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Breastfeeding Among Working Mothers In Saudi Arabia, Maryam Suliman Alhabas Jan 2016

Breastfeeding Among Working Mothers In Saudi Arabia, Maryam Suliman Alhabas

Theses and Dissertations

Objective: To examine the relationship of not having breastfeeding support policy in workplace such as employees pumping breast milk or breastfeeding their infant while at work policy to early initiation of formula and cessation of breastfeeding. Design: Crosssectional study. Setting and Subjects: A total of 273 workingwomen, working in 12 different organizations in Riyadh, KSA. Method: An electronic questionnaire survey was administered to 340 workingwomen in 12 different organizations in Riyadh. Questions were about participants’ demographics and employment characteristics, breastfeeding support services in their workplace, knowledge about breastfeeding benefits, breastfeeding duration after return to work, and formula initiation. Results: Having …


Themes In Therapy With Emerging Adults: A Qualitative Study, Brian Louie Jan 2016

Themes In Therapy With Emerging Adults: A Qualitative Study, Brian Louie

Theses and Dissertations

The path to adulthood has traditionally been marked by demographic transitions, such as graduating from college, attaining employment, becoming married, and having a child. Previous models of development have conceptualized adolescence as a time of identity exploration and consolidation. However, in the US, as well as many other countries, the timeline for attaining the aforementioned markers has been delayed. Additionally, a significant portion of individuals between the ages of 18 to 29, across several counties, report not seeing themselves fully as adults, and ascribing internal changes, such as taking responsibility for one’s actions, as more indicative of adulthood status. Emerging …


Themes In Therapy With Emerging Adults : A Qualitative Study, Brian Louie Jan 2016

Themes In Therapy With Emerging Adults : A Qualitative Study, Brian Louie

Theses and Dissertations

The path to adulthood has traditionally been marked by demographic transitions, such as graduating from college, attaining employment, becoming married, and having a child. Previous models of development have conceptualized adolescence as a time of identity exploration and consolidation. However, in the US, as well as many other countries, the timeline for attaining the aforementioned markers has been delayed. Additionally, a significant portion of individuals between the ages of 18 to 29, across several counties, report not seeing themselves fully as adults, and ascribing internal changes, such as taking responsibility for one’s actions, as more indicative of adulthood status. Emerging …


System Genetic Analysis Of Mechanisms Underlying Excessive Alcohol Consumption, Maren L. Smith Jan 2016

System Genetic Analysis Of Mechanisms Underlying Excessive Alcohol Consumption, Maren L. Smith

Theses and Dissertations

Increased alcohol consumption over time is one of the characteristic symptoms of Alcohol Use Disorder (AUD). The molecular mechanisms underlying this escalation in intake is still the subject of study. However, the mesocortical and mesolimbic dopamine pathways, and the extended amygdala, because of their involvement in reward and reinforcement are believed to play key roles in these behavioral changes. Multiple gene expression studies have shown that alcohol affects the expression of thousands of genes in the brain. The studies discussed in this document use the systems biology technique of co-expression network analysis to attempt to find

patterns within genome-wide expression …


A Pipeline For Creation Of Genome-Scale Metabolic Reconstructions, Shaun W. Norris Jan 2016

A Pipeline For Creation Of Genome-Scale Metabolic Reconstructions, Shaun W. Norris

Theses and Dissertations

The decreasing costs of next generation sequencing technologies and the increasing speeds at which they work have lead to an abundance of 'omic datasets. The need for tools and methods to analyze, annotate, and model these datasets to better understand biological systems is growing. Here we present a novel software pipeline to reconstruct the metabolic model of an organism in silico starting from its genome sequence and a novel compilation of biological databases to better serve the generation of metabolic models. We validate these methods using five Gardnerella vaginalis strains and compare the gene annotation results to NCBI and the …


Identifying Parameters For Robust Network Growth Using Attachment Kernels: A Case Study On Directed And Undirected Networks, Ahmed F. Abdelzaher Jan 2016

Identifying Parameters For Robust Network Growth Using Attachment Kernels: A Case Study On Directed And Undirected Networks, Ahmed F. Abdelzaher

Theses and Dissertations

Network growing mechanisms are used to construct random networks that have structural behaviors similar to existing networks such as genetic networks, in efforts of understanding the evolution of complex topologies. Popular mechanisms, such as preferential attachment, are capable of preserving network features such as the degree distribution. However, little is known about such randomly grown structures regarding robustness to disturbances (e.g., edge deletions). Moreover, preferential attachment does not target optimizing the network's functionality, such as information flow. Here, we consider a network to be optimal if it's natural functionality is relatively high in addition to possessing some degree of robustness …


Characterization Of 1-Deoxy-D-Xylulose 5-Phosphate Reductoisomerase (Dxr) From Vibrio Vulnificus, Nikita K. Ussin Jan 2016

Characterization Of 1-Deoxy-D-Xylulose 5-Phosphate Reductoisomerase (Dxr) From Vibrio Vulnificus, Nikita K. Ussin

Theses and Dissertations

Vibrio vulnificus, a gram-negative bacterium, is the leading cause of seafood-borne illnesses and mortality in the United States. Previous studies of bacterial pathogens have identified a metabolite essential to V. vulnificus growth and function. 1-deoxy-D-xylulose 5-phosphate reductoisomerase (Dxr) is an essential enzyme in the viability of many bacteria and catalyzes the rearrangement of 1-deoxy-D-xylulose 5-phosphate (Dxp) to 2-C-methylerythritol 4-phosphate (MEP) within the MEP pathway found in plants and bacteria. Previous studies have been conducted to characterize Dxr homologs from other pathogens including E. coli, M. tuberculosis, and P. falciparum. Information on the structural and enzymatic characteristics of Dxr from Vibrio …


Vulnerability In The Classroom: How Undergraduate Business Instructors' Ability To Build Trust Impacts The Student's Learning Experience, Shannon Huddy Jan 2016

Vulnerability In The Classroom: How Undergraduate Business Instructors' Ability To Build Trust Impacts The Student's Learning Experience, Shannon Huddy

Theses and Dissertations

Vulnerability is the ability to risk emotional exposure, chance making a mistake, or disclose personal information because the outcome is viewed as favorable. Vulnerability is a highly effective way to build trust with others. Trust is a valued leadership trait within corporate business because it encourages employees to take risks, share information, and ultimately become more effective and productive (Robbins & Judge, 2013). This paper explores the practicing of vulnerability in college-level business classrooms to appropriately prepare business students to become leaders who are able to build trust within the workplace. To further understand vulnerability in the classroom and develop …


Strengths-Based Treatment Of Substance Use Disorders: A Critical Analysis Of The Literature, Jennifer A. Berg Jan 2016

Strengths-Based Treatment Of Substance Use Disorders: A Critical Analysis Of The Literature, Jennifer A. Berg

Theses and Dissertations

This critical analysis of the literature is a comprehensive collection and review of the literature on the strengths-based perspective as it is applied to the treatment of substance use disorders. Literature was collected, analyzed, and critically evaluated to consolidate the existing research on strengths-based treatment approaches, identify ways in which the strengths-based perspective is congruent with culturally competent practice, and to identify strengths, weaknesses, and gaps in the literature. Analyses reveal that there are numerous components of the strengths-based perspective that are congruent with culturally competent practice and that strengths-based treatment approaches may serve as an effective adjunct or alternative …


Modern Estimation Problems In Group Testing, Md Shamim Sarker Jan 2016

Modern Estimation Problems In Group Testing, Md Shamim Sarker

Theses and Dissertations

In the simplest form of group testing, pools are formed by compositing a fixed number of individual specimens (e.g., blood, urine, swab, etc.) and then the pools are tested for a binary characteristic, such as presence or absence of a disease. Group testing is commonly used to screen for a variety of sexually transmitted diseases in epidemiological applications where the main goal is to increase testing efficiency. In this dissertation, we study three estimation problems that are motivated by real-life applications. We propose new methods to model group testing data for both single and multiple infections. In the first problem, …


A Weighted Gene Co-Expression Network Analysis For Streptococcus Sanguinis Microarray Experiments, Erik C. Dvergsten Jan 2016

A Weighted Gene Co-Expression Network Analysis For Streptococcus Sanguinis Microarray Experiments, Erik C. Dvergsten

Theses and Dissertations

Streptococcus sanguinis is a gram-positive, non-motile bacterium native to human mouths. It is the primary cause of endocarditis and is also responsible for tooth decay. Two-component systems (TCSs) are commonly found in bacteria. In response to environmental signals, TCSs may regulate the expression of virulence factor genes.

Gene co-expression networks are exploratory tools used to analyze system-level gene functionality. A gene co-expression network consists of gene expression profiles represented as nodes and gene connections, which occur if two genes are significantly co-expressed. An adjacency function transforms the similarity matrix containing co-expression similarities into the adjacency matrix containing connection strengths. Gene …


Considerations In The Provision Of Mental Health Services Toward Arabs, Dalia Khoury Jan 2016

Considerations In The Provision Of Mental Health Services Toward Arabs, Dalia Khoury

Theses and Dissertations

Existing evidence suggests that disparities exist in the use of mental health services by Arabs in the U.S. While there are likely many factors that contribute, lack of cultural competence of mental health providers is one potentially important barrier for mental health service use among racial/ethnic minorities, including Arabs. The primary purpose of this study was to identify and examine factors related to the development and existence of cultural competence toward Arabs. Variables measuring demographics, professional characteristics, familiarity with Arabs, prior experience and knowledge of Arabs, and readiness for change were tested with a randomly selected sample of mental health …


Resolution Of Inflammation Rescues Axon Initial Segment Disruption, Nicholas M. George Jan 2016

Resolution Of Inflammation Rescues Axon Initial Segment Disruption, Nicholas M. George

Theses and Dissertations

Axonal domains are required for proper neuron function. These domains are unstable and degenerate concurrent with the inflammation in multiple sclerosis (MS) and the inflammatory disease models experimental autoimmune encephalomyelitis (EAE) and lipopolysaccharide (LPS) induced inflammation. Previous studies from our laboratory have shown that the axon initial segment (AIS) is maintained independently of the presence of myelin, but that AIS disruption is seen in MS as well as EAE and LPS-mediated inflammation. AIS loss can be interrupted in the early stage of EAE using the anti-inflammatory drug Didox. However, the potential for Didox directed repair of the AIS in later …


Influence Of Historic Landscapes And Contemporary Species Management On Chesapeake Bay Bald Eagles And Osprey, Catherine B. Viverette Jan 2016

Influence Of Historic Landscapes And Contemporary Species Management On Chesapeake Bay Bald Eagles And Osprey, Catherine B. Viverette

Theses and Dissertations

Influence of historic landscapes and contemporary species management on Chesapeake Bay Bald Eagles and Osprey

Catherine B. Viverette

Co-distributed species with well documented demographic histories can provide good models for testing alternative hypotheses about the impact of evolutionary history, contemporary landscapes, and species management on current distribution and population structure. The Osprey (Pandion haliaetus) and Bald Eagle (Haliaeetus leucocephalus) have been extensively studied, managed and monitored across their North American breeding range, particularly in the Chesapeake Bay. We used a combination of ecological niche modelling, diet reconstruction, and population genetic modeling to understand the role of …


Curcumin/Melatonin Hybrids As Neuroprotective Agents For Alzheimer's Disease, John Saathoff Jan 2016

Curcumin/Melatonin Hybrids As Neuroprotective Agents For Alzheimer's Disease, John Saathoff

Theses and Dissertations

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the leading cause of dementia, affecting ~5.2 million Americans. Current FDA approved medications provide mainly symptomatic relief and there are no agents available to delay or cure this disease. Multiple factors such as amyloid-β aggregates, dyshomeostasis of biometals, oxidative stress, and neuroinflammation have been implicated in the development of AD. Even though significant advances have been made in understanding the mechanisms leading to AD, the exact etiology still remains elusive. Given AD’s multifactorial nature, a multifunctional strategy of small molecule design would help to identify novel chemical templates. Recently our lab …


Role Of Vav2 In Podocyte Inflammasome Activation And Glomerular Injury During Hyperhomocysteinemia, Sabena Conley Jan 2016

Role Of Vav2 In Podocyte Inflammasome Activation And Glomerular Injury During Hyperhomocysteinemia, Sabena Conley

Theses and Dissertations

Hyperhomocysteinemia (hHcys) is a widely known pathogenic factor in the progression of end-stage renal disease (ESRD) and it is also associated with an increased risk for injurious cardiovascular pathologies during ESRD. HHcys is linked to the formation and activation of the NOD-like receptor protein 3 (NLRP3) inflammasome, characterized as a critical early mechanism initiating the inflammatory response. NADPH oxidase (NOX)-derived reactive oxygen species (ROS) mediate the activation of the NLRP3 inflammasome in podocytes in response to elevated levels of homocysteine (Hcys) in vitro and in vivo. However, it remains unknown how NLRP3 inflammasome activation is triggered by NOX. The …


Concealing Stigmatized Sexual Orientation, Accepting Versus Non-Accepting Attitudes, And Ego Depletion, Nicole Gigi Giordano Jan 2016

Concealing Stigmatized Sexual Orientation, Accepting Versus Non-Accepting Attitudes, And Ego Depletion, Nicole Gigi Giordano

Theses and Dissertations

The current study was designed with the aim of increasing the understanding of

how concealing or disclosing a stigmatized sexual identity to a perceived accepting/non- accepting person affects ego depletion. Ego Depletion, (Baumeister, 1998) refers to the idea that certain tasks exhaust a limited pool of cognitive resources. Previous literature has explored how concealing a stigmatized identity is ego depleting; however, an examination of the relationship between ego depletion and the concealment of the specific identity as a sexual minority has not yet been explored. LGBQ individuals are often faced with the challenge of navigating social situations to determine if …


Characterization Of Two Surface Proteins From The Lyme Spirochete And Their Roles During Mammalian Infection, Robert Anthony Gaultney Jan 2016

Characterization Of Two Surface Proteins From The Lyme Spirochete And Their Roles During Mammalian Infection, Robert Anthony Gaultney

Theses and Dissertations

Borrelia burgdorferi is an enigmatic bacterial pathogen that afflicts a large proportion of the world population as the causative agent of Lyme disease. The bacterium has a number of factors that promote virulence including a complex and dynamic array of extracellular proteins that can interact with various molecules of an infected host. One such molecule, fibronectin, is a key glycoprotein in the ECM of mammalian hosts with multiple characterized functions. B. burgdorferi encodes multiple known Fn-binding proteins, and has an additional putative protein BB0347 that may also bind Fn. Another protein, MlpJ, is homologous to a known hemin-binding protein, which …


Genetic And Epigenetic Variations In Asthma And Wheeze Illnesses, Todd M. Everson Dec 2015

Genetic And Epigenetic Variations In Asthma And Wheeze Illnesses, Todd M. Everson

Theses and Dissertations

Asthma, a chronic respiratory condition, is common worldwide with no cure and limited effective prevention strategies. It is well recognized that asthma has a multifaceted etiology, though many of the underlying mechanisms involved in asthma development, persistence and remission are still convoluted. Epigenetic mechanisms, such as DNA methylation, regulate gene-expression but are not related to changes in the actual DNA sequence. Recently, differential patterns of DNA methylation within many genes have been associated with asthma, particularly within genes involved in the differentiation of pro-inflammatory T-helper 2 (Th2) cells. DNA methylation patterns within less known biologic pathways undoubtedly are involved in …


Detection Of Flavobacterium Columnare In Tissues And Pond Water Using Real-Time Polymerase Chain Reaction, Gordon Derek Gibbs Dec 2015

Detection Of Flavobacterium Columnare In Tissues And Pond Water Using Real-Time Polymerase Chain Reaction, Gordon Derek Gibbs

Theses and Dissertations

Flavobacterium columnare, a Gram-negative rod-shaped bacterium, is the causative agent of columnaris disease in a variety of fish hosts but is of particular significance to the catfish industry located in the southeastern United States. Columnaris infections are a leading cause of mortalities in catfish ponds, occurring alone or in conjunction with other diseases. Typical diagnostic methods for columnaris infections involve the use of selective media following the observation of gross signs of disease. A real-time quantitative PCR (qPCR) assay to estimate the quantity of bacteria present in environmental and tissue samples was developed and validated. The genetic variability seen in …


Characterization Of The Ability Of Yeast Probiotics And Paraprobiotics To Directly Interact With Gram-Positive And Gram-Negative Bacteria, Gabriel Alviola Posadas Dec 2015

Characterization Of The Ability Of Yeast Probiotics And Paraprobiotics To Directly Interact With Gram-Positive And Gram-Negative Bacteria, Gabriel Alviola Posadas

Theses and Dissertations

Yeast probiotics and paraprobiotics, live and inactivated yeast cells, respectively, improve health and performance of livestock by stabilizing the intestinal microbial community. They have also been used for infection prevention and treatment. Despite much research already conducted, the mechanism of direct antagonism, or adhesion of bacteria to the probiotic/paraprobiotic, is under characterized. Additionally, it is unknown which probiotic/paraprobiotic is optimal to use for specific infections. The interactions between the yeast and certain pathogens were analyzed qualitatively with scanning electron microscopy (SEM) and quantitatively with membrane filtration assays. Gram-positive bacteria were found to exhibit specificity under SEM. Through membrane filtration, Listeria …


Influence Of Market Setting And Time Of Purchase On Counts Of Aerobic Bacteria, Escherichia Coli, And Coliform And Prevalence Of Salmonella And Listeria In Beef, Pork, And Chicken In Vietnam, April Kathleen Mccain Dec 2015

Influence Of Market Setting And Time Of Purchase On Counts Of Aerobic Bacteria, Escherichia Coli, And Coliform And Prevalence Of Salmonella And Listeria In Beef, Pork, And Chicken In Vietnam, April Kathleen Mccain

Theses and Dissertations

The objective of this study was to determine the influence of market type and sampling time on Salmonella and Listeria prevalence and microbiological quality of 540 beef, pork, and whole chicken samples collected in 6 supermarkets (SM), 6 indoor markets (IM), and 6 open markets (OM) at opening (T0) and 4 h after the opening (T4) in Vietnam. Salmonella and Listeria prevalence ranged from 30.4 to 71.0% and 56.6 to 99.9 %, respectively, in beef, pork, and chicken in Vietnam. Aerobic bacteria counts ranged from 10.5 to 11.6 log CFU/g, whereas, E. coli and coliform counts ranged from 7.2 to …


Construction Of Class I Hla-Binding Peptidome, Heng Luo Dec 2015

Construction Of Class I Hla-Binding Peptidome, Heng Luo

Theses and Dissertations

The human leukocyte antigens (HLAs) can capture endogenous or exogenous peptides and set up a cascade which results in immune activation to fight a pathogen or sometimes to trigger autoimmune diseases or adverse drug reactions. Understanding HLA-peptide binding is essential for the development of vaccines and protein therapies, the identification of methods to prevent autoimmune diseases and the prediction of adverse drug reactions. Using an in silico approach we generated a 9-mer peptidome for Class I HLAs from the human proteome and harvested experimental HLA-peptide binding data from a variety of databases. Unfortunately, many peptides in the peptidome do not …


Computational Analysis Of The Sir Mathematical Model For The Dengue Fever, Joseph Phillip Diaz Dec 2015

Computational Analysis Of The Sir Mathematical Model For The Dengue Fever, Joseph Phillip Diaz

Theses and Dissertations

Dengue fever is a disease affecting people in more than 100 countries. Here we consider a host and vector model for the transmission of dengue fever. This SIR model consists of three compartments of susceptible, infective and removed for host (human) and two compartments of susceptible and infective for vector (dengue mosquitos). These five compartments yield five coupled nonlinear ordinary differential equations (ODEs). After non-dimensionalization, we have a system of three nonlinear ODEs. Reproductive number and two equilibrium points are calculated for various cases. Simulation is carried out for susceptible, infective and removed and the results are presented in graphical …


Examination Of The Chagas Disease Vector, Triatoma Gerstackeri, In The Lower Rio Grande Valley, Alfredo Flores Dec 2015

Examination Of The Chagas Disease Vector, Triatoma Gerstackeri, In The Lower Rio Grande Valley, Alfredo Flores

Theses and Dissertations

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, which is carried by an insect vector of the family Reduviidae, and of the subfamily Triatomina. The species Triatoma gerstaeckeri is identified as the primary vector of T. cruzi within the Rio Grande Valley. Species of Triatoma gerstaeckeri were trapped in La Sal del Rey National Refuge in 2012 and 2013.

Data indicates a seasonal dispersal pattern of activity for T. gerstaeckeri. Optimal time of capture was between 1-2 hours after sunset. Different methods were utilized to determine the best combination of lures. Results indicate that the UV-light alone is …


Institutional Factors Influencing African-American Male Involvement In Undergraduate Student Organizations, John Mark Davenport Oct 2015

Institutional Factors Influencing African-American Male Involvement In Undergraduate Student Organizations, John Mark Davenport

Theses and Dissertations

Students attending colleges and universities who have purposeful opportunities to interact with peers and faculty about educational matters and who are challenged with consistent encouragement report higher levels of satisfaction with their collegiate experience and have higher persistence rates than students who do not receive these opportunities (Kuh et al., 1991; Pascarella & Terenzini, 1991; Schroeder & Mable, 1994). In higher education, African-American males are neither retained from admission through graduation at a rate comparable to majority students nor African-American women (AASCU, 1988; ACE, 2008; Harper, 2012). In this study I set out to determine which institutional factors influence African-American …


Mass Spectrometry Based Proteomics And Lipidomics Studies, Huan Kang Oct 2015

Mass Spectrometry Based Proteomics And Lipidomics Studies, Huan Kang

Theses and Dissertations

Mass spectrometry has emerged as having a vital role in various applications to biochemical fields. In this thesis, we have utilized a variety of mass spectrometry techniques for both bacteriophage proteomics and colostrum and milk lipidomics studies. Our first study was the proteome characterization of Great Salt Lake bacteriophage NS01 with SDS-PAGE GEL to separate the viral proteins and high performance liquid chromatography (HPLC) coupled with an LTQ Orbitrap to identify the proteins after in-gel digestion. In this project, we have successfully identified 11 proteins with high confidence, p-values < 0.01, including coat protein gp88 with a coverage of 91% and tail protein gp86 with a coverage of 40.96%, which facilitated the classification of NS01 as a T7-like phage. Our second study was the discovery of colostrum and milk biomarkers that can be used to predict the likelihood of development of production-related metabolic diseases (PRMDs) in dairy cows through a lipidomics approach. In this study, an electrospray ionization, time-of-flight mass spectrometer was applied to lipid profiling, quantification and significant biomolecule selection. A Q-Star quadrupole, orthogonal time-of-flight mass spectrometer and an Agilent 6530 accurate-mass quadrupole/time-of flight mass spectrometer were both used for lipid biomarker fragmentation and identification. According to linear discriminative statistical modeling, three panels of biomarkers were defined. A combination of 2 milk lipid predictors, including DG18:0/18:0 and TG 18:0/18:0/18:1, provided PRMD predictions with 75.0% sensitivity at 90.0% specificity. A combination of 3 colostrum lipid predictors, including TG16:0/18:1/18:3, DG16:0/16:0 and C40H60NO, provided PRMD prediction with 90.0% sensitivity at …


Vaccination Policies Of Utah Family Practice Clinics, Levi R. Kohler Sep 2015

Vaccination Policies Of Utah Family Practice Clinics, Levi R. Kohler

Theses and Dissertations

The purpose of this study was to collect information regarding healthcare worker (HCW) vaccination policies in Utah family practice clinics. Data sources: The study was conducted in Utah family practice clinics in the most densely populated counties in the state and was a cross-sectional descriptive design. Data were collected from 155 family practice clinic managers. Analyses included frequencies and percentages for quantitative items and a content analysis for open-ended items. Conclusions: HCWs are employed in environments where infectious diseases can be easily spread from person to person, thus, vaccinations can be instrumental in protecting the health of HCWs and patients …


The Effect Of Oxygen On Bile Resistance In Listeria Monocytogenes, Morgan Layne Wright Aug 2015

The Effect Of Oxygen On Bile Resistance In Listeria Monocytogenes, Morgan Layne Wright

Theses and Dissertations

Listeria monocytogenes is a Gram-positive facultative anaerobe that is the causative agent of the disease listeriosis and is responsible for nearly 20% of all food-related deaths in the United States. The ability of this bacterium to cause infections is proposed to correlate to its ability to resist the bactericidal properties of bile acids found in bile. Bile resistance mechanisms have exhibited increased activity under anaerobic conditions. Therefore, we hypothesized that limited oxygen could enhance the bile resistance of L. monocytogenes. Upon survival analysis, viability for virulent strains F2365, EGD-e, and 10403S increased upon 10% porcine bile extract under anaerobic conditions. …


The Impact Of Pyruvate Oxidase (Spxb) On The Release Of The Toxin Pneumolysin In Streptococcus Pneumoniae, Joseph Colby Bryant Aug 2015

The Impact Of Pyruvate Oxidase (Spxb) On The Release Of The Toxin Pneumolysin In Streptococcus Pneumoniae, Joseph Colby Bryant

Theses and Dissertations

Streptococcus pneumoniae (pneumococcus) is a major human pathogen and commensal organism of the nasopharynx. A major virulence factor of the pneumococcus is the cholesterol dependent, pore forming cytolysin pneumolysin. This toxin acts extracellularly, but the mechanism of release has not been well elucidated. Despite being a catalase negative organism, the pneumococcus produces up to millimolar concentrations of hydrogen peroxide through the activity of pyruvate oxidase. In all strains analyzed, deletion of the pyruvate oxidase gene yielded a significant reduction in the amount of PLY observed in the supernatant via western blot. A single strain, WU2 was also observed to have …