Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 21 of 21

Full-Text Articles in Life Sciences

Advances In Understanding Influenza A Virus Infection In Swine: From Diagnostics To Basic Science, Jason Christopher Buehler Jan 2013

Advances In Understanding Influenza A Virus Infection In Swine: From Diagnostics To Basic Science, Jason Christopher Buehler

Graduate Theses and Dissertations

Influenza A virus (IAV) is a member of the family Orthomyxoviridae and is considered a major pathogen for a number of species including humans, swine, and avian species. Historically, the potential of avian and swine influenza A viruses, either through direct infection by intact virus or through incorporation of genetic information into human isolates, have presented major zoonotic risks to human health risks with epidemic and pandemic potential (98). Prior to the 2009 pandemic, experts were concerned that high pathogenic avian IAV, particularly H5N1, was going to become established in the human population and that such establishment would lead to ...


Characterization Of A Thiopurine S-Methyltransferase From Leptospira Borgpetersenii And Assessment Of Pre And Posttesting In The Middle School Classroom, Joy Marie Jackson Jan 2013

Characterization Of A Thiopurine S-Methyltransferase From Leptospira Borgpetersenii And Assessment Of Pre And Posttesting In The Middle School Classroom, Joy Marie Jackson

Graduate Theses and Dissertations

ABSTRACT

Spirochaete is a diverse phylum of Gram-negative bacteria that is located under the order, Spirochaetales, which is divided into three families: Spirochaetacea, Brachyspiraceae, and Leptospiraeae. Research was focused on the latter, specifically, the genus, Leptospira. Leptospira consists of many saprophytic, intermediate pathogenic, and pathogenic species, with L. interrogans (transmitted via contaminated water) and L. borpetersenii (acquired via host to host transmission) causing the majority of leptospirosis cases. To gain insight into the pathogenesis of Leptospira, a putative thiopurine S-methyltransferase (LBJ0800) was exploited. Because this gene is not present in any of the sequenced spirochetes, Brachyspira, Borrelia, Treponema, except Leptospira ...


Direct And Indirect Effects Of Agrochemicals On Bacterial Pathogens And Fecal Indicator Bacteria, Zachery Staley Jan 2013

Direct And Indirect Effects Of Agrochemicals On Bacterial Pathogens And Fecal Indicator Bacteria, Zachery Staley

Graduate Theses and Dissertations

The presence of agrochemical residues in both urban and agricultural water bodies has become ubiquitous, often producing deleterious effects in the impacted watershed including reductions in biodiversity, alterations in species interactions, and toxicity to non-target organisms. While these effects have been studied on metazoan consumers, the consequences of agrochemical contamination on microorganisms, such as bacteria, protozoa, and viruses, are poorly understood. Agrochemicals could act directly on microorganisms, including pathogens, by either facilitating their survival or decreasing their abundance. Further, a multitude of indirect effects of agrochemicals on microorganisms are possible, whereby agrochemicals alter predation, competition, or parasitism on or available ...


Innate Immune Responses To Respiratory Syncytial Virus: Age-Associated Changes, Terianne Maiko Wong Jan 2013

Innate Immune Responses To Respiratory Syncytial Virus: Age-Associated Changes, Terianne Maiko Wong

Graduate Theses and Dissertations

Respiratory syncytial virus (RSV) infection causes ~64 million cases of respiratory disease and 200,000 deaths annually worldwide, yet there is no broadly effective prophylactic or treatment regimen. RSV can produce acute respiratory illness in patients of all ages but strikes the age extremes, infants and the elderly, with highest frequency presumably due to innate immune deficiencies. A higher morbidity and mortality has been reported for the elderly above 65 years of age, which has been attributed to immune senescence. Efforts to generate an effective vaccine have thus far been unsuccessful.

The innate immune system provides the first line of ...


Assessment Of A Modified Double Agar Layer Method To Detect Bacteriophage For Assessing The Potential Of Wastewater Reuse In Rural Bolivia, Sakira N. Hadley Jan 2013

Assessment Of A Modified Double Agar Layer Method To Detect Bacteriophage For Assessing The Potential Of Wastewater Reuse In Rural Bolivia, Sakira N. Hadley

Graduate Theses and Dissertations

Water scarcity is a global concern that impacts many developing countries, forcing people to depend on unclean water sources for domestic, agricultural, and industrial needs. Wastewater is an alternative water source that contains nutrients needed for crop growth. Wastewater reuse for agriculture can cause public health problems because of human exposure to pathogens. Pathogen monitoring is essential to evaluate the compliance of wastewater with established World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA) wastewater reuse guidelines. Indicator organisms are commonly used to detect pathogens in water and wastewater because they are quick and easy to measure, non-pathogenic ...


Considerations For Improved Surveillance Of Influenzavirus A In Swine Populations, Christa Kalberer Goodell Jan 2013

Considerations For Improved Surveillance Of Influenzavirus A In Swine Populations, Christa Kalberer Goodell

Graduate Theses and Dissertations

This thesis consists of 4 chapters. Chapter 1 is a general introduction and road map for contemporary swine surveillance programs, "Protecting our future - A road map for practical, real-time, on-farm infectious disease surveillance". Chapter 2, "Ring test evaluation of the detection of influenza A virus in swine oral fluids by real-time, reverse transcription polymerase chain reaction (rRT-PCR) and virus isolation" has been submitted for publication in the Journal of Veterinary Diagnostic Investigation. Chapter 3, "Probability of the detection of influenza A virus subtypes H1N1 and H3N2 in individual nasal swab and pen-based oral fluid specimens from pigs over time" has ...


Investigating The Control Of Listeria Monocytogenes On Uncured, No-Nitrate-Or-Nitrite-Added Ready-To-Eat Meat Products Using Natural Antimicrobial Ingredients And Post-Lethality Interventions, Nicolas Armando Lavieri Jan 2013

Investigating The Control Of Listeria Monocytogenes On Uncured, No-Nitrate-Or-Nitrite-Added Ready-To-Eat Meat Products Using Natural Antimicrobial Ingredients And Post-Lethality Interventions, Nicolas Armando Lavieri

Graduate Theses and Dissertations

Restrictions on the use of conventional antimicrobials, combined with the restricted use of nitrite and nitrate, have generated concerns over the perceived risk for foodborne illness associated with natural and organic RTE meat and poultry products. Thus, the use of natural antimicrobial interventions alone and in combination with post-lethality interventions as a means to inhibit the recovery and growth of Listeria monocytogenes in naturally cured RTE processed meats was the focus of the work reported in this dissertation. Natural antimicrobials evaluated were cranberry powder, vinegar, and vinegar and lemon juice concentrate. Post-lethality interventions studied were high hydrostatic pressure, lauric arginate ...


Mammalian Orthoreovirus Localization To Stress Granules And Escape From Translation Shutoff, Kate Carroll Jan 2013

Mammalian Orthoreovirus Localization To Stress Granules And Escape From Translation Shutoff, Kate Carroll

Graduate Theses and Dissertations

A clinically benign member of the dsRNA virus family Reoviridae, Mammalian Orthoreovirus (MRV) serves as a model system to determine the nuances of replication within the family. MRV is composed of ten dsRNA gene segments that are contained in a double capsid structure and encode 12-13 viral proteins. It has previously been shown that at early times in MRV infection, granules form throughout the cytoplasm of the host cells that have been termed stress granules (SGs). MRV induces the formation of these SGs by activation of the kinase Protein Kinase R (PKR) which subsequently phosphorylates the initiation factor eIF2α to ...


The Panicum Mosaic Virus-Like 3' Cap-Independent Translation Element: A Translation Enhancer That Functions In Mammalian Systems, Mariko Sada Peterson Jan 2013

The Panicum Mosaic Virus-Like 3' Cap-Independent Translation Element: A Translation Enhancer That Functions In Mammalian Systems, Mariko Sada Peterson

Graduate Theses and Dissertations

In canonical eukaryotic translation initiation, the recognition of mRNA by the translation machinery is facilitated through the binding of the 5' m7G cap structure to eukaryotic initiation factor 4E (eIF4E). This recognition is necessary for efficient translation of the message to occur. In contrast, some viruses lack the 5' cap structure but have alternative mechanisms to initiate translation and express the viral proteins necessary for replication. The positive-strand RNA plant viruses of the panico-, carmo-, umbra-, (1-3) and aureusviruses (4) contain an RNA structure in their 3' UTRs that binds eIF4E (2) and through communication with the 5' UTR, are ...


Sodium Polyphosphate Enhances The Antimicrobial Activities Of Whole And Fractionated Peanut Skin Extract Against Food Spoilage Yeasts In A Model Juice System, Merike Seaman Jan 2013

Sodium Polyphosphate Enhances The Antimicrobial Activities Of Whole And Fractionated Peanut Skin Extract Against Food Spoilage Yeasts In A Model Juice System, Merike Seaman

Graduate Theses and Dissertations

The efficacy of various fractions of Peanut Skin Extract (PSE) in combination with sodium polyphosphate (SPP; BekaPlusTM FS, BK Giulini) were tested in apple juice medium (AJM, a model juice system) against the economically important spoilage yeasts Zygosaccharomyces bailii and Zygosaccharomyces bisporus.

Z. bailii (ATCC 60483) or Z. bisporus (Y108, an industrial isolate) were inoculated in AJM or AJM containing SPP, PSE or combinations of SPP and PSE, then incubated at 30°C for up to 120 h (5 d). Both whole PSE and 9 individual HPLC-separated PSE fractions were tested. A Bioscreen C automated turbidimeter determined the impact ...


Characterization Of Multiple Regulatory Networks And Responses To Environmental Signals In Pseudomonas Syringae During Its Association With Plants, Xilan Yu Jan 2013

Characterization Of Multiple Regulatory Networks And Responses To Environmental Signals In Pseudomonas Syringae During Its Association With Plants, Xilan Yu

Graduate Theses and Dissertations

Pseudomonas syringae is a model bacterial plant pathogen that is adapted for growth and survival on leaf surfaces and in the leaf interior of its host plants. P. syringae likely experiences distinct environmental conditions in different phases of its interaction with plants. In this study, we used global transcriptome profiling of P. syringae pv. syringae B728a to analyze genes and traits that were responsive to growth and survival on the leaf surface versus in the leaf apoplast. We found that the epiphytic environment specifically favors active relocation via flagellar motility, swarming motility, chemosensing, and chemotaxis, whereas the apoplastic environment favors ...


Porcine Reproductive And Respiratory Syndrome Virus: Diagnostic Update And Search For Novel Modified Live Vaccines, Joshua Scott Ellingson Jan 2013

Porcine Reproductive And Respiratory Syndrome Virus: Diagnostic Update And Search For Novel Modified Live Vaccines, Joshua Scott Ellingson

Graduate Theses and Dissertations

Porcine reproductive and respiratory syndrome virus continues to be a significant problem for pork producers. The aim of this body of work was to help stakeholders control and prevention infection with this virus. A literature review of currently available diagnostic tests and guidelines for their interpretation serves as a resource for producers, practitioners, and researchers. The research focus was to evaluate two novel methods to develop improved modified live vaccines. The efficacy of viral chimeras constructed from a commercially available vaccine and a virulent wild-type isolate and the ability to attenuate wild-type isolates with a unique cell passage process are ...


Complete Genome Sequences And Phylogeny Of West Nile Virus Isolates From Southeastern United States, 2003-2012, Crystal Wedin Jan 2013

Complete Genome Sequences And Phylogeny Of West Nile Virus Isolates From Southeastern United States, 2003-2012, Crystal Wedin

Graduate Theses and Dissertations

The study of the evolution and phylogeny of West Nile virus (WNV) has been an important area of research since the introduction of WNV in 1999. However, genome sequencing of isolates from the Southeastern part of the United States has been somewhat limited. To determine how WNV has evolved at a more localized level, ten isolates from Florida and Georgia from 2003-2012 were completely sequenced using Illumina's next-generation technology. In addition, a phylogenetic comparison of both the complete genome and select partial genomes was completed to ensure consistency among the results. This study further demonstrated the dominance of the ...


Regulatory And Mutational Mechanisms For Differential Expression Of The Cmeabc Multidrug Efflux Pump In Campylobacter Jejuni, Tara Leigh Grinnage-Pulley Jan 2013

Regulatory And Mutational Mechanisms For Differential Expression Of The Cmeabc Multidrug Efflux Pump In Campylobacter Jejuni, Tara Leigh Grinnage-Pulley

Graduate Theses and Dissertations

Campylobacter jejuni is a zoonotic, foodborne pathogen causing gastroenteritis in humans. The multidrug efflux pump CmeABC plays a key role in antimicrobial resistance by extruding structurally diverse compounds and is essential for intestinal colonization by mediating bile resistance. Expression of cmeABC is under the control of CmeR, a TetR family transcriptional regulator, and CosR, an oxidative stress response regulator. However, the molecular basis and functional consequences of differential CmeABC expression as well as the interactive role of CosR and CmeR in modulating cmeABC expression are still unknown. To address these questions, we performed two sets of studies. In the first ...


Optimization Of Methods For Culturing Mycobacterium Avium Subsp. Paratuberculosis From Bovine Milk And Colostrum And Application To Samples Collected From Naturally Infected Dairy Cows, Laura Kaitlan Bradner Jan 2013

Optimization Of Methods For Culturing Mycobacterium Avium Subsp. Paratuberculosis From Bovine Milk And Colostrum And Application To Samples Collected From Naturally Infected Dairy Cows, Laura Kaitlan Bradner

Graduate Theses and Dissertations

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne's disease (JD), a chronic granulomatous enteritis of the small intestine of ruminants, taking many years for clinical symptoms to develop. Though primarily transmitted through ingestion of contaminated feces, MAP also can be transmitted through milk and colostrum. Unfortunately, many other microorganisms are present in milk along with MAP. Therefore, a decontamination protocol must be applied to the milk before culture. The objective of this research was to optimize a decontamination and culture protocol for the recovery of MAP from milk. The optimal protocol then was applied to milk ...


Molecular Interactions Between Pea Enation Mosaic Virus And Its Pea Aphid Vector, Lucas Benjamin Linz Jan 2013

Molecular Interactions Between Pea Enation Mosaic Virus And Its Pea Aphid Vector, Lucas Benjamin Linz

Graduate Theses and Dissertations

Insect transmission of plant viruses results in tremendous economic loss within the agricultural sector worldwide. Aphids account for nearly half of insect-borne plant virus transmission. Viruses in the family Luteoviridae are transmitted by aphids in a persistent-circulative manner that requires specific molecular interactions between the aphid and virus. Ingested virions cross the aphid gut and salivary gland epithelial barriers using receptors that have not been identified. We assessed the binding of a model luteovirid, Pea enation mosaic virus (PEMV), to brush border membrane vesicles (BBMV) of the pea aphid, Acyrthosiphon pisum using a two-dimensional far-western blot method. Pea aphid membrane ...


Addressing Fatty Acids Toxicity And Production In Biocatalysts, Ping Liu Jan 2013

Addressing Fatty Acids Toxicity And Production In Biocatalysts, Ping Liu

Graduate Theses and Dissertations

Fatty acids recently gain more attentions due to its potentials as fuel and chemicals. However, they are toxic to biocatalysts like many other biofuel compounds. Understanding the inhibitory mechanism can help to improve the production of fatty acids.

In current study, the toxicity of short chain fatty acids: hexanoic, octanoic, and decanoic acid on Saccharomyces. cerevisiae and Escherichia.coli were inverstigated with a focus on octanoic acid. The toxicity of fatty acids (hexanoic, octanoic, and decanoic acid) in S. cerevisiae is dependent on doses and chain lengths, and also leads to damaged membrane intergirity, which was confirmed by increased membreane ...


Utilities Of Reverse Genetics System As A Platform For The Development Of Porcine Reproductive And Respiratory Syndrome (Prrs) Virus Vaccine, Dong Sun Jan 2013

Utilities Of Reverse Genetics System As A Platform For The Development Of Porcine Reproductive And Respiratory Syndrome (Prrs) Virus Vaccine, Dong Sun

Graduate Theses and Dissertations

Porcine reproductive and respiratory syndrome virus (PRRSV) causes reproductive disorder in breeding pigs and respiratory symptoms in pigs of all ages. The virus continues to bring significant economic losses to swine industry, and is considered to be one of the most important swine pathogens. Vaccination has been utilized to aid or facilitate PRRS control. Among various types of vaccines used, attenuated live virus vaccines appear to be more efficacious than killed virus vaccines. However, the effect of vaccination with attenuated live virus vaccines is crippled by several safety and efficacy issues. First, the vaccine development process is time-consuming. Second, the ...


Development Of A Protein Antigen Based Pneumococcal Vaccine Utilizing A Polyanhydride Nanoparticle Delivery Platform, Amy D. Schoofs Jan 2013

Development Of A Protein Antigen Based Pneumococcal Vaccine Utilizing A Polyanhydride Nanoparticle Delivery Platform, Amy D. Schoofs

Graduate Theses and Dissertations

Streptococcus pneumoniae is the primary cause of bacterial pneumonia and contributes to millions of deaths worldwide annually. The current capsule polysaccharide based vaccines do provide some protection, but the 7 to 23 valent formulations cannot protect against the over 90 serotypes currently known. Pneumococcal surface protein A (PspA) is a promising candidate for a protein-based vaccine against S. pneumoniae, showing protection in immunized mice and providing the advantage of universal protection from all serotypes of the bacterium. This project shows the results of immunizing CBA/N mice intranasally and subcutaneously with PspA encapsulated into a novel polyanhydride nanoparticle delivery platform ...


Prenatal Stress, Depression, And Herpes Viral Titers, Pao-Chu Hsu Jan 2013

Prenatal Stress, Depression, And Herpes Viral Titers, Pao-Chu Hsu

Graduate Theses and Dissertations

Recent studies suggest that some cases of prenatal depression may be associated with reactivation of latent infections of the herpesvirus family. The possible relationships among stress, prenatal depression, and herpes viral reactivation in pregnancy are understudied and the molecular pathways such as the neuroimmune biogenic amine pathway are unidentified. Chronic stress shifts the T helper-1 cell (Th1) cytokine profile to a Th2 profile, which favors virus induced pathogenesis and survival. Pregnancy is also associated with a similar Th2 dominance. In non-pregnant individuals, exposure to psychological or physical stress may be associated with latent herpes viral reactivation and could result in ...


Persistent Infection With Human Herpesvirus-6 In Patients With An Inherited Form Of The Virus: A Newly Described Disease, Shara Pantry Jan 2013

Persistent Infection With Human Herpesvirus-6 In Patients With An Inherited Form Of The Virus: A Newly Described Disease, Shara Pantry

Graduate Theses and Dissertations

Human Herpesvirus 6A (HHV-6A) and 6B (HHV-6B) are ubiquitous betaherpesviruses. Both viruses are associated with a variety of adult disorders including neurological disorder, such as multiple sclerosis and chronic fatigue syndrome. HHV-6 viruses are capable of establishing latency by integration into the telomeres of the host chromosome and are transmitted in a Mendelian manner in approximately one percent of the population. To date little is known about the immunological and neurological consequences of HHV-6 inheritance. This study focused on a unique population of individuals that inherited HHV-6 and present with chronic fatigue-like symptoms, including hypersomnia, generalized fatigue, headache, and short ...