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The Effect Of Intracellular Zinc Levels In Escherichia Coli On Metallo-Β-Lactamase Activity, Jill Thompson

Graduate School of Biomedical Sciences Theses and Dissertations

Antibiotic resistance is a consequence of evolution via natural selection and poses a serious threat to the world's population. Escherichia coli, and other bacterial species, have acquired genes encoding Metallo-β-Lactamases (MBLs). MBLs are zinc-dependent enzymes that degrade most β-lactam antibiotics, and have emerged as important antibacterial resistance determinants in multidrug resistant pathogens. There are several different families of MBLs, and the major clinically relevant ones are Verona Integrated-encoded Metallo-β-Lactamases (VIMs), Imipenemases (IMPs), and New Delhi Metallo-β-Lactamases (NDMs). These enzymes confer high level resistance to penicillins, cephalosporins, and carbapenems, and are not inhibited by FDA-approved β-lactamase inhibitors. Variants of NDM have …

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 …

The Cxcr2-Dependent Role Of Cancer-Associated Fibroblasts In Pancreatic Ductal Adenocarcinoma, Mohammad Awaji

Theses & Dissertations

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer, the fourth leading cause of cancer-related deaths in the USA with over 40,000 deaths per year. Unlike other major cancer types, the progress in dealing with PDAC is plodding, attributed mainly to the asymptomatic nature of the disease, the late diagnosis and the ineffectiveness of current therapies. A better understanding of the biology of the disease could permit the discovery of novel diagnostic and therapeutic tools. With that in mind, we present this dissertation that investigates the tumor-stromal interaction underlined by genetic alterations and inflammation. PDAC develop as …

Developing Targeted Therapy Against Pancreatic Cancer, Garima Kaushik

Theses & Dissertations

Not available.

The Signaling Pathways Of Metallothionein-Mediated Chemotaxis In Breast Cancer, Jennifer Messina

University Scholar Projects

Metallothionein (MT) is a small, thiol rich protein released into the extracellular environment in response to stress. Elevated expression of MT has been linked to many inflammatory diseases including inflammatory bowel diseases, diabetes, and cancer. In breast cancer, high expression of MT has been associated with poor patient prognosis. Previous studies have shown that MT acts as a chemoattractant in lymphocytes, and that UC1MT, a monoclonal anti-MT antibody, can block this chemotactic response. In addition, it has been shown that both Cholera toxin and Pertussis toxin, which are known antagonists of G-protein coupled receptors, can inhibit MT-mediated chemotaxis. Here, I …

Defects In Fetal Mouth Movement And Pharyngeal Patterning Underlie Cleft Palate Caused By Retinoid Deficiency., Regina Friedl

Electronic Theses and Dissertations

Cleft palate is a common birth defect. Etiologic mechanisms of palate cleft include defects in palate morphogenesis, mandibular growth, or spontaneous fetal mouth movement. Cleft palate linked to deficient fetal mouth movement has been demonstrated directly only in a single experimental model of loss of neurotransmission. Here, using retinoid deficient mouse embryos, we demonstrate directly for the first time that deficient fetal mouth movement and cleft palate occurs as a result of mis-patterned development of pharyngeal peripheral nerves and cartilages. Retinoid deficient embryos were generated by inactivation of retinol dehydrogenase 10 (Rdh10), which is critical for production of …

The Signaling Pathways Of Metallothionein-Mediated Chemotaxis In Breast Cancer, Jennifer Messina

Honors Scholar Theses

Metallothionein (MT) is a small, thiol rich protein released into the extracellular environment in response to stress. Elevated expression of MT has been linked to many inflammatory diseases including inflammatory bowel diseases, diabetes, and cancer. In breast cancer, high expression of MT has been associated with poor patient prognosis. Previous studies have shown that MT acts as a chemoattractant in lymphocytes, and that UC1MT, a monoclonal anti-MT antibody, can block this chemotactic response. In addition, it has been shown that both Cholera toxin and Pertussis toxin, which are known antagonists of G-protein coupled receptors, can inhibit MT-mediated chemotaxis. Here, I …

Spatial Reorganization Of Histone-Like Nucleoid Structuring Proteins Caused By Silver Nanoparticles, Meaad Alqahtany

Graduate Theses and Dissertations

Silver nanoparticles (AgNPs) and ions (Ag+) can be the new generation of antibiotics due to their antimicrobial effects against bacteria and other microbes. Many studies have shown that AgNPs and suppress the growth of bacteria and damage the cell walls of the microbes; therefore, treating bacterial cells with AgNPs may be a promising method to terminate multi-resistant bacteria. In this work, the effect of AgNPs with two different surface coatings on the spatial reorganization of histone-like nucleoid structuring (H-NS) proteins in Escherichia coli bacteria was investigated using quantitative super-resolution fluorescence microscopy to understand the toxicity and antimicrobial mechanism of AgNPs. …

Attenuated Responses To Inflammatory Cytokines In Mouse Embryonic Stem Cells: Biological Implications And The Molecular Basis, Bohan Chen

Master's Theses

Embryonic stem cells (ESCs) have attracted intense interest due to their great potential for regenerative medicine. However, their immune property is an overlooked but a significant issue that needs to be thoroughly investigated not only to resolve the concern for therapeutic applications but also for further understanding the early stage of organismal development. Recent studies demonstrated that ESCs are deficient in innate immune responses to viral/bacterial infections and inflammatory cytokines. Inflammatory conditions generally inhibit cell proliferation, which could be detrimental to ESCs, since cell proliferation is their dedicated task during early embryogenesis. Thus, I hypothesize that the attenuated innate immunity …

Il-6/Jak1 Drives Pd-L1 Phosphorylation And Glycosylation To Promote Cancer Immune Evasion, Li-Chuan Chan

Dissertations and Theses (Open Access)

Glycosylation of immune receptors and ligands, such as T-cell receptor (TCR), major histocompatibility complex (MHC), and co-inhibitory molecules, regulates immune signaling activation, antigen presentation, and immune surveillance. Recent studies revealed that the glycan structures of co-inhibitory molecules are required for receptor-ligand interaction, a critical feature for activating cancer immune evasion. However, it is unclear how oncogenic signaling initiates glycosylation of co-inhibitory molecules to induce immunosuppression. Here we show interleukin (IL)-6-activated Janus kinase 1 (JAK1) phosphorylates programmed death-ligand 1 (PD-L1)-Tyr112, leading to the recruitment of endoplasmic reticulum (ER)-associated N-glycosyltransferase, STT3A, which catalyzes the glycosylation of PD-L1, contributing to its stability. A …

Cross-Presentation Is A Source Of Tumor Antigens For Multiple Myeloma Immunotherapy, Alexander A. Perakis

Dissertations and Theses (Open Access)

Cross-presentation is an essential bridge between the innate and adaptive arms of the immune system where antigen presenting cells (APCs) prime cytotoxic T cell responses. We have recently identified cross-presentation as a mechanism by which solid tumors present exogenous antigens. We therefore hypothesized that multiple myeloma would be capable of cross-presentation as these cells are derived from B cells, known APCs. We explored the capacity of multiple myeloma to cross-present PR1, a human leukocyte antigen (HLA)-A2 nonameric peptide that is derived from neutrophil elastase (NE) and proteinase 3 (P3), and the ability to treat multiple myeloma using PR1-targeting immunotherapies. Here …

Immunogenicity Of Tumor Initiating Stem Cells: Potential Applications In Novel Anticancer Therapy, Durga Khandekar, Suneetha Amara, Venkataswarup Tiriveedhi

Biology Faculty Research

Tumor initiating stem cells (TISCs) are a subset of tumor cells, which are implicated in cancer relapse and resistance to chemotherapy. The metabolic programs that drive TISC functions are exquisitely unique and finely-tuned by various oncogene-driven transcription factors to facilitate pro-cancerous adaptive challenges. While this change in TISC metabolic machinery allows for the identification of associated molecular targets with diagnostic and prognostic value, these molecules also have a potential immunological application. Recent studies have shown that these TISC-associated molecules have strong antigenic properties enabling naïve CD8+T lymphocytes to differentiate into cytotoxic effector phenotype with anticancer potential. In spite of the …

Body Mass Index In Multiple Sclerosis Modulates Ceramide-Induced Dna Methylation And Disease Course, Kamilah Castro, Achilles Ntranos, Mario Amatruda, Maria Petracca, Peter Kosa, Emily Y. Chen, Johannes Morstein, Dirk Trauner, Corey T. Watson, Michael A. Kiebish, Bibiana Bielekova, Matilde Inglese, Ilana Katz Sand, Patricia Casaccia

Advanced Science Research Center

Background: Multiple Sclerosis (MS) results from genetic predisposition and environmental variables, including elevated Body Mass Index (BMI) in early life. This study addresses the effect of BMI on the epigenome of monocytes and disease course in MS.

Methods: Fifty-four therapy-naive Relapsing Remitting (RR) MS patients with high and normal BMI received clinical and MRI evaluation. Blood samples were immunophenotyped, and processed for unbiased plasma lipidomic profiling and genome-wide DNA methylation analysis of circulating monocytes. The main findings at baseline were validated in an independent cohort of 91 therapy-naïve RRMS patients. Disease course was evaluated by a two-year longitudinal follow up …

Enhancing Immunotherapeutic Interventions For Treatment Of Chronic Lymphocytic Leukemia, Kamira K. Maharaj

USF Tampa Graduate Theses and Dissertations

Chronic lymphocytic leukemia (CLL) is the most common leukemia in developed countries. It is characterized by the accumulation of CD5+ B lymphocytes in the peripheral blood, bone marrow, and lymphoid tissues of affected patients. Patients experience lymphadenopathy, fatigue, and are severely immunocompromised. Management of disease and symptoms is possible with chemo-immunotherapy for higher risk patients; however, CLL remains incurable unless bone marrow transplant is performed. Identification of novel targets and optimization of current therapeutics is therefore still necessary. The new targeted therapies are at the forefront of development for CLL treatment, but it remains challenging to maximize their efficacies while …

The One Health Approach To Toxoplasmosis: Epidemiology, Control, And Prevention Strategies, A. Alonso Aguirre, Travis Longcore, Michelle Barbieri, Haydee Dabritz, Dolores Hill, Patrice N. Klein, Christopher Lepczyk, Emily L. Lilly, Rima Mcleod, Judith Milcarsky, Caroline E. Murphy, Chunlei Su, Elizabeth Vanwormer, Robert Yolken, Grant C. Sizemore

School of Veterinary and Biomedical Sciences: Faculty Publications

One Health is a collaborative, interdisciplinary effort that seeks optimal health for people, animals, plants, and the environment. Toxoplasmosis, caused by Toxoplasma gondii, is an intracellular protozoan infection distributed worldwide, with a heteroxenous life cycle that practically affects all homeotherms and in which felines act as definitive reservoirs. Herein, we review the natural history of T. gondii, its transmission and impacts in humans, domestic animals, wildlife both terrestrial and aquatic, and ecosystems. The epidemiology, prevention, and control strategies are reviewed, with the objective of facilitating awareness of this disease and promoting transdisciplinary collaborations, integrative research, and capacity building among universities, …

Transposon Mutagenesis In Mycobacterium Avium Subspecies Paratuberculosis, John P. Bannantine, Denise K. Zinniel, Raul G. Barletta

School of Veterinary and Biomedical Sciences: Faculty Publications

While transposon mutagenesis has been developed for Mycobacterium avium subspecies paratuberculosis (Map), relatively few laboratories have adopted this important genetic tool to examine gene function and essentiality. Here we describe the construction of a Map transposon library using the Himar1 mariner transposon, but concepts can also be applied to the Tn5367 transposon, which has also been used by our group. Delivery of the transposon is by a temperature-sensitive phagemid, ϕMycoMarT7, and plating transductants requires patience and specialized media due to length of incubation required to observe colonies. Several transposon mutants obtained from these libraries have been tested in vaccine and …

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 …

Environmental Transmission Of Toxoplasma Gondii: Oocysts In Water, Soil And Food, Karen Shapiro, Lillian Bahia-Oliveira, Brent Dixon, Aurélien Dumètre, Luz A. De Wit, Elizabeth Vanwormer, Isabelle Villena

School of Veterinary and Biomedical Sciences: Faculty Publications

Toxoplasma gondii is a zoonotic protozoan parasite that can cause morbidity and mortality in humans, domestic animals, and terrestrial and aquatic wildlife. The environmentally robust oocyst stage of T. gondii is fundamentally critical to the parasite's success, both in terms of its worldwide distribution as well as the extensive range of infected intermediate hosts. Despite the limited definitive host species (domestic and wild felids), infections have been reported on every continent, and in terrestrial as well as aquatic environments. The remarkable resistance of the oocyst wall enables dissemination of T. gondii through watersheds and ecosystems, and long-term persistence in diverse …

Kinetic Analysis And Epitope Mapping Of Monoclonal Antibodies To Salmonella Typhimurium Flagellin Using A Surface Plasmon Resonance Biosensor, Devendra Bhandari, Fur-Chi Chen, Shreya Hamal, Roger C. Bridgman

Human Sciences Faculty Research

Salmonella Typhimurium is one of the leading causes of foodborne diseases worldwide. Biosensors and immunoassays utilizing monoclonal antibodies are widely used for the detection and subtyping of S. Typhimurium. However, due to insufficient information on the nature of binding with S. Typhimurium flagellin, the selection of appropriate antibodies for assay development is a cumbersome task. Hence, we aimed to compare the binding kinetics of a panel of monoclonal antibodies and their relative binding sites to flagellin antigen using a surface plasmon resonance biosensor. Initially, the flagellin was captured on the sensor surface through an immobilized anti-flagellin antibody. The interactions of …

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 …

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, …

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 …

Plasmodium Para-Aminobenzoate Synthesis And Salvage Resolve Avoidance Of Folate Competition And Adaptation To Host Diet, Joachim Michael Matz, Mutsumi Watanabe, Mofolusho Falade, Takayuki Tohge, Rainer Hoefgen, Kai Matuschewski

Pharmaceutical Sciences Faculty Publications

Folate metabolism is essential for DNA synthesis and a validated drug target in fast-growing cell populations, including tumors and malaria parasites. Genome data suggest that Plasmodium has retained its capacity to generate folates de novo. However, the metabolic plasticity of folate uptake and biosynthesis by the malaria parasite remains unresolved. Here, we demonstrate that Plasmodium uses an aminodeoxychorismate synthase and an aminodeoxychorismate lyase to promote the biogenesis of the central folate precursor para-aminobenzoate (pABA) in the cytoplasm. We show that the parasite depends on de novo folate synthesis only when dietary intake of pABA by …

Systemic Inhibition Of Tissue-Nonspecific Alkaline Phosphatase Alters The Brain-Immune Axis In Experimental Sepsis, Allison L. Brichacek, Stanely A. Benkovic, Sreeparna Chakraborty, Divine C. Nwafor, Wei Wang, Sujung Jun, Duaa Dakhlallah, Werner Geldenhuys, Anthony B. Pinkerton, José Luis Millán, Candice M. Brown

Faculty & Staff Scholarship

Tissue-nonspecific alkaline phosphatase (TNAP) is a ubiquitous enzyme present in many cells and tissues, including the central nervous system. Yet its functions at the brain-immune axis remain unclear. The goal of this study was to use a novel small molecular inhibitor of TNAP, SBI-425, to interrogate the function of TNAP in neuroimmune disorders. Following intraperitoneal (IP) administration of SBI-425, mass spectrometry analysis revealed that the SBI-425 does not cross the blood-brain barrier (BBB) in healthy mice. To elucidate the role of TNAP at the brain-immune axis, mice were subjected to experimental sepsis and received either vehicle or SBI-425 (25 mg/kg, …

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 …

New Insights Into Mycofactocin Biosynthesis, Structure And Function, Richard Selorm Ayikpoe

Electronic Theses and Dissertations

Mycofactocin is a putative ribosomally synthesized and post-translationally modified peptide (RiPP)-derived redox cofactor. Its biosynthesis is accomplished through the dedicated actions of the products of six conserved genes, mftABCDEF. The mycofactocin pathway is one of the most widely distributed RiPP systems in bacteria however, this distribution is heavily skewed towards the Mycobacteria genus including human pathogenic variants such as M. tuberculosis and M. ulcerans. Gene expression studies have demonstrated the essentiality of the pathway in the ability of M. tuberculosis to utilize the host's cholesterol as sole carbon source during latency. However, the biosynthesis, structure and physiological function …

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 …

Novel Amphiphilic Cyclobutene And Cyclobutane Cis-C18 Fatty Acid Derivatives Inhibit Mycobacterium Avium Subsp. Paratuberculosis Growth, Denise K. Zinniel, Wantanee Sittiwong, Darrell D. Marshall, Govardhan Rathnaiah, Isin T. Sakallioglu, Robert Powers, Patrick H. Dussault, Raul G. Barletta

School of Veterinary and Biomedical Sciences: Faculty Publications

Mycobacterium avium subspecies paratuberculosis (Map) is the etiologic agent of Johne’s disease in ruminants and has been associated with Crohn’s disease in humans. An effective control of Map by either vaccines or chemoprophylaxis is a paramount need for veterinary and possibly human medicine. Given the importance of fatty acids in the biosynthesis of mycolic acids and the mycobacterial cell wall, we tested novel amphiphilic C₁₀ and C₁₈ cyclobutene and cyclobutane fatty acid derivatives for Map inhibition. Microdilution minimal inhibitory concentrations (MIC) with 5 or 7 week endpoints were measured in Middlebrook 7H9 base broth media. We compared the …

Investigation Of Congestive Heart Failure In Beef Cattle In A Feedyard At A Moderate Altitude In Western Nebraska, Rodney A. Moxley, David R. Smith, Dale M. Grotelueschen, Tom Edwards, David Steffen

School of Veterinary and Biomedical Sciences: Faculty Publications

Right-sided congestive heart failure (brisket disease) commonly occurs in cattle raised at elevations >2,500– 3,500 m. We investigated clinical cases resembling brisket disease at a western Nebraska feedyard at a moderate altitude (1,369 m). Over a 15-mo period (2009–2010), we examined 17 cases (16 steers and 1 heifer), all purebred Angus. All animals had clinical right-sided heart failure: brisket and ventral abdominal edema, and severe chronic passive congestion of the liver. Gross examination confirmed right ventricular hypertrophy (left ventricle plus septum: right ventricle weight ratio mean: 1.33 vs. 2.8–4.0 reference interval). Microscopically, all 17 cases had interstitial fibrosis (mean score: …

Ehdv-2 Infection Prevalence Varies In Culicoides Sonorensis After Feeding On Infected White-Tailed Deer Over The Course Of Viremia, Sandra Y. Mendiola, Mary K. Mills, Elin Maki, Barbara S. Drolet, William C. Wilson, Roy D. Berghaus, David E. Stallknecht, Jonathan Breitenbach, D. Scott Mcvey, Mark G. Ruder

School of Veterinary and Biomedical Sciences: Faculty Publications

Epizootic hemorrhagic disease viruses (EHDVs) are arboviral pathogens of white-tailed deer and other wild and domestic ruminants in North America. Transmitted by various species of Culicoides, EHDVs circulate wherever competent vectors and susceptible ruminant host populations co-exist. The impact of variation in the level and duration of EHDV viremia in white-tailed deer (Odocoileus virginianus) on Culicoides infection prevalence is not well characterized. Here we examined how infection prevalence in a confirmed North American vector of EHDV-2 (Culicoides sonorensis) varies in response to fluctuations in deer viremia. To accomplish this, five white-tailed deer were experimentally infected with EHDV-2 and colonized C. …