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The Algz/R Two-Component System Is Responsible For Attenuation Of Virulence In Pseudomonas Aeruginosa, Danielle A. Williams Dec 2017

The Algz/R Two-Component System Is Responsible For Attenuation Of Virulence In Pseudomonas Aeruginosa, Danielle A. Williams

Electronic Theses and Dissertations

Pseudomonas aeruginosa is an important opportunistic pathogen. Many P. aeruginosa virulence factors are regulated by the AlgZ/R two component system. AlgZ is the sensor histidine kinase which phosphorylates AlgR, the response regulator. AlgR activates transcription of different gene targets based upon its phosphorylation state. The genes that encode AlgZ and AlgR are transcribed in an operon. While regulation of algR expression has been well studied, regulation of algZ expression has not. Using a pilW mutant in concert with algZTF-lacZ transcriptional fusion, we conducted a transposon mutagenesis to identify algZ regulators. We identified an unknown autoregulatory loop. The type …


Type Ix Secretion System : Characterization Of An Effector Protein And An Insight Into The Role Of C-Terminal Domain Dimeration In Outer Membrane Translocation., Lahari Koneru Dec 2017

Type Ix Secretion System : Characterization Of An Effector Protein And An Insight Into The Role Of C-Terminal Domain Dimeration In Outer Membrane Translocation., Lahari Koneru

Electronic Theses and Dissertations

Porphyromonas gingivalis and Tannerella forsythia are two of the primary pathogens that are associated in the etiology and progression of chronic periodontitis. In T. forsythia, KLIKK proteases are the recently identified group of proteolytic enzymes that are secreted through Type IX secretion system (T9SS). Among, these KLIKK proteases a synergistic relationship was observed between karilysin and mirolysin in invading the host complement system for the survival of the bacteria. Since, karilysin has been already characterized, in this study we propose to study about mirolysin through structural, biochemical and biological characterization. The obtained results from the experiments has shown the …


Characterization Of Porphyromonas Gingivalis Mfa1 Fimbriae., Jae Yong Lee Aug 2017

Characterization Of Porphyromonas Gingivalis Mfa1 Fimbriae., Jae Yong Lee

Electronic Theses and Dissertations

Porphyromonas gingivalis, an obligate anaerobic bacterium associated with chronic periodontitis, utilizes various virulence factors to achieve pathogenicity, one of which is the Mfa1 fimbriae. As a surface structure comprising Mfa1 major subunit along with accessory fimbrial proteins Mfa2-5, the Mfa1 fimbriae has been shown to mediate the adherence of P. gingivalis to antecedent bacterial colonizers of the oral cavity to cause increased virulence. However, the spatial relationships amongst the individual subunits and their assembly mechanism have remained unclear. Through immuno-electron microscopy, Mfa1-4 were localized on the surface of P. gingivalis with Mfa1 localizing throughout the fimbriae and Mfa2 in …


Expression Profiling Of Non-Coding Rna By Environmental Interactions In Innate Immunity, Jacob R. Longfellow Aug 2017

Expression Profiling Of Non-Coding Rna By Environmental Interactions In Innate Immunity, Jacob R. Longfellow

Electronic Theses and Dissertations

Cystic fibrosis (CF) is a genetic disorder that affects 30,000 people in the United States and currently has no cure. Although CF affects all of the body’s systems, it is largely characterized as a lung disease. CF is caused by a mutation in both copies of the gene for cystic fibrosis transmembrane conductance regulator (CFTR). A mutation in the CFTR gene leads to improper movement of chloride ions and water into the airways, which dysregulates the airway surface liquid volume and composition. Individuals with CF are prone to lung infections due to inefficient bacterial clearance and by the age of …


Porphyromonas Gingivalis Infection In Gestational Diabetes Mellitus And Survival In Tobacco Smokers., Himabindu Gogeneni Aug 2017

Porphyromonas Gingivalis Infection In Gestational Diabetes Mellitus And Survival In Tobacco Smokers., Himabindu Gogeneni

Electronic Theses and Dissertations

This thesis contains a clinical project and distinct basic science project. Gestational diabetes mellitus occurs in 4% of pregnancies and increases the risk of birth defects, pre-term birth, and miscarriage. Gingivitis during pregnancy also increases the risk for poor pregnancy outcome. Gingivitis is a bacterial-induced disease, and specific plaque pathogens have been associated with systemic sequelae to periodontal inflammation. Therefore, we set out to monitor oral infection with three key periodontopathogens (Porphyromonas gingivalis, Filifactor alocis, and Treponema denticola) and the systemic inflammatory burden [C-reactive protein (CRP) in pregnant women with and without gingivitis and gestational diabetes. Gingivitis …


Candida And Pseudomonas Interact To Enhance Mucosal Infection In Transparent Zebrafish, Audrey C. Bergeron Jul 2017

Candida And Pseudomonas Interact To Enhance Mucosal Infection In Transparent Zebrafish, Audrey C. Bergeron

Electronic Theses and Dissertations

Polymicrobial communities exist throughout the human body and include both fungi and bacteria. During disease, cross-kingdom interactions among bacteria, fungi, and/or the immune system can alter virulence and lead to complex polymicrobial infections. The fungus C. albicans is among the most commonly isolated fungi in the context of fungal-bacterial co-infections and is often accompanied by the bacterium P. aeruginosa at a variety of sites throughout the body including mucosal tissues such as the lung. In vitro, C. albicans and P. aeruginosa have a cyclic, bi-directional, and largely antagonistic relationship, but these interactions do not account for the role of the …


Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett May 2017

Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett

Electronic Theses and Dissertations

Lilium grayi (Gray’s Lily), a southern Appalachian endemic species, is threatened by a Lilium-specific fungal pathogen, Pseudocercosporella inconspicua. The disease is characterized by tan lesions that can cause early senescence, while also lowering seed production and viability. This project tested for P. inconspicua conidia and accessed health at nine locations. The disease was present and ubiquitous across the range of L. grayi. Through identification of P. inconspicua conidia in the field, L. superbum (Turk’s Cap Lily) was identified as an additional host, while L. michauxii (Michaux’s Lily) was disease-free. However, infection was inducible in both species. With …


Function Of The Enterobactin Operon Of A. Actinomycetemcomitans In The Presence Of Catecholmines And Iron., Taylor Johnson May 2017

Function Of The Enterobactin Operon Of A. Actinomycetemcomitans In The Presence Of Catecholmines And Iron., Taylor Johnson

Electronic Theses and Dissertations

Background: Aggregatibacter actinomycetemcomitans (Aa) possesses a two-component system, QseBC, which is key in biofilm formation/virulence and is activated in the presence of iron-catecholamine complexes. Aa does not synthesize enterobactin, a catechol-based siderophore, yet possesses the machinery for recognition and uptake. We hypothesize that Aa is able to acquire iron by catecholamine mediation through the enterobactin receptor/transporter. Methods: By insertional mutation, we attempted to delete the enterobactin permease from the genome using suicide vector pJT1. A growth curve of truncated mutant ΔfepA was also conducted to observe growth in the presence of iron and catecholamines. Statistical significance was determined by ANOVA …


The Neonatal Anti-Viral Response Fails To Control Measles Virus Spread In Neurons Despite Interferon-Gamma Expression And A Th1-Like Cytokine Profile, Priya Ganesan Jan 2017

The Neonatal Anti-Viral Response Fails To Control Measles Virus Spread In Neurons Despite Interferon-Gamma Expression And A Th1-Like Cytokine Profile, Priya Ganesan

Electronic Theses and Dissertations

Neonates are highly susceptible to infections in the central nervous system (CNS) and have a greater risk of viral infections and encephalopathies. Neurotropic viral infections can lead to blindness, hearing loss and neurological deficiencies such as cognitive impairment, epilepsy, and even death in the neonatal and pediatric populations. Viral infections also are hypothesized to indirectly contribute to neurodegenerative and neuropsychiatric diseases such as Schizophrenia and Parkinson’s disease later in life due to early neuronal damage or stress. Many diverse viruses are capable of invading the neonatal CNS including Borna Disease Virus, Coxsackievirus (CV), Herpes simplex viruses (HSV), and measles virus. …


Genetic Interference And Receptor Biology Of Neglected Influenza Viruses, Runxia Liu Jan 2017

Genetic Interference And Receptor Biology Of Neglected Influenza Viruses, Runxia Liu

Electronic Theses and Dissertations

Influenza B virus (IBV) is an important pathogen that infects humans and causes seasonal influenza epidemics. By using next-generation sequencing (NGS) approach, we analyzed total mRNAs extracted from A549 cells infected with B/Brisbane/60/2008, and identified four defective genomes in IBV with two from the polymerase basic subunit 1 (PB1) segment and the other two from the matrix (M) segment. Each of them can potently inhibit the replication of IBV. One derived from PB1 segment was able to interfere modestly with influenza A virus (IAV) replication. The productions of the four defective RNAs are not dependent on the cell types. The …


Senecavirus A: Epidemiology, Pathogenesis And Infection Dynamics, Lok Raj Joshi Jan 2017

Senecavirus A: Epidemiology, Pathogenesis And Infection Dynamics, Lok Raj Joshi

Electronic Theses and Dissertations

Senecavirus A (SVA) is a positive sense single-stranded virus that belongs to the genus Senecavirus within the family Picornaviridae. Senecavirus has been present in US swine population since 1988. However, there have been only a few reports of SVA associated with disease in last two decades. In late 2014 early 2015, a sudden increase in the number of cases of Senecavirus A associated with vesicular disease was observed in Brazil, the US and China. Affected pigs presented vesicles on snout, coronary band, and dewclaw. Additionaly, increased neonatal mortality has been reported in the field. Many aspects of SVA epidemiology, …


The Synthetic Biology Of N2-Fixing Cyanobacteria For Photosynthetic Terpenoid Production, Charles T. Halfmann Jan 2017

The Synthetic Biology Of N2-Fixing Cyanobacteria For Photosynthetic Terpenoid Production, Charles T. Halfmann

Electronic Theses and Dissertations

In the last few decades, concerns over global climate change, energy security, and environmental pollution have been rising. To overcome these challenges, the concept of “-nth generation” biofuels has emerged as a strategy to convert solar radiation into fuels and bulk industrial chemicals for societal use, while decreasing our consumption of nonrenewable energy sources. Nitrogen-fixing cyanobacteria hold a distinct advantage in biofuel production over plants, given their ability to convert sunlight, air (CO2 and N2), and mineralized water to energy-dense carbon molecules, as well as fix atmospheric nitrogen gas into ammonia for metabolism. Engineered cyanobacteria with …


Effects Of Fertilizer And Shade Management On Nitrogen Mineralization, Nitrifying Microbial Abundance And Nitrogen-Fixing Capacity Of Erythrina Poeppigiana In Coffee (Coffea Arabica) Agroforestry Systems In Costa Rica, Stuart E. Barker Iii Jan 2017

Effects Of Fertilizer And Shade Management On Nitrogen Mineralization, Nitrifying Microbial Abundance And Nitrogen-Fixing Capacity Of Erythrina Poeppigiana In Coffee (Coffea Arabica) Agroforestry Systems In Costa Rica, Stuart E. Barker Iii

Electronic Theses and Dissertations

Worldwide chemical fertilizer use has increased by four times during the last 50 years. Conventional agricultural systems have a high nitrifying nature, resulting in a loss of nearly 70% of overall nitrogen (N) fertilizer inputs, an estimated economic loss of $81 billion. Over application of fertilizer is rampant in tropical developing nations in Central America, where coffee is major crop. Agroforestry offers ecologically sustainable land management strategies that promote the provision of ecosystem services such as, protection of biodiversity, climate change mitigation, and water and soil regulation. When legume trees are incorporated as the shade tree in coffee production, direct …


Effects Of Root Isoflavonoids And Hairy Root Transformation On The Soybean Rhizosphere Bacterial Community Structure, Laura White Jan 2017

Effects Of Root Isoflavonoids And Hairy Root Transformation On The Soybean Rhizosphere Bacterial Community Structure, Laura White

Electronic Theses and Dissertations

Rhizodeposits play a key role in shaping rhizosphere microbial communities. In soybean, isoflavonoids are a key rhizodeposit component that aid in plant defense and enable symbiotic associations with rhizobia. However, it is uncertain if and how they influence rhizosphere microbial communities. Isoflavonoid biosynthesis was silenced via RNA interference of isoflavone synthase in soybean hairy root composite plants. Successive sonication was implemented to isolate soil fractions from 3 different rhizosphere zones at 1 and 3 weeks post planting. PCR amplicons from 16S rRNA gene variable regions V1- V3 and V3-V5 from these soil fractions were analyzed via denaturing gradient gel electrophoresis …


Studying Microflora Of Semi-Hard Cheese, And Sporulation Within Contact Surface Biofilms, Dalia Khan Jan 2017

Studying Microflora Of Semi-Hard Cheese, And Sporulation Within Contact Surface Biofilms, Dalia Khan

Electronic Theses and Dissertations

The first study was conducted on commercial Italian semi-hard cheese samples that were analyzed microbiologically to understand the effect of fast and slow rate of cooling on cheese microflora during ripening process at different temperatures. A cheese plant noticed an active growth of non-starter lactic acid bacteria, especially the heterofermentative bacteria, in ripened cheese blocks, which weren’t fully cooled. For that, three cheese sample sets, each having 8 samples, were received from the cheese plant for microbiological analysis. The first set included a group of fast cooled cheese samples to 38°F, and the other group was slow cooled to 50°F. …


Phylogenetic And Associated Phenotypic Analysis Of Salmonella Enterica Serovar Mbandaka, Linto Antony Jan 2017

Phylogenetic And Associated Phenotypic Analysis Of Salmonella Enterica Serovar Mbandaka, Linto Antony

Electronic Theses and Dissertations

Food borne salmonellosis is a global public health concern caused by Salmonella, that causes enteric disease both in humans and animals. Most of the pathogenic Salmonella serovars fall under Salmonella enterica subspecies enterica, a major subspecies group that includes more than 50% of total identified Salmonella serovars. New serovars are identified each year and overall incidence of salmonellosis may mask the outbreak incidences caused by individual serovars. Infrequently reported serovar outbreaks can be a significant threat to public health. Salmonella enterica serovar Mbandaka is one of the infrequently reported causative agents of non-typhoidal salmonellosis in USA. But it …


Enhancing Cellulase Production Of Aureobasidium Pullulans For Use In Converting Dried Distillers’ Grains With Solubles Into A Higher Protein Feed, Emily L. Baldwin Jan 2017

Enhancing Cellulase Production Of Aureobasidium Pullulans For Use In Converting Dried Distillers’ Grains With Solubles Into A Higher Protein Feed, Emily L. Baldwin

Electronic Theses and Dissertations

Main limitations of dried distillers’ grains with solubles (DDGS) as meal for monogastric animals is the presence of high fiber content, reduced fat content, and poor amino acid balance. This causes a reduced economic value of DDGS for these species due to its low inclusion rates. The goal of this theses was to create new strains of a fungus, Aureobasidium pullulans, with enhanced cellulase production and use it to optimize an enzymatic saccharification, pretreatment, and fungal conversion process to enhance the nutritional value of DDGS. Various combinations of enzymatic saccharification, physical/chemical pretreatments, and mutant strains of fungi were investigated …


Intranasal Immunization Of Pigs With Porcine Reproductive And Respiratory Syndrome Virus Like Particles Plus 2’, 3’ –Cgamp Vaccigrade™ Adjuvant Exacerbates Viremia After Virus Challenge, Alexandria Marie Van Noort Jan 2017

Intranasal Immunization Of Pigs With Porcine Reproductive And Respiratory Syndrome Virus Like Particles Plus 2’, 3’ –Cgamp Vaccigrade™ Adjuvant Exacerbates Viremia After Virus Challenge, Alexandria Marie Van Noort

Electronic Theses and Dissertations

Porcine reproductive and respiratory syndrome virus (PRRSV) is an economically devastating virus that causes a persistent infection and spreads quickly. The virus causes abortions in sows and respiratory diseases in young piglets. Current PRRSV vaccines appear to provide limited cross-protection. A virus-like particles (VLPs) vaccine is made up of key PRRSV structural proteins, which could be cross protective among the different strains. We tested PRRSV VLPs as a vaccine candidate with a 2’, 3’-cGAMP VacciGradeTM adjuvant against pigs infected with PRRSV after intranasal immunization to evaluate the immune response and protective efficacy by the VLPs and adjuvant. The VLPs contain …


Surveillance Of Emerging Livestock Viruses, Faten A. Okda Jan 2017

Surveillance Of Emerging Livestock Viruses, Faten A. Okda

Electronic Theses and Dissertations

Accurate and rapid diagnostic tests are essential for the management and control of emerging infectious diseases. Therefore, the overall goals of studies presented in this dissertation were to provide improved diagnostic and surveillance capabilities for several emerging viral diseases impacting the livestock industry and to provide insight into appropriate control strategies. Recent, severe outbreaks of porcine epidemic diarrhea virus (PEDV) in Asia and North America highlighted the need for well-validated diagnostic tests for identification of PEDV infected animals and evaluation of their immune status. PEDV was first detected in the U.S. in May 2013 and another swine coronavirus, porcine deltacoronavirus …