Organisms Commons^™

Use Of High-Throughput Phenomics With And Without Fungicide As A Wheat Breeding Tool, Gerardo Ivan Rivera Collazo

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Wheat (Triticum aestivum) is an important food staple for many countries around the world and current consumption and production data demonstrate a production deficit. Breeders are challenged to help close this gap in production by selecting better cultivars with improved yields. Several methods aim to accelerate the breeding process to reduce the time required for releasing an elite variety. One of the main breeding bottlenecks is the lack of fast and reliable phenotypic data acquisition that could dissect physiological and morphological plant data. High-throughput remote sensing could have the potential to reduce this bottleneck by streamlining data acquisition, …

Overcoming Vaccine-Associated Enhanced Respiratory Disease In Swine Flu With Lipid Nanoparticle-Dna Technology, The Nguyen

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

The two primary challenges in developing vaccines against swine influenza A virus (IAV-S) are the continuous viral evolution and vaccine-associated enhanced respiratory disease (VAERD). Current vaccine strategies share a common limitation: the significant time required for licensing updated vaccines. Moreover, the strain selection for vaccine updates depends entirely on predictions, raising the risk that chosen strains may not match circulating viruses. Such mismatches not only reduce vaccine efficacy but also risk exacerbating disease severity through VAERD. Here, in this thesis, we developed and evaluated a novel DNA-based vaccine platform designed to address the need for rapid updates in response to …

Implications Of Type Iv Pilus Retraction For Dna Uptake By Acinetobacter Baumannii, Yafan Yu

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Horizontal gene transfer (HGT) via natural competence allows bacteria to incorporate extracellular DNA (eDNA) into their genomes, facilitating genetic diversity and adaptation. In Acinetobacter species, natural competence depends on DNA binding and uptake mediated by type IV pili (T4P). T4P are dynamic extracellular filaments composed primarily of the major pilin subunit PilA, along with a few minor subunits. T4P drive a range of cellular functions including twitching motility, biofilm formation, and DNA uptake, with some functions dependent on pilus retraction and others not. However, how Acinetobacter T4P bind DNA and how T4P/eDNA interactions impact biofilm formation remain unclear. Here, I …

Host Genetics Role In Viral Disease Susceptibility, Christian Willis Eaton

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Viruses and their hosts exist in an evolutionary arms race, with evolutionary promotion of host genetic-based defense mechanisms and evolution of virus genetic-based mechanisms to overcome host defenses. Viruses are capable of much more rapid evolution and adaptation than their hosts, often leading to the use of host cellular mechanisms to promote viral infection and replication. In this study, we describe the generation of a detection assay for atypical porcine pestivirus (APPV), designed to target the viral 5’ UTR, a region of the viral genome which sees less mutations than the protein coding regions. This assay was generated to be …

Inactivation Of E. Faecium Nrrl B-2354 In Whole Black Pepper By Fluidization With Hydrogen Peroxide Vapor, Daniela Segura

Department of Food Science and Technology: Master of Science with Project Option

This study evaluated Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella inactivation in black peppercorns treated with hydrogen peroxide (HP) vapor via fluidization. The selected parameter for dwell temperature was 60ºC for 60 minutes. The reduction of both Salmonella and E. faecium, along with changes in water activity, color, and residual hydrogen peroxide, were measured before, immediately after treatment and at 24 and 48 hours post-treatment. Results showed that E. faecium exhibited a significantly greater reduction (4.63 ± 0.55 log CFU/g) compared to Salmonella (2.94 ± 0.16 log CFU/g) (p < 0.05), making E. faecium unsuitable as …

Dental Disparities: An Analysis Of Dental Caries Risk Factors Promoting Disparities Between Rural And Urban Communities In Nebraska, Nick Lounsbery

Honors Program: Senior Projects (Public)

The prevalence of dental caries in the United States remains a public health concern, as it is one of the most common chronic conditions across people of all ages. Research shows that preventative measures including brushing, fluoridated water, and regular checkups are effective strategies to mitigate tooth decay. However, there appears to be a divide between rural and urban populations, as the presence of dental cavities is significantly greater in remote areas in the State of Nebraska. Research methods used in this analysis included analyzing accredited academic literature to illustrate how cavities form from a biochemical perspective. Research methods also …

Identification Of Benzothiophene-Derived Inhibitors Of Flaviviruses By Targeting Rna-Dependent Rna Polymerase, Leah Liu Wang, Shazeed-Ul Karim, Aidan Hand, Ryan Brunkhorst, Mackenna Petersen, Sarah Altam, Yi Liu, Luwen Zhang, Fengwei Bai, Shi-Hua Xiang

School of Biological Sciences: Faculty Publications

Flaviviruses such as Dengue, West Nile, and Zika viruses are mosquito-borne RNA viruses that can cause serious diseases in humans. To develop effective drugs for treating these viruses’ infections, we create a new approach for developing common or shared drugs that may work for several different viral species of flaviviruses. It is based on the conserved RNA-dependent RNA polymerase (RdRp), which is the key enzyme for viral replication. We built up a common structure of RdRps (POLcon) from their consensus sequence. A conserved Triple-D structural motif was identified at the active site of POLcon that has been used for virtual …

Molecular Detection Of Pathogenic Bacteria In American Dog Ticks (Dermacentor Variabilis) In Brown County, Nebraska, Nicole Messbarger, Darby Carlson, Keith Geluso, Julie Shaffer

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Ticks carry and transmit disease pathogens that cause many human illnesses. Many of these diseases in humans are accompanied by a wide variety of symptoms making tick-borne illnesses often difficult to diagnose. The rate of reported tick-borne illnesses in humans has increased during the past decades in the United States, alongside a rise in concern for public health and safety. In northern Nebraska, the American dog tick (Dermacentor variabilis) is the primary tick encountered by humans and domestic animals in the region. This species is a known vector for spotted fever group (SFG) rickettsioses and tularemia (Francisella …

Candida Albicans Farnesol Synthesis And Secretion, Daniel J. Gutzmann

School of Biological Sciences: Dissertations, Theses, and Student Research

Candida albicans is a polymorphic fungus and opportunistic commensal found primarily in the gastrointestinal and skin of healthy individuals. Several barriers prevent C. albicans from causing disease including a healthy immune system and microbiome. When these barriers become comprised, C. albicans can transition to a pathogen and disseminate through the intestinal mucosa leading to life-threatening bloodstream and invasive infections with mortality rates of up to 64%. Morphogenic plasticity is key to this transition and impacts virulence, adaptation to different host environments, and evasion of host immune responses. One regulator of morphogenesis is farnesol. Farnesol is a secondary metabolite of …

Triticale As A Source Of Resistance To Wheat Streak Mosaic Virus And Triticum Mosaic Virus, Marcos Winicius Goncalves De Souza

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) present a great threat to wheat production in the Great Plains area of the United States due to the loss of photosynthetic area causing reductions in crop yields. Effective control of these viruses is limited to a few available strategies including controlling volunteer wheat and using currently identified resistant genes to both the vector and viruses. While effective, these genes show temperature sensitivity and yield drag, and evidence that the vectors and viruses can overcome them has been found. Thus, new methods of genetic resistance are urgently needed. Field observations …

Assessment Of Foam Decontamination In Tomato Washing Process, Basim M. Alohali

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The work of the dissertation investigated the efficacy of foam-based decontamination treatments to enhance microbial safety in Roma tomatoes, specifically targeting natural microflora and Salmonella contamination. Growing concerns over foodborne illnesses linked to fresh tomatoes and the limitations of conventional decontamination techniques, such as organic matter built-up and limited microbial reduction, are addressed. The primary objectives were to characterize the physiochemical properties of foams formed using various concentrations of Tween 20 (T20) and sodium dodecyl sulfate (SDS) with and without the addition of sodium hypochlorite (NaOCl) and peracetic acid (PAA), compare the efficacy of foam and traditional dump tank (DT) …

Investigating The Abilities Of Potentially Beneficial Bacteria For Increasing Nitrogen-Use Efficiency In Maize, Lexie R. Foster

School of Biological Sciences: Dissertations, Theses, and Student Research

Global agriculture relies heavily on the use of synthetic nitrogen fertilizer to meet the current global food demand. Unfortunately, the average nitrogen-use efficiency (NUE) of maize (Zea mays) is approximately 50 percent. Improving the NUE of maize is essential for meeting the growing global food demand while also decreasing the negative environmental impacts caused by losses of nitrogen fertilizer due to runoff and volatilization. Harnessing the symbiotic relationship between plants and the soil microbiome may be one method for increasing the NUE in crops such as maize. In the present study, a set of potentially beneficial bacterial species …

Exploring Subtype C Hiv-1 Tissue Reservoirs And The Impact Of Cannabis Use In Virally Suppressed African Individuals, Zhou Liu

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Antiretroviral therapy (ART) has dramatically prolonged the lives of people living with HIV (PLWH), but it is not curative as it cannot eliminate integrated HIV-1 proviruses in different tissue reservoirs. Even though subtype C HIV-1 accounts for almost half of global HIV-1 infections, few studies had evaluated HIV-1 reservoirs for this subtype. Many co-factors, including the lifestyle factor cannabis use, have been investigated for their potential effects in HIV-1 infection. However, only limited information exists regarding cannabis’s effects on HIV-1 infections in vivo, and the impact of cannabis use on HIV-1 parenchymal tissue reservoirs is unexplored. This dissertation aims to …

Novel Insights Into The Autoimmune Mechanisms In Coxsackievirus B Infections And Their Prevention By Vaccination, Mahima Theresa Rasquinha

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Coxsackievirus Bs (CVBs) are RNA viruses of the genus Enterovirus belonging to the Picornaviridae family. CVBs commonly infect humans, and multiple CVB types can induce similar diseases such as myocarditis, pancreatitis, and type 1 diabetes (T1D). Although CVB infections can lead to the generation of autoantibodies, their role in disease is poorly defined, and vaccines are not available to prevent or minimize these infections. To fill these gaps, we first analyzed the autoantibody repertoire in mice infected with CVB3 by Phage ImmunoPrecipitation Sequencing (PhIP-Seq) and identified autoantibodies for several novel antigens not previously reported. The data were validated using enzyme-linked …

The Developmental Process For Adenoviral Vectored Canine Influenza Vaccines, Nicholas Jeanjaquet

School of Biological Sciences: Dissertations, Theses, and Student Research

Canine Influenza Virus (CIV) is a recently emerged branch of Influenza A virus that is highly infectious in dogs. The first strain was isolated in 2003, and it has quickly become endemic in areas with dense dog populations, most notably in Asia. The proximity of dogs to humans, along with their potential to serve as mixing vessels for reassortment, raises concern for possible zoonotic transmission and a potential human pandemic. Available vaccines are not frequently updated and struggle to prevent the spread of currently circulating strains. This highlights the need for a new and more effective vaccine. We outline the …

Discovering Novel Polyextremotolerant Fungi And Determining Their Ecological Role Within The Biological Soil Crust Consortium, Erin C. Carr

School of Biological Sciences: Dissertations, Theses, and Student Research

The ecological niche of polyextremotolerant fungi within oligotrophic ecosystems such as biological soil crusts has not yet been determined. These fungi persist in locations where nutrients are depleted while simultaneously surrounded by autotrophic microbes such as algae and cyanobacteria. Yet it has not been shown that they are engaging in any exchange of nutrients the way lichens do. However, there is seemingly no other way for these fungi to obtain vital nutrients, such as carbon or nitrogen, other than from these microbes. Here we have isolated polyextremotolerant fungi from cold desert biological soil crusts which are a microbial biofilm that …

Evaluation Of Protective Efficacy Of Viral Vector Based Swine Influenza Vaccine And A Method For B Cell Culture For Monoclonal Antibody Generation, Sushmita Kumari

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Influenza A virus of the swine (IAV-S) is an economically important swine pathogen that has the potential to spread to humans, thus posing an ongoing public health concern due to its zoonotic potential. Hemagglutinin (HA), the most abundant viral envelope protein, is known to be the key protective antigen. Anti-HA antibodies alone, have been shown to prevent IAV infection. In this study we evaluated the feasibility of a recombinant tri segmented Pichinde virus (PICV) as a viral vector to deliver IAV-S hemagglutinin antigen in pigs. Four groups of weaned pigs (T01-04) were immunized twice with PBS, rPICV-GFP as a vector …

Host Cell Responses To Zika Virus Infection, Bikash Ranjan Sahoo

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

The re-emergence of Zika virus (ZIKV) in 2015 as a significant human pathogen causing neurological diseases in infants as well as adults is a serious global health concern. A clear understanding of the mechanisms involved in ZIKV replication in infected host cells as well as the host responses to virus infection are keys to the development of therapeutic strategies against ZIKV. Studies conducted in this dissertation demonstrate that ZIKV infection induces the activation of mTOR signaling cascade that promotes viral protein accumulation and infectious progeny production. While both mTORC1 and mTORC2 are essential for ZIKV replication, the observation that depletion …

Development Of Vaccines And Antivirals Against Zika Virus, Aryamav Pattnaik

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

The re-emergence of Zika virus (ZIKV), an arbovirus, poses a major global human health concern because of its ability to cause congenital abnormalities and neurological diseases. While many candidate vaccines and antiviral drugs are in the developmental pipeline, none have been approved for use against ZIKV infection. This dissertation describes the characterization of one vaccine and two antiviral drug candidates against ZIKV infection. A bacterial ferritin-based nanoparticle vaccine, termed zDIII-F, is designed to display multiple copies of ZIKV E protein domain III on its surface. These stable nanoparticles are shown to induce robust antibody-mediated protection against lethal ZIKV infection in …

3d Printing Of Human Microbiome Constituents To Understand Spatial Relationships And Shape Parameters In Bacteriology, Jacques Izard, Teklu Kuru Gerbaba, Shara R. P. Yumul

Department of Food Science and Technology: Faculty Publications

Effective laboratory and classroom demonstration of microbiome size and shape, diversity, and ecological relationships is hampered by a lack of high-resolution, easy-to-use, readily accessible physical or digital models for use in teaching. Three-dimensional (3D) representations are, overall, more effective in communicating visuospatial information, allowing for a better understanding of concepts not directly observable with the unaided eye. Published morphology descriptions and microscopy images were used as the basis for designing 3D digital models, scaled at 20,000×, using computer-aided design software (CAD) and generating printed models of bacteria on mass-market 3D printers. Sixteen models are presented, including rod-shaped, spiral, flask-like, vibroid, …

Covid19 Disease Map, A Computational Knowledge Repository Of Virus–Host Interaction Mechanisms, Marek Ostaszewski, Tomáš Helikar, Bhanwar Lal Puniya, A Host Of Co-Authors, Covid-19 Disease Map Community

Department of Biochemistry: Faculty Publications

We need to effectively combine the knowledge from surging literature with complex datasets to propose mechanistic models of SARS-CoV-2 infection, improving data interpretation and predicting key targets of intervention. Here, we describe a large-scale community effort to build an open access, interoperable and computable repository of COVID-19 molecular mechanisms. The COVID-19 Disease Map (C19DMap) is a graphical, interactive representation of disease-relevant molecular mechanisms linking many knowledge sources. Notably, it is a computational resource for graph-based analyses and disease modelling. To this end, we established a framework of tools, platforms and guidelines necessary for a multifaceted community of biocurators, domain experts, …

Comparisons Of Oral, Intestinal, And Pancreatic Bacterial Microbiomes In Patients With Pancreatic Cancer And Other Gastrointestinal Diseases, Mei Chung, Naisi Zhao, Richard Meier, Devin C. Koestler, Guojun Wu, Erika De Castillo, Bruce J. Paster, Kevin Charpentier, Jacques Izard, Karl T. Kelsey, Dominique S. Michaud

Department of Food Science and Technology: Faculty Publications

Background: Oral microbiota is believed to play important roles in systemic diseases, including cancer. Methods: We collected oral samples (tongue, buccal, supragingival, and saliva) and pancreatic tissue or intestinal samples from 52 subjects, and characterized 16S rRNA genes using high-throughput DNA sequencing.

Results: Bray–Curtis plot showed clear separations between bacterial communities in the oral cavity and those in intestinal and pancreatic tissue samples. PERMANOVA tests indicated that bacterial communities from buccal samples were similar to supragingival and saliva samples, and pancreatic duct samples were similar to pancreatic tumor samples, but all other samples were significantly different from each …

Investigating Microbial And Host Factors That Modulate Severity Of Clostridioides Difficile Associated Disease, Armando Lerma

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Clostridioides difficile is recognized as one of the most important pathogens in hospital and community healthcare settings. The clinical outcome of infection of toxigenic C. difficile infection (CDI) ranges from asymptomatic colonization to fulminant pseudomembranous colitis and death. In recent studies, it has been suggested that a high proportion of nosocomial CDI cases are transmitted from asymptomatic carriers which might be acting as infection reservoirs. Understanding what causes the different responses to infection could lead to the development of novel prevention and treatment strategies. Although several explanations have been proposed to explain variations in susceptibility, understanding of the exact mechanisms …

Smrt Sequencing Of Paramecium Bursaria Chlorella Virus-1 Reveals Diverse Methylation Stability In Adenines Targeted By Restriction Modification Systems, Samantha R. Coy, Eric R. Gann, Spiridon E. Papoulis, Michael E. Holder, Nadim J. Ajami, Joseph F. Petrosino, Erik R. Zinser, James L. Van Etten, Steven W. Wilhelm

James Van Etten Publications

Chloroviruses (family Phycodnaviridae) infect eukaryotic, freshwater, unicellular green algae. A unique feature of these viruses is an abundance of DNA methyltransferases, with isolates dedicating up to 4.5% of their protein coding potential to these genes. This diversity highlights just one of the long-standing values of the chlorovirus model system; where group-wide epigenomic characterization might begin to elucidate the function(s) of DNA methylation in large dsDNA viruses. We characterized DNA modifications in the prototype chlorovirus, PBCV-1, using single-molecule real time (SMRT) sequencing (aka PacBio). Results were compared to total available sites predicted in silico based on DNA sequence alone. SMRT-software detected …

Dgts Production As A Phosphate Starvation Response In The Human Fungal Pathogen Candida Albicans, Caleb J. Wehling

School of Biological Sciences: Dissertations, Theses, and Student Research

Betaine lipids are a class of membrane lipids with betaine head groups. Three betaine lipids are known: diacylglyceryltrimethylhomoserine (DGTS), diacylglycerylhydroxymethylalanine (DGTA), and diacylglycerylcarboxymethylcholine (DGCC). Betaine lipids are most common in algae, although DGTS, the most common betaine lipid, is also found in many bacteria and fungi. Organisms which produce betaine lipids (especially DGTS) often don’t produce phosphatidylcholine (PtdCho), and DGTS structure resembles PtdCho structure without any phosphorous, leading to the hypothesis that betaine lipids may substitute for phospholipids in some organisms. This has been confirmed by discoveries that some organisms are capable of switching their membrane composition from PtdCho to …

On The Inadequacy Of Species Distribution Models For Modelling The Spread Of Sars-Cov-2: Response To Araújo And Naimi, Joseph D. Chipperfield, Blas M. Benito, Robert B. O'Hara, Richard J. Telford, Colin J. Carlson

United States Public Health Resources

The ongoing pandemic of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing significant damage to public health and economic livelihoods, and is putting significant strains on healthcare services globally. This unfolding emergency has prompted the preparation and dissemination of the article “Spread of SARS-CoV-2 Coronavirus likely to be constrained by climate” by Araújo and Naimi (2020). The authors present the results of an ensemble forecast made from a suite of species distribution models (SDMs), where they attempt to predict the suitability of the climate for the spread of SARS-CoV-2 over the coming months. They argue that climate is …

Mucosa-Associated Microbiota In Barrett’S Esophagus, Dysplasia, And Esophageal Adenocarcinoma Differ Similarly Compared With Healthy Controls, Shajan Peter, Amanda Pendergraft,, William Vanderpol, Mel Wilcox, Kondal R. Kyanam Kabir Baig, Casey Morrow, Jacques Izard, Peter J. Mannon

Department of Food Science and Technology: Faculty Publications

Introduction: Alterations in the composition of the human gut microbiome and its metabolites have been linked to gut epithelial neoplasia. We hypothesized that differences in mucosa-adherent Barrett’s microbiota could link to risk factors, providing risk of progression to neoplasia.

Methods: Paired biopsies from both diseased and nonaffected esophagus (as well as gastric cardia and gastric juice for comparison) from patients with intestinal metaplasia (n = 10), low grade dysplasia (n = 10), high grade dysplasia (n = 10), esophageal adenocarcinoma (n = 12), and controls (n = 10) were processed for mucosa-associated bacteria …

Environmental Sampling Techniques For Herd-Level Surveillance Of Bovine Viral Diarrhea Virus, Jaden Carlson

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Control of Bovine Viral Diarrhea Virus (BVDV) relies on resource-intensive individual animal sampling to detect and remove persistently infected (PI) cattle. Herd-level surveillance tools would be useful for herds with unknown BVDV status and for monitoring herds with BVDV-free status. The overall objective of this thesis is to explore the viability of BVDV surveillance at a herd-level using samples collected without handling individual animals. The first objective was to determine the feasibility of using stable flies as a sampling tool to detect BVDV. The second objective was to determine the feasibility of using drinking water to detect BVDV. To accomplish …

Regulation Of Vaccinia Virus Replication: A Story Of Viral Mimicry And A Novel Antagonistic Relationship Between Vaccinia Kinase And Pseudokinase, Annabel T. Olson

School of Biological Sciences: Dissertations, Theses, and Student Research

Poxviruses employ sophisticated signaling pathways that thwart cellular defense mechanisms and simultaneously ensure viral factors are modulated properly. Yet, our understanding of these complex signaling networks are incomplete. For example, the vaccinia B1 kinase plays a vital role in inactivating the cellular antiviral factor BAF, and is suggested to orchestrate other pathways. B1 is highly conserved among poxviruses and exhibits a remarkable degree of similarity to VRKs, a family of cellular kinases, suggesting that the viral enzyme has evolved to mimic VRK activity. Indeed, B1 and VRKs have been demonstrated to target a shared substrate, the DNA binding protein BAF, …

The N-Glycan Structures Of The Antigenic Variants Of Chlorovirus Pbcv-1 Major Capsid Protein Help To Identify The Virus-Encoded Glycosyltransferases, Immacolata Speciale, Garry A. Duncan, Luca Unione, Irina Agarkova, Domenico Garozzo, Jesus Jimenez-Barbero, Sicheng Lin, Todd L. Lowary, Antonio Molinaro, Eric Noel, Maria Elena Laugieri, Michela Tonetti, James L. Van Etten, Cristina De Castro

James Van Etten Publications

The chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1) is a large dsDNA virus that infects the microalga Chlorella variabilis NC64A. Unlike most other viruses, PBCV-1 encodes most, if not all, of the machinery required to glycosylate its major capsid protein (MCP). The structures of the four N-linked glycans from the PBCV-1 MCP consist of nonasaccharides, and similar glycans are not found elsewhere in the three domains of life. Here, we identified the roles of three virus-encoded glycosyltransferases (GTs) that have four distinct GT activities in glycan synthesis. Two of the three GTs were previously annotated as GTs but the third …