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A Case-Study Approach To Investigate Transmission, Co-Infection, And Clinical Sequelae During Epidemics Of Dengue And Ebola Virus Disease, Jennifer Elizabeth Giovanni

LSU Doctoral Dissertations

From within their ecologic niches, zoonotic viruses emerge from animal reservoirs into the edges and centers of human habitation to exploit opportunities for unabated transmission within immunologically–naïve populations. Our understanding of where, in whom, and how these viruses emerge is under direct challenge, driving the evolution of modern infectious disease epidemiology within a rapidly-connected global community. The studies presented herein are based on analyses of both aggregate and case-level data, which, we argue, provide unique insight into the complexities of transmission, co-infection, and clinical sequelae occurring within, and arising from, epidemics of emerging zoonotic viruses. In Chapter II, we investigate …

Kinetics Of Hiv-1 Uncoating In C20 Microglial Cells, Melanie Anne Taylor

Graduate Theses/Dissertations

Uncoating is a poorly understood yet required step of HIV-1 replication that is defined as the disassembly of the viral capsid structure. The goal of this project is to characterize uncoating in C20 microglial cells. These cells are a natural target of HIV-1 that are infected to establish latent viral reservoirs and HIV-associated neurological disorders. A stable C20 cell line that expresses TRIM-CypA was established to study the kinetics of uncoating with the CsA washout assay. The expression of TRIM-CypA was confirmed by western blot and the functionality of the protein was confirmed by a viral infectivity assay. Using this …

See The Forest For The Leaves: Foliar Fungal Community Composition And Volatile Organic Compound Production, Joshua Copeland

Master's Theses

Endophytes are microbes that live within plants without causing detectable illness. These microorganisms can emit volatile organic compounds (VOCs), airborne signaling molecules that can significantly affect plant growth. Despite the prevalence of endophytes and their VOCs, little is known about these factors important to plant health. With this in mind I isolated fungal endophytes from leaves of Populus trichocarpa and Populus fremontii, tree species with economic and environmental uses, to determine if endophyte communities are reserved between the closely related tree species and over seasons. Surface sterilized leaf fragments were plated onto malt extract agar and the resulting fungi were …

Characterization Of Bacterial Isolates Obtained From Commercial Poultry Feed And Retail Food Using Whole Genome Sequence Analysis And Selected Biochemical Tests, Elena George Olson

Electronic Theses & Dissertations

The goals of this study is two-fold. The first part investigates bacterial isolates from commercial poultry feed and the second part deals with bacterial isolates recovered from retail food. In order to reduce pathogen contamination in poultry products identification of overall microbial populations in poultry production processing steps have always been considered an important monitoring tool for assessing sanitizer effectiveness and the corresponding responses of bacteria load levels on poultry carcasses. Bacterial isolates recovered from corn-based chicken feed were purified on aerobic plate count agar and eleven morphologically different colonies were selected for whole genome sequencing. In this part, the …

Development Of A Long-Acting Nanoformulation Of Dolutegravir For Prevention And Treatment Of Hiv-1 Infection, Brady Sillman

Theses & Dissertations

Dolutegravir (DTG) is a potent human immunodeficiency virus type 1 (HIV-1) integrase strand-transfer inhibitor (INSTI) with a high barrier to viral drug resistance. However, opportunities to improve its profile abound. These include extending the drug’s apparent half-life, increasing penetrance to “putative” viral reservoirs, and reducing inherent toxicities. These highlight, in part, the need for long-acting, slow effective release antiretroviral therapy (LASER ART) delivery schemes. A long-acting (LA) DTG was made by synthesizing a hydrophobic and lipophilic prodrug encased with poloxamer (P407) surfactant. This modified DTG (MDTG) reduced systemic metabolism and polarity, increased lipophilicity and membrane permeability, improved encapsulation, and formed …

Prevalence Of Aggregatibacter Actinomycetemcomitans And Fusobacterium Nucleatum Among Clinical Orthodontic Saliva Samples, Jason Robert Klingler

UNLV Theses, Dissertations, Professional Papers, and Capstones

Changes to the oral microflora occur when there are shifts in the levels of the numerous bacterial species. Changes in bacterial load occur in health, disease, and dental treatments such as orthodontics and can be detected through saliva. Many studies dealing with saliva have centered around detecting bacteria known for correlation with chronic periodontitis and caries. Fewer have focused on bacterial species that contribute to microbial shifts not strictly correlated with disease. Measuring the degree of disease progression or future susceptibility is not always possible with traditional clinical parameters alone.

Aggregatibacter actinomycetemcomitans (AA) is a bacterial strain that serves as …

Challenging The Paradigm Of Clinical Triazole Resistance In Aspergillus Fumigatus, Jeffrey Michael Rybak

Theses and Dissertations (ETD)

Invasive aspergillosis is a leading cause of morbidity and mortality among immunocompromised populations and is predicted to cause more than 200,000 life- threatening infections each year. Aspergillus fumigatus is the most prevalent pathogen isolated from patients with invasive aspergillosis, accounting for more than 60% of all cases. Currently, the only antifungal agents available with consistent activity against A. fumigatus are the mold-active triazoles and amphotericin B, of which the triazoles commonly represent both front-line and salvage therapeutic options. Unfortunately, the treatment of infections caused by A. fumigatus has recently been further complicated by the global emergence of triazole resistance among …

Isolation, Analysis, And Partial Characterization Of An Inhibitor Of Neisseria Gonorrhoeae, Natania Paul

Undergraduate Honors Theses

There is an emerging threat of Neisseria gonorrhoeae strains that are resistant to all antibiotics. Because of this, the purpose of this research is to isolate, analyze, and partially characterize a new inhibitor(s) of N. gonorrhoeae. Since there is an unknown molecule secreted by Candida albicans that inhibits N. gonorrhoeae, this molecule can be partially characterized using ¹H NMR Spectroscopy to assist in the development of a new antibiotic compound. It was hypothesized that quorum-sensing molecules, trans, trans- farnesol, tyrosol, phenylethyl alcohol, and tryptophol, could be possible candidates for the inhibitor. Because of this, ¹H …

Development And Evaluation Of A One-Step Multiplex Real-Time Taqman® Rt-Qpcr Assay For The Detection And Genotyping Of Equine G3 And G14 Rotaviruses In Fecal Samples, Mariano Carossino, Maria E. Barrandeguy, Erdal Erol, Yanqiu Li, Udeni B. R. Balasuriya

Veterinary Science Faculty Publications

Background: Equine rotavirus A (ERVA) is the leading cause of diarrhea in neonatal foals and has a negative impact on equine breeding enterprises worldwide. Among ERVA strains infecting foals, the genotypes G3P[12] and G14P[12] are the most prevalent, while infections by strains with other genomic arrangements are infrequent. The identification of circulating strains of ERVA is critical for diagnostic and surveillance purposes, as well as to understand their molecular epidemiology. Current genotyping methods available for ERVA and rotaviruses affecting other animal species rely on Sanger sequencing and are significantly time-consuming, costly and labor intensive. Here, we developed the first one-step …

Iron-Containing Nanoparticles For The Treatment Of Chrionic Biofilm Infections In Cystic Fibrosis, Leisha M. A. Martin

Nanoscience and Microsystems ETDs

Cystic fibrosis (CF) is the most common genetic disease resulting in the morbidity and mortality of Caucasian children and adults worldwide. Due to a genetic mutation resulting in malfunction of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, CF patients produce highly viscous mucus in their respiratory tract. This leads to impairment of the mucociliary clearance of inhaled microbes. In addition to reduced microbial clearance, anoxic environmental conditions in the lungs promote biofilm-mode growth of the pathogenic bacterial species Pseudomonas aeruginosa. Chronic infections of P. aeruginosa begin in early childhood and typically persist until respiratory failure and death result. The …

Lipoarabinomannan From Mycobacterium Smegmatis Stimulates An Inflammatory Response In Raw 264.7 Murine Macrophages, Aysha Zaman

Student Scholar Showcase

Macrophages are a key leukocyte in defense against Mycobacterium tuberculosis infection. The precise mechanism by which M. tuberculosis evades host macrophage defenses remains unknown, so understanding how macrophages interact with cell wall components of mycobacteria is critical. Lipoarabinomannan (LAM) is a glycolipid Toll-like receptor-2 (TLR-2) ligand found on the cell wall of mycobacteria, and is thought to contribute to the cell wall structural integrity. When LAM binds to TLR on host leukocytes, this activates cellular responses and phagocytosis by host macrophages. Nitric oxide production can be used as a measure of inflammatory response and can be evaluated via nitrite response …

Human Gut Microbiome, Enrico José Aveiro Johannsen, Mandy Peak

Posters

The human gut microbiome has been an area of interest for researchers due to its established link with human metabolism, nutrition, physiology, and immune functions. The research presented further investigates the microbiome to better understand it. Stools from two healthy young African males and a French obese individual were analyzed using MALDI-TOF MS and the enrichment culture technique. For the identification of bacterial species metagenomics, genomics, and culturomics were used. The results showed a much broader biodiversity in the human gut than previously predicted, as well as better results when using culturomics for measuring biodiversity in large-scale isolation.

Near-Complete Genome Sequences Of Vesicular Stomatitis Virus Indiana Laboratory Strains Hr And T1026r1 And Plaque Isolates 22-20 And 22-25, Thomas M. Russell, Evan E. Santo, Lisa Golebiewski, Nathan S. Haseley, Maureen Ferran

Articles

We report four near-complete genome sequences of vesicular stomatitis virus (VSV) Indiana obtained with Sanger and Illumina next-generation sequencing, namely, laboratory strains HR (heat resistant) and T1026R1 and isolates 22-20 and 22-25. Previously, only the M gene of these viruses had been sequenced, and these sequences were not deposited in GenBank.

Streptococcus Agalactiae Strains With Chromosomal Deletions Evade Detection With Molecular Methods, Isabella A. Tickler, Fred C. Tenover, Scott Dewell, Victoria M. Le, Rachel N. Blackman, Richard V. Goering, Amy E. Rogers, Heather Piwonka, Brittney D. Jung-Hynes, Derrick J. Chen, Michael J. Loeffelholz, Devasena Gnanashanmugam, Ellen Jo Baron

Biology Faculty Publications

Surveillance of circulating microbial populations is critical for monitoring the performance of a molecular diagnostic test. In this study, we characterized 31 isolates of Streptococcus agalactiae (group B Streptococcus [GBS]) from several geographic locations in the United States and Ireland that contain deletions in or adjacent to the region of the chromosome that encodes the hemolysin gene cfb, the region targeted by the Xpert GBS and GBS LB assays. PCR-negative, culture-positive isolates were recognized during verification studies of the Xpert GBS assay in 12 laboratories between 2012 and 2018. Whole-genome sequencing of 15 GBS isolates from 11 laboratories revealed …

Arthropod Organic Anion Transporting Polypeptides In Tick-Borne Bacterial And Viral Infections, Vikas Kumar Taank

Biomedical Sciences Theses & Dissertations

Vector-borne diseases (VBDs) are human illness transmitted by an arthropod vector. World Health Organization (WHO) estimates that VBD has a huge impact worldwide that is responsible for affecting a billion people and causes 700,000 deaths annually. In recent years, there has been a continuous increase in the incidences of tick-borne diseases such as Lyme diseases and human anaplasmosis as reported by Center for Disease Control and Prevention. Very few reliable VBD control strategies have emerged till now. Transmission-blocking vaccines can provide effective management of VBDs but requires identification and characterization of novel vector-pathogen conserved molecules that play a significant role …

Effect Of Environmental Factors And Residual Sanitizers On Survival And Attachment Of Indicator Organism And Human Pathogens On Fresh Produce, Vijay Singh Chhetri

LSU Doctoral Dissertations

A comprehensive understanding of the behavior of microbial contaminants on produce surfaces in agricultural farms and during post-harvest activities is essential for the development of produce safety risk management strategies. Our studies investigated the survival and the attachment of E. coli on watermelon surfaces in agricultural settings with different levels of vegetation, and the effect of residual sanitizers on the survival and the attachment of E. coli O157: H7 and L. monocytogenes on spinach leaves. The attachment strength (S_R) of the E. coli cells on watermelon surfaces significantly increased (P<0.05) from 0.04 to 0.99 in the first 24 h, which was primarily due to the decrease in loosely attached population, given that the population of strongly attached cells was constant. The daily die-off rate of E. coli ranged from -0.12 …

Serum Amyloid P Component Binds Fungal Surface Amyloid And Decreases Human Macrophage Phagocytosis And Secretion Of Inflammatory Cytokines, Nicole E. Behrens, Peter N. Lipke, Darrell Pilling, Richard H. Gomer, Stephen A. Klotz

Publications and Research

In patients with invasive fungal diseases, there is often little cellular inflammatory response. We tested the idea that binding of the human constitutive plasma protein serum amyloid P component (SAP) (also called PTX2) to Candida albicans dampens the innate immune response to this fungus. Many pathogenic fungi have cell surface amyloid-like structures important for adhesion and biofilm formation. Human SAP bound to fungi that expressed functional cell surface amyloid, but SAP had minimal binding to fungi with reduced expression of cell surface amyloid. In the absence of SAP, phagocytosis of fungi by human macrophages was potentiated by expression of amyloid …

A Human Papillomavirus-Independent Cervical Cancer Animal Model Reveals Unconventional Mechanisms Of Cervical Carcinogenesis, Chunbo He, Xiangmin Lv, Cong Huang, Peter C. Angeletti, Guohua Hua, Jixin Dong, Jin Zhou, Zhengfeng Wang, Bowen Ma, Xingcheng Chen, Paul F. Lambert, Bo R. Rueda, John S. Davis, Cheng Wang

Nebraska Center for Virology: Faculty Publications

HPV infections are common in healthy women and only rarely cause cervical cancer, suggesting that individual genetic susceptibility may play a critical role in the establishment of persistent HPV infection and the development of cervical cancer. Here, we provide convincing in vitro and in vivo evidence showing that differential expression and activation of YAP1 oncogene determine individual susceptibility to HPV infection and cervical carcinogenesis. We found that hyperactivation of YAP1 in mouse cervical epithelium was sufficient to induce invasive cervical cancer. Cervical epithelial cell-specific HPV16 E6/E7 and YAP1 double-knockin mouse model demonstrated that high-risk HPV synergized with hyperactivated YAP1 to …

Targeted Therapy For The Future: The Use Of Novel Antimicrobial Peptides Against P. Aeurginosa, Matthew Froid

UNO Student Research and Creative Activity Fair

Pathogenic bacteria, such as the gram-negative bacterium Pseudomonas aeruginosa, are becoming resistant to our current arsenal of antibiotics at an alarming rate. P. aeruginosa is a leading cause of nosocomial acquired infections and is a primary co-morbidity in patients with compromised immune systems. One potential source of new antibiotic agents is antimicrobial peptides. Antimicrobial peptides (AMPs) are small proteins, and some have shown a high degree of efficacy and broad-spectrum activity against both Gram-positive and Gram-negative bacteria. An experimental AMP that has been developed by Dr. Wang at UNMC, DASamp2, has shown to be effective against virulent bacteria, including P. …

Diversity Of Resistance Mechanisms In Carbapenem-Resistant Enterobacteriaceae At A Health Care System In Northern California, From 2013 To 2016, Fiona Senchyna, Rajiv L. Gaur, Johanna Sandlund, Cynthia Truong, Guillaume Tremintin, Dietmar Kültz, Carlos A. Gomez, Fiona B. Tamburini, Tessa Andermann, Ami Bhatt, Isabella A. Tickler, Nancy Watz, Indre Budvytiene, Gongyi Shi, Fred C. Tenover, Niaz Banaei

Biology Faculty Publications

The mechanism of resistance in carbapenem-resistant Enterobacteriaceae (CRE) has therapeutic implications. We comprehensively characterized emerging mechanisms of resistance in CRE between 2013 and 2016 at a health system in Northern California. A total of 38.7% (24/62) of CRE isolates were carbapenemase gene-positive, comprising 25.0% (6/24) blaOXA-48 like, 20.8% (5/24) bla_KPC, 20.8% (5/24) bla_NDM, 20.8% (5/24) bla_SME, 8.3% (2/24) bla_IMP, and 4.2% (1/24) bla_VIM. Between carbapenemases and porin loss, the resistance mechanism was identified in 95.2% (59/62) of CRE isolates. Isolates expressing bla_KPC were 100% susceptible to ceftazidime–avibactam, meropenem–vaborbactam, …

Host Lipids In Positive-Strand Rna Virus Genome Replication, Zhenlu Zhang, Guijuan He, Natalie A. Filipowicz, Glenn Randall, George A. Belov, Benjamin G. Kopek, Xiaofeng Wang

Faculty Publications

Membrane association is a hallmark of the genome replication of positive-strand RNA viruses [(+)RNA viruses]. All well-studied (+)RNA viruses remodel host membranes and lipid metabolism through orchestrated virus-host interactions to create a suitable microenvironment to survive and thrive in host cells. Recent research has shown that host lipids, as major components of cellular membranes, play key roles in the replication of multiple (+)RNA viruses. This review focuses on how (+)RNA viruses manipulate host lipid synthesis and metabolism to facilitate their genomic RNA replication, and how interference with the cellular lipid metabolism affects viral replication.

Yap1-Lats2 Feedback Loop Dictates Senescent Or Malignant Cell Fate To Maintain Tissue Homeostasis, Chunbo He, Xiangmin Lv, Cong Huang, Guohua Hua, Bowen Ma, Xingcheng Chen, Peter C. Angeletti, Jixin Dong, Jin Zhou, Zhengfeng Wang, Bo R. Rueda, John S. Davis, Cheng Wang

Nebraska Center for Virology: Faculty Publications

Dysfunction of the homeostasis-maintaining systems in specific cell types or tissues renders the organism susceptible to a range of diseases, including cancers. One of the emerging mechanisms for maintaining tissue homeostasis is cellular senescence. Here, we report that the Hippo pathway plays a critical role in controlling the fate of ovarian cells. Hyperactivation of Yes-associated protein 1 (YAP1), the major effector of the Hippo pathway, induces senescence in cultured primary human ovarian surface epithelial cells (hOSEs). Large tumor suppressor 2 (LATS2), the primary upstream negative regulator of YAP1, is elevated in both YAP1-induced and natural replicative-triggered senescence. Deletion of LATS2 …

Characterization Of Immunomodulatory Microbial Factors In Medicinal Plants, Kriti Kalpana

Dissertations, Theses, and Capstone Projects

Medicinal plants are one of the biggest sources of natural products with therapeutic importance. There are currently over 28,000 plants with putative medicinal values. Plant-derived compounds have been explored extensively for various biological activities ranging from anti-cancer, immune-boosting to anti-inflammatory and anti-oxidant. Some of the most important therapeutic agents are of plant-origin, such as paclitaxel from Pacific yew (Taxus brevifolia) and artemisinin from qinghao su (a Chinese medicinal herb; a.k.a. Artemisia annua) to name a few.

The study presented in this thesis started out as classical pharmacognosy research, which focused on the identification of immunostimulatory factors in …

Enhancement Of Immune Response Against Bordetella Spp. By Disrupting Immunomodulation, Monica C. Gestal, Laura K. Howard, Kalyan Dewan, Hannah M. Johnson, Mariette Barbier, Clare Bryant, Illiassou Hamidou Soumana, Israel Rivera, Bodo Lina, Uriel Blas-Machado, Eric T. Harvill

Faculty & Staff Scholarship

Well-adapted pathogens must evade clearance by the host immune system and the study of how they do this has revealed myriad complex strategies and mechanisms. Classical bordetellae are very closely related subspecies that are known to modulate adaptive immunity in a variety of ways, permitting them to either persist for life or repeatedly infect the same host. Exploring the hypothesis that exposure to immune cells would cause bordetellae to induce expression of important immunomodulatory mechanisms, we identified a putative regulator of an immunomodulatory pathway. The deletion of btrS in B. bronchiseptica did not affect colonization or initial growth in the …

Genetic Study Of Checkpoint Defects Of The Mus81-1 Mutant In The Fission Yeast Schizosaccharomyces Pombe, Darlington Osei Abrefa

Browse all Theses and Dissertations

In response to various perturbations of DNA replication, the DNA replication checkpoint is activated in eukaryotes to stimulate a cascade of cellular responses that are crucial for maintaining genome stability and cell survival. Defects in the checkpoint pathway result in mutations and genome instability, which is a hallmark for cancers. This study used a genetic approach to identify a mutation in the MMS (methyl methanesulfonate) and UV-sensitive protein Mus81, a DNA repair enzyme that resolves aberrant DNA structures through the homologous recombination pathway. We show that a single missense mutation, identified in fission yeast mus81-1, causes moderate reduction in the …

Design And Characterization Of A Consensus Hemagglutinin Vaccine Immunogen Against H3 Influenza A Viruses Of Swine, Haiyan Sun, Jung-Hyang Sur, Sarah Vitosh-Sillman, David J. Steffen, Hiep Vu

Nebraska Center for Virology: Faculty Publications

The substantial genetic diversity exhibited by influenza A viruses of swine (IAV-S) represents the main challenge for the development of a broadly protective vaccine against this important pathogen. The consensus vaccine immunogen has proven an effective vaccinology approach to overcome the extraordinary genetic diversity of RNA viruses. In this project, we sought to determine if a consensus IAV-S hemagglutinin (HA) immunogen would elicit broadly protective immunity in pigs. To address this question, a consensus HA gene (designated H3-CON.1) was generated from a set of 1,112 H3 sequences of IAV-S recorded in GenBank from 2011 to 2015. The consensus HA gene …

Humboldt Journal Of Microbiology: Volume 20, Number 1- May 2019, Press Humboldt

Humboldt Journal of Microbiology

No abstract provided.

Probiotics: Reiterating What They Are And What They Are Not, Azza A. Gadir, Raja Dhir, Gregor Reid

Microbiology & Immunology Publications

It has been over seventeen years since the scientific definition of probiotics was crafted, along with guidelines ensuring the appropriate use of the term. This definition is now used globally, yet on a consistent basis scientists, media and industry misrepresent probiotics or make generalized statements that illustrate a misunderstanding of their utility and limitations. The rate of discovery of novel organisms with potentially therapeutic benefit for both human and environmental health is progressing at an unprecedented rate. However, the term “probiotic” is often misapplied to describe any microbe with plausible therapeutic utility in the human host. It is argued that …

Enhanced Expression Of Receptor Tyrosine Kinase Mer (Mertk) On Socs3-Treated Polarized Raw 264.7 Anti-Inflammatory M2c Macrophages, Sankhadip Bhadra

Browse all Theses and Dissertations

Macrophages are phagocytic cells located in tissues, organs and even circulated within our body as white blood cells. They are critical in detecting tissue damage and infection. Resident tissue macrophages initiate the signals for inflammation recruiting neutrophils and blood monocytes which mature into macrophages at sites of infection and in the resolution of inflammation. Based on the local cytokine milieu in tissue sites, macrophages may be polarized into pro-inflammatory M1 or anti-inflammatory M2 phenotypes. Receptor tyrosine kinase Mer (MERTK) helps in clearing dead neutrophils and other apoptotic cells from damaged tissue sites preventing chronic inflammation and autoimmune disorders. MERTK aids …

Host Restriction Factors In The Replication Of Tombusviruses: From Rna Helicases To Nucleocytoplasmic Shuttling, Cheng-Yu Wu

Theses and Dissertations--Plant Pathology

Positive-stranded (+)RNA viruses replicate inside cells and depend on many cellular factors to complete their infection cycle. In the meanwhile, (+)RNA viruses face the host innate immunity, such as cell-intrinsic restriction factors that could block virus replication.

Firstly, I have established that the plant DDX17-like RH30 DEAD-box helicase conducts strong inhibitory function on tombusvirus replication when expressed in plants and yeast surrogate host. This study demonstrates that RH30 blocks the assembly of viral replicase complex, the activation of RNA-dependent RNA polymerase function of p92pol and viral RNA template recruitment.

In addition, the features rendering the abundant plant DEAD-box helicases either …