingival surgery and/or antibiotic therapy. To our knowledge there is no effective therapeutic approach that aims to limit pathogen colonization of the oral biofilm or re-colonization after treatment. Interaction of the pathogen Porphyromonas gingivalis with oral streptococci is critical …
Thermal And Microbial Effects On Brown Macroalgae: Heat Acclimation And The Biodiversity Of The Microbiome, Charlotte Tc Quigley
Thermal And Microbial Effects On Brown Macroalgae: Heat Acclimation And The Biodiversity Of The Microbiome, Charlotte Tc Quigley
Electronic Theses and Dissertations
This dissertation examines effects of stress on brown algal biology from a macroscopic scale by examining the whole aquaculture crops, and at a microscopic level by examining the macroalgal microbiome, across the vertical stress gradient of the intertidal zone and across the latitudes of their biogeographic ranges. Thermal stress negatively affected seedstock gametophytes of the kelp Alaria esculenta isolated from northern and southern locations in Maine. However, previous thermal stress had a positive effect on growth of the next-generation sporophytes. Alaria esculenta has potential as a kelp crop in Maine’s sea vegetable aquaculture sector and implementing this protocol may allow …
Post-Transcriptional Regulation Of Rsma In Pseudomonas Aeruginosa, Ian Miller
Post-Transcriptional Regulation Of Rsma In Pseudomonas Aeruginosa, Ian Miller
Electronic Theses and Dissertations
Pseudomonas aeruginosa is a Gram-negative bacillus found in numerous environments. Gene regulatory mechanisms such as; Two-Component Systems, transcriptional and post-transcriptional regulators, and small non-coding RNAs control the expression of virulence factors that allow P. aeruginosa to initiate acute infections and persist as a chronic infection. A significant post-transcriptional regulator involved in these regulatory networks is the Regulator of Secondary Metabolites (RsmA). In this study, we investigated the contribution of a putative stem-loop on expression of RsmA. We constructed rsmA leader fusions to measure translation with and without the stem-loop present. Secondly, we introduced point mutations to disrupt the formation …
Investigating Present-Day Health Issues Of The American Lobster (Homarus Americanus), Deborah A. Bouchard
Investigating Present-Day Health Issues Of The American Lobster (Homarus Americanus), Deborah A. Bouchard
Electronic Theses and Dissertations
The American lobster, Homarus americanus, H. Milne Edwards, 1837, supports the most economically valuable fishery along the North Atlantic coast of North America. A collapse in lobster populations in Southern New England (SNE) has coincided with increasing ocean temperatures and emerging diseases. This research investigated the etiologies of limp lobster disease (LLD) and epizootic shell disease (ESD), two diseases that continue to cause significant mortality in natural lobster populations. Mortality from LLD is associated with the bacteria Photobacterium indicum and is more intense in impounded lobsters. To more clearly define the community ecology of this suspected opportunistic pathogen, the microbial …
Changes In The Microbial Community Of Lubomirskia Baicalensis Affected By Red Sponge Disease, Colin Rorex
Changes In The Microbial Community Of Lubomirskia Baicalensis Affected By Red Sponge Disease, Colin Rorex
Electronic Theses and Dissertations
Lake Baikal is the oldest known lake and a unique ecosystem, home to several species of fresh water sponge. A disease outbreak affecting the dominant species, Lubormirskia baialensis, was recently reported. The cause of the disease has not been determined but one of the current hypothesis is that the increase in methane concentration is correlated to the disease outbreak. This pilot study characterized the microbiomes of sick and healthy sponges through the use of 16S rRNA sequencing. Sick sponge microbiomes shared a conserved group of taxa while the healthy sponge microbiomes had greater diversity. Indicator species analysis identified two significant …
Characterization Of Type Ii Toxin Anti-Toxin Systems In Aggregatibacter Actinomycetemcomitans., Blair W. Schneider
Characterization Of Type Ii Toxin Anti-Toxin Systems In Aggregatibacter Actinomycetemcomitans., Blair W. Schneider
Electronic Theses and Dissertations
Microbes express many protective mechanisms in response to environmental stress. Toxin/anti-toxin systems encode a biologically active toxin and a labile anti-toxin that inhibits the toxin’s activity. These systems are known to contribute to persister cell and biofilm formation. A. actinomycetemcomitans thrives in the complex oral microbial community and is subjected to continual environmental flux. Little is known regarding the presence and function of TA systems in this organism or their contribution survival in the oral environment. Using BLAST searches and other informatics tools, we identified 11 intact TA systems that are conserved across all seven serotypes of A. actinomycetemcomitans and …
Identification Of “Fhua” Like Genes In Rhizobium Leguminosarum Atcc 14479 And Its Role In Vicibactin Transport And Investigation Of Heme Bound Iron Uptake System, Sushant Khanal
Electronic Theses and Dissertations
Siderophores are low molecular weight, iron chelating compounds produced by many bacteria for uptake of iron in case of iron scarcity. Vicibactin is a trihydroxamate type siderophore produced by Rhizobium leguminosarum bv. trifolii ATCC 14479. This work focuses on identifying an outer membrane receptor involved in the transport of vicibactin. We have confirmed the presence of the putative fhuA gene in R. leguminosarum bv. trifolii ATCC 14479. This bacteria shows mutualistic symbiosis with the red clover plant Trifoliium prantense. Leghemoglobin, with its cofactor heme is present in the plant root nodules that surrounds the infecting organism present in the nodules. …
Reducing Tillage In Small-Scale Permanent Bed Organic Vegetable Production Systems, Jeremiah D. Vallotton
Reducing Tillage In Small-Scale Permanent Bed Organic Vegetable Production Systems, Jeremiah D. Vallotton
Electronic Theses and Dissertations
The response of field-grown vegetable crops to reduced tillage and mulching in permanent beds was evaluated through measuring crop yields, weed pressure, earthworm counts, and soil basal respiration. Two vegetable crops (“Bush Delicata” squash and “Farao” cabbage) were started in April and May of 2016 and 2017 respectively, transplanted in late June, and harvested on 15-Sep-2016 and 25-Aug-2017. Fruit number and weight of squash, and head weight and feeding damage of cabbage were measured. These results suggest that intensive tillage (8” rototill every year) can be successfully reduced to alternating years of shallow (2”) rototilling and a less intensive form …
Characterizing The Virulence Factor Yape In Yersinia Pestis., Tiva Templeton Vancleave
Characterizing The Virulence Factor Yape In Yersinia Pestis., Tiva Templeton Vancleave
Electronic Theses and Dissertations
Yersinia pestis is the causative agent of bubonic plague and is primarily transmitted by fleas. Upon infection, the bacteria rapidly travel to the regional lymph nodes causing inflammation and cellulitis in these tissues (referred to as buboes). Two outer membrane proteins, YapE and Pla, have been implicated to have roles in dissemination to the lymph nodes. Their adhesive properties have shown that they are able to interact with host macrophages thereby increasing their ability to disseminate to regional lymph nodes. More recently, we have shown that YapE is cleaved by another virulence factor important for lymph node colonization, Pla, to …
The Involvement Of Epithelial Cells In Arenavirus-Induced Pathogenesis., Nikole Leslie Margaret Warner
The Involvement Of Epithelial Cells In Arenavirus-Induced Pathogenesis., Nikole Leslie Margaret Warner
Electronic Theses and Dissertations
Mammalian Arenaviruses are a geographically and genetically diverse family of viruses, which is separated into two sub-groups; the Old World (OW) and New World (NW) groups. Of the OW viruses, Lassa virus (LASV), found endemically in Western Africa, is an important human pathogen, causing hundreds of thousands of infections, and several thousand deaths annually. Interestingly, some villages in endemic regions, up to 45% of the population show seropositivity for the virus. It is hypothesized that seropositivity is a result of natural infection through inhalation or ingestion of infectious particles. However, the exact mechanism is still unknown. LASV’s natural reservoir is …
Nutritional Virulence Of Legionella Pneumophila., Ashley M. Best
Nutritional Virulence Of Legionella Pneumophila., Ashley M. Best
Electronic Theses and Dissertations
Legionella pneumophila is an environment organism that parasitizes a wide range of protozoa. Growth within the environmental host primes L. pneumophila for infection of human alveolar macrophages when contaminated aerosols are inhaled. Intracellular replication within either host requires the establishment a replicative niche, known as the Legionella-containing vacuole (LCV). Biogenesis of the LCV depends on the type IVb translocation system, the Dot/Icm, to translocation >320 effectors into the host cytosol. Effectors are responsible for preventing lysosome fusion to the LCV, recruitment of ER-derived vesicles to the LCV, and modulation of a plethora of host processes to promote the intracellular …
Tripartite Interactions Of Legumes With Arbuscular Mycorrhizal Fungi And Rhizobial Bacteria: Insight Into Plant Growth, Seed Yield, And Resource Exchange, Arjun Kafle
Electronic Theses and Dissertations
Under natural conditions, legumes, such as alfalfa (Medicago) and soybean (Glycine max) are colonized with arbuscular mycorrhizal (AM) fungi and rhizobial bacteria forming tripartite interactions. Legumes are important crop species due to their high nutritional and economic values. Most of the previous literatures focused on experiments with an individual symbiont: either AM fungi or rhizobial bacteria, but not with both symbionts at the same time, thus our current understanding of resource exchange in tripartite interactions is limited. It has been reported that AM fungi primarily provide phosphate (P), nitrogen (N), and other nutritional and non-nutritional benefits while rhizobial bacteria solely …
Gtpase-Activating Protein-Binding Protein 1 Plays An Antiviral Role In Porcine Epidemic Diarrhea Virus (Pedv) Replication, Kabita Pandey
Gtpase-Activating Protein-Binding Protein 1 Plays An Antiviral Role In Porcine Epidemic Diarrhea Virus (Pedv) Replication, Kabita Pandey
Electronic Theses and Dissertations
Porcine Epidemic Diarrhea Virus (PEDV) is a non-segmented virus which uses one-stranded, positive-sense RNA as genetic material. PEDV falls under Coronaviridae family and extensive diarrhea and dehydration in nursing piglets are the major clinical signs. This emerging disease leads to huge economic loss in the pig farming. Very less studies are done towards the role of innate immunity in PEDV infection. The formation of Stress granules (SGs) are seen when cells are introduced to different stressful conditions, which also includes viral infections. SGs are formed when one of the four kinases: doublestranded RNA (dsRNA)-dependent protein kinase (PKR), PKR-like endoplasmic reticulum …
Surveillance Of South Dakota Mosquito Abundance, Infection Rate, And Insecticide Susceptibility, Geoffrey P. Vincent
Surveillance Of South Dakota Mosquito Abundance, Infection Rate, And Insecticide Susceptibility, Geoffrey P. Vincent
Electronic Theses and Dissertations
The aim of this dissertation was to survey and evaluate the abundance, infection rate, and insecticide susceptibility of mosquito fauna present in South Dakota. Mosquito surveillance has been conducted across South Dakota to record and track potential West Nile virus (WNV) vectors from 2004 to 2017. The nuisance mosquito Aedes vexans was found to be the most abundant species overall in the state and most abundant in many of the regions. The WNV vector, Culex tarsalis, was found to be the second most abundant mosquito and the most abundant vector mosquito across the state. However, geospatial variation did exist between …
Dissecting Rna Silencing Pathways In Sclerotinia Sclerotiorum, Pauline Mochama
Dissecting Rna Silencing Pathways In Sclerotinia Sclerotiorum, Pauline Mochama
Electronic Theses and Dissertations
RNA silencing, also known as RNA interference, is an essential mechanism in plants, animals and fungi that functions in gene regulation and defense against foreign nucleic acids. In fungi, RNA silencing has been shown to function primarily in defense against invasive nucleic acids. RNA-silencing- deficient fungi show increased susceptibility to virus infection. Plant pathogenic fungi also utilize RNA silencing to silence plant host immunity genes through the delivery of fungal small RNAs into plants. This cross-kingdom RNA silencing facilitates fungal infection of plants. Overall, these findings demonstrate the significant contributions of fungal RNA silencing pathways to fungal virulence and viral …
The Role Of Genomic Versatility In Multi-Niche Preferences Of Escherichia Coli, Gitanjali Nandakafle
The Role Of Genomic Versatility In Multi-Niche Preferences Of Escherichia Coli, Gitanjali Nandakafle
Electronic Theses and Dissertations
Escherichia coli strains are naturally present as either commensals or pathogens in the gastrointestinal tract of mammals and some other vertebrates. Until recently, it was assumed that E. coli are solely associated with the gut and are unable to survive outside of a host for a long period of time, the basis of its use as an indicator organism. Recent reports suggest that E. coli can become naturalized to several tropical, subtropical or temperate soils and aquatic environments, where they have been isolated repeatedly. Several studies have shown that these strains are capable of surviving and proliferating in the environment …
Superresolved Three-Dimensional Analysis Of The Spatial Arrangement Of The Human Immunodeficiency Virus Type-1 (Hiv-1) Envelope Glycoprotein At Sites Of Viral Assembly, Carmen Anne Buttler
Superresolved Three-Dimensional Analysis Of The Spatial Arrangement Of The Human Immunodeficiency Virus Type-1 (Hiv-1) Envelope Glycoprotein At Sites Of Viral Assembly, Carmen Anne Buttler
Electronic Theses and Dissertations
Human Immunodeficiency Virus type 1 (HIV-1) replicates by forcing infected host cells to produce new virus particles, which assemble form protein components on the inner leaflet of the host cell's plasma membrane. This involves incorporation of the essential viral envelope glycoprotein (Env) into a structural lattice of viral Gag proteins. The mechanism of Env recruitment and incorporation is not well understood. To better define this process, we seek to describe the timing of Env-Gag encounters during particle assembly by measuring angular positions of Env proteins about the surfaces of budding particles. Using three-dimensional superresolution microscopy, we show that Env distributions …
Universal Swine Influenza Antigen And Vaccine, Zhao Wang
Universal Swine Influenza Antigen And Vaccine, Zhao Wang
Electronic Theses and Dissertations
Swine influenza A viruses pose a serious concern for global health and worldwide swine industry considering their evasion from vaccine-induced immune responses. Formulation of effective influenza vaccines can be complicated by both antigenic shift to a different subtype of hemagglutinin (HAs) and antigenic drift within a particular HA subtype. To address these concerns, we employed a systematic approach to determine the antigenic determinants of swine influenza A viruses by focusing on H1 and H3 subtypes. In parallel, we used a cross-disciplinary approach including structural biology and modeling, virology, and immunology to identify swine influenza A virus-derived HA fusion intermediates broadly …
Improving The Nutritional Characteristics Of Plant Feedstuff By-Products Using Fungal Metabolism, Jacob Zahler
Improving The Nutritional Characteristics Of Plant Feedstuff By-Products Using Fungal Metabolism, Jacob Zahler
Electronic Theses and Dissertations
Plant feedstuff by-products such as soy processing wastewater, guar korma meal, and sorghum hominy are very different, however, all possess a rich nutrient profile. Lessening their value is the presence of lignocellulose, plant anti-nutritional factors, and unfavorable protein profiles. Fungal conversion processes are an attractive approach to improving the value of these by-products by degrading detrimental fractions of each while simultaneously creating nutrient-rich cell mass. The aim of this research was to improve the value of each by-product for potential application in monogastric diets such as fish. Fungal organisms, both yeast and filamentous fungi, were examined for their ability to …
Replication, Virulence, And Pathogenesis Of Influenza Viruses, Chithra Chembil Sreenivasan
Replication, Virulence, And Pathogenesis Of Influenza Viruses, Chithra Chembil Sreenivasan
Electronic Theses and Dissertations
Influenza D virus (IDV) is a novel influenza virus that infects cattle and swine, with cattle as its primary host species. The goal of our first study was to investigate the replication and transmission of bovine IDV in guinea pigs. Following direct intranasal inoculation of animals, the virus was detected in nasal washes of infected animals during the first 7 days post-infection. High viral titers were obtained from nasal turbinates and lung tissues of directly inoculated animals. Further, bovine IDV was able to transmit from the infected guinea pigs to sentinel animals by means of contact and not by aerosol …
Serological Evidence For The Co-Circulation Of Two Lineages Of Influenza D Virus In Equine Populations Of The Midwest United States, Hunter Theodore Nedland
Serological Evidence For The Co-Circulation Of Two Lineages Of Influenza D Virus In Equine Populations Of The Midwest United States, Hunter Theodore Nedland
Electronic Theses and Dissertations
Influenza D virus (IDV) is a newly described lineage of the Orthomyxoviridae virus family that was first isolated from diseased swine in 2011 and has subsequently been detected in cattle around the world in 2014. In addition, serological evidence for IDV infection in humans has been recently established. Despite all the progress, the full range of susceptible hosts for this novel virus has yet to be determined, but includes swine, bovine, small ruminants and human. This study was designed to determine if equine is a possible host to this newly emerging influenza virus. 364 equine serum samples were collected in …
Role Of Bovine Ileal Sub-Epithelial Myofibroblasts And Epithelial Cells In Innate Immunity, Tirth Uprety
Role Of Bovine Ileal Sub-Epithelial Myofibroblasts And Epithelial Cells In Innate Immunity, Tirth Uprety
Electronic Theses and Dissertations
Gastro-intestinal (GI) tract harbors largest number of microbiota as well as the largest number of immune cells for a given tissue. The host needs to mount an effective immune response against invading pathogens and tolerance against commensals. Thus, regulatory mechanism and barrier function of the GI tract are of utmost importance for appropriate host microbe interaction and gut homeostasis. Intestinal epithelial cells (IECs) act as the first line of defense against invading pathogens. IECs recognize pathogens and commensals and mount an effective innate immune response. Such recognition of pathogens is mediated through germ line encoded pattern recognition receptors (PRRs). Intestinal …
Diversity Of Free – Living Nitrogen – Fixing Bacteria In Soil Of Sioux Prairie Of South Dakota, Nabilah Ali Alshibli
Diversity Of Free – Living Nitrogen – Fixing Bacteria In Soil Of Sioux Prairie Of South Dakota, Nabilah Ali Alshibli
Electronic Theses and Dissertations
There are only two natural ways by which molecular nitrogen can be available to support life, either by free-living or by symbiotic nitrogen fixing bacteria. The best studied diazotrophs form symbiotic associations with plants, primarily legumes and certain tree species, but little is known about how non-leguminous plants such as grasses obtain nitrogen in their environment. Natural prairies have few legumes, thus have less symbiotic nitrogen fixer interaction. This indicates presence of free-living nitrogen (FLN) fixation activity towards the balance of the N cycle. The objective of this study was to characterize the culturable diversity of free-living diazotrophs in native …