Elucidation Of The Post-Transcriptional Regulation And Role In Iron Homeostasis Of The Outer Membrane Vesicle Protein Ynce In Salmonella, Mira J. Schmidt

Honors Undergraduate Theses

Iron is an essential element for most bacteria as it is a crucial cofactor for enzymes involved in fundamental reactions such as DNA synthesis. Despite being the fourth most abundant element on Earth, bacteria face challenges acquiring iron under aerobic conditions due to the poor solubility of its oxidized form (Fe³⁺). To overcome this, bacteria have developed various strategies of iron acquisition, such as the production of siderophores. Siderophores are small molecules that scavenge free Fe³⁺ in iron-deprived environments. Iron acquisition is tightly regulated due to its capability of promoting hydrogen peroxide formation via the Fenton reaction. In Salmonella Typhimurium, …

Schistosoma Mansoni Infection Causes Consistent Changes To The Fecal Bacterial Microbiota Of Mice Across And Within Sites, Mariam A. Mhanna, David T. Gauthier, Lisa M. Shollenberger

Biological Sciences Faculty Publications

Eggs of Schistosoma mansoni are produced by adult female worms in mesenteries of infected hosts. Eggs can cross the intestinal barrier and form granulomas in the tissue or breach and exit the host through fecal excretion. These interactions may affect the host microbiome assemblages. Given the potential for schistosomal alteration of host gut microbiome and subsequent effects on the fecal bacterial composition, it is important to conduct controlled microbiome studies on model animals. While pursuing these studies, it is important to take into account the different conditions in which microbiome studies are conducted and their consequent impacts on variability and …

Exploring The Role Of Host Immune Responses And Bacterial Sensory Pathways In The Development Of Treponema Denticola-Mediated Periodontal Disease, Annie N. Hinson

Theses and Dissertations

Periodontitis is a chronic inflammatory disease driven by dysbiotic microbial communities and maladaptive host responses. Treponema denticola, a spirochete pathobiont, is strongly associated with disease severity. However, the molecular mechanisms underlying its interaction with host tissues and regulation of virulence remain incompletely understood. This work examines both the epithelial immune responses and bacterial transduction systems that shape T. denticola pathogenesis. Transcriptomic analysis of gingival keratinocytes revealed IL-36γ as the most highly induced cytokine following infection with T. denticola. Functional studies demonstrated that IL-36γ induction occurs in a dose- and time-dependent manner through TLR2/6 signaling, requiring the NF-κB, PI3K/Akt, and …

Functional Analysis Of Ligand Binding Domain 2 Of Outer Surface Protein C Of Borreliella Burgdorferi, Gavin Z. Chambers

Theses and Dissertations

Lyme disease, caused by the spirochete Borreliella burgdorferi, is the most common vector-borne infection in North America. A critical determinant of early mammalian infection is outer surface protein C (OspC), a highly variable lipoprotein that is indispensable for spirochete survival but whose precise function remains unresolved. OspC has been proposed to mediate diverse roles, including complement evasion, adhesion, tissue dissemination, and antiphagocytic activity, supporting the view that it is a multifunctional virulence factor. Structural studies have identified two putative ligand-binding domains (LBD1 and LBD2), with LBD2 forming a solvent-exposed crown at the membrane-distal end of the OspC dimer.

To …

Antibody-Induced Multicellular Behaviors Of Salmonella Typhimurium, Samantha K. Lindberg

Electronic Theses & Dissertations (2024 - present)

Salmonella enterica is a globally distributed bacterial pathogen that is commonly acquired through consumption of contaminated food and water. The enterica subspecies includes over 1500 unique subvariants, or serovars, that are classified by antigen presentation. Due to its global environmental prevalence, broad host range, and increasing pathogenicity, serovar Typhimurium is of particular concern for human and animal health, as well as food safety. Once in the gastrointestinal tract, Salmonella Typhimurium (STm) exploits host immune mechanisms, implements an arsenal of virulence factors, and outcompetes the microbiota to invade the intestinal epithelium. While STm infections are generally self-limiting and relatively mild, emerging …

Engineering Extracellular Vesicles (Evs) To Combat Infection And Inflammation In Cystic Fibrosis, Sharanya Sarkar

Dartmouth College Ph.D Dissertations

Cystic Fibrosis (CF) is a multisystemic genetic disorder caused by mutations in the CFTR gene, resulting in chronic pulmonary infections, hyperinflammation, and progressive lung damage. Among the pathogens that colonize CF lungs, Pseudomonas aeruginosa (P. aeruginosa) is predominant, infecting over 50% of adults with CF and developing antibiotic resistance over time. Current modulator therapies fail to address persistent bacterial infections, chronic inflammation, or irreversible lung damage, underscoring the need for novel therapeutic strategies. In our previous in vitro studies, we demonstrated that extracellular vesicles (EVs) secreted by primary Human Bronchial Epithelial Cells (HBECs) inhibit P. aeruginosa growth by reducing the …

Interactions Of The Sars-Cov-2 Viral Genome 3’-Untranslated Region With Viral And Host Rnas, Caleb Frye, Mihaela Rita Mihailescu

Electronic Theses and Dissertations

This dissertation focuses on the characterization of RNA-RNA interactions within the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome and with host microRNAs. As the causative agent of coronavirus disease 2019 (COVID-19), SARS-CoV-2 has evolved rapidly since its appearance. This has warranted prompt characterization of the virus particularly of its single stranded RNA (ssRNA) genome. By using a combination of bioinformatics, biophysics, and/or biological assays, we analyzed the SARS-CoV-2 viral genomic RNA and uncovered interactions of genomic RNA with host RNAs, highlighting an underutilized method of targeting RNA viruses. We showed here that the conserved elements in the viral genomic …

Differential Responses Of Human Neutrophils To Legionella Species., Hannah E. Hanford

Electronic Theses and Dissertations

Legionella species are Gram-negative facultative intracellular bacterial pathogens commonly found in freshwater or soil environments where they survive and replicate within their natural protozoan hosts. Humans serve as an accidental host for Legionella species after inhalation of contaminated aerosolized water droplets or soil particles enabling the bacteria to enter the lungs, infect alveolar macrophages, and result in severe pneumonia. Evasion of degradation and proliferation within alveolar macrophages by Legionella species and manifestation of “Legionnaires’ disease” is dependent on the Dot/Icm type IV secretion system (T4SS). The T4SS apparatus is a needle-like channel for translocation of over ~350 effector proteins, depending …

Lack Of Inflammatory Response In Mouse Embryonic Cells To Listeria Infection, Damilola Oyebode

Master's Theses

Approximately 1 in 5 pregnancies in the United States results in miscarriage, with a significant percentage of these losses attributed to failed implantation due to immunological challenges encountered by the early embryo. Recent research has shown that key cell types within mouse blastocysts, including embryonic stem cells (ESCs) and trophoblast stem cells (TSCs), exhibit remarkable resilience against the cytotoxic effects associated with viral infections and embryotoxic cytokines, such as TNFα and IFNγ, both of which are known to hinder blastocyst development. However, the immune properties of the preimplantation stage embryo, specifically the blastocyst, remain poorly understood. Using mouse cell model, …

Implementing The Methodology To Generate Diagnostic And Therapeutic Antibodies, Andrea Mariana Carlin

Open Access Theses & Dissertations

This research aimed to establish the methodology for developing monoclonal antibodies at The University of Texas at El Paso. Monoclonal antibodies are indispensable across multiple fields, including diagnostics, therapeutics, and biotechnology, yet there is a shortage of commercially available antibodies targeting specific proteins or possessing specialized characteristics. To address this gap, three models were selected: a peptide derived from the intracellular protein Schlafen 8 and two cell surface protein receptors: mouse vascular endothelial growth factor receptor 2 (VEGFR2) and human melanocortin receptor 4 (MC4R). These proteins present unique challenges in antibody generation, including issues of accessibility, expression, and specificity.

Throughout …

Enhancement Of Zika Virus Infection By West Nile And Dengue Virus Antibody Positive Cord-Blood Samples From Mothers In El Paso-Texas, Jeanette Orbegozo

Open Access Theses & Dissertations

The recent Zika virus (ZIKV) outbreak and its association with microcephaly cases and other neurological syndromes are important public health concerns. A phenomenon known as antibody-dependent enhancement (ADE) involves preexisting flavivirus antibodies to a specific flavivirus that enhances the severity of a second infection with a different flavivirus. Since ZIKV is related to flaviviruses like West Nile virus (WNV) and dengue virus (DENV), prior exposure to these viruses could elicit cross-reactive antibodies that may enhance a subsequent ZIKV infection. Therefore, this study aimed to determine if WNV and DENV antibodies from cord blood enhanced ZIKV infection in vitro. Initially, a …

Natural Panola Mountain Ehrlichia Infections In Cattle In A Longitudinal Study Of Angus Beef Calves, Cierra Briggs, Drew Casey, Anna Grace Deakins, Jeremy G. Powell, Kelly Loftin, Emily G. Mcdermott

Entomology and Plant Pathology Faculty Publications and Presentations

Panola Mountain Ehrlichia (PME) is an emerging zoonotic pathogen, transmitted by Amblyomma americanum ticks in the southeastern United States. It is closely related to Ehrlichia ruminantium, the causative agent of heartwater disease. Heartwater disease is an often-fatal illness of ruminant livestock present in Africa and the Caribbean. The taxonomic relationship between PME and E. ruminantium has raised concerns about the pathogenicity of PME in livestock. To determine whether cattle could be naturally infected with PME in an endemic area, we conducted a one-year longitudinal study of Angus-breed beef calves in Fayetteville, Arkansas. One hundred seventy-seven calves born between September …

The Dengue Vaccine Initiative: A Bibliometric Analysis Of Research Publications, Festus Mulakoli, Abednego Ongeso, Horatius Musembi

School of Nursing & Midwifery, East Africa

Dengue fever has become a significant public health problem in tropical and subtropical regions and affects millions of people annually. Approximately 390 million people worldwide are estimated to be infected with dengue every year, of which 96 million develop dengue fever. Recently, there has been a noticeable increase in dengue cases, primarily in areas with tropical and subtropical climates. Vaccines have been developed to prevent or reduce the severity of the disease. This study reviews the number of publications on dengue vaccines and related topics worldwide. We aimed to evaluate the research output and create a narrative on global vaccine …

Molecular Detection Of Mycoplasma Spp. And Its Associated Risk Factors In Domestic Cats In The City Of Ibagué, Tolima, Karen D. Osorio Muñoz Dr., Iang S. Rondon Barragan Prof.

The Thai Journal of Veterinary Medicine

Feline hemoplasmosis is a disease with worldwide distribution, mainly in tropical countries, where its transmission is favored by the presence of vectors such as fleas and ticks. In Colombia, the diagnosis of the disease in small animals has been limited to the identification of the pathogen in blood smears, which have low sensitivity and specificity, demanding methods of higher diagnostic value, such as those based on molecular techniques. The objective of the present study was to investigate the prevalence of Mycoplasma spp. in felines from the city of Ibagué using the PCR and the associated risk factors. Briefly, blood samples …

The Roles Of Cd4+ T Cell Help, Sex, And Dose In The Induction Of Protective Cd8+ T Cells Against A Lethal Poxvirus By Mrna-Lnp Vaccines, Samita Kafle, Brian Montoya, Lingjuan Tang, Ying Tam, Hiromi Muramatsu, Norbert Pardi, Luis Sigal

Department of Microbiology and Immunology Faculty Papers

The role of CD4⁺ T cells in the induction of protective CD8⁺ T cells by mRNA lipid nanoparticle (LNP) vaccines is unknown. We used B6 or Tlr9^−/− mice depleted or not of CD4⁺ T cells and LNP vaccines loaded with mRNAs encoding the ectromelia virus (ECTV) MHC class I H-2 K^b-restricted immunodominant CD8⁺ T cell epitope TSYKFESV (TSYKFESV mRNA-LNPs) or the ECTV EVM158 protein, which contains TSYKFESV (EVM-158 mRNA-LNPs). Following prime and boost with 10 μg of either vaccine, K^b-TSYKFESV-specific CD8⁺ T cells fully protected male and female mice from …

Cognition And Inflammation In Youth With Perinatal Hiv, Megan Niehaus, Julie Mannarino, Jacob Bolzenius, Tori Frerichs, Robert Paul

Undergraduate Research Symposium

Background: Perinatally acquired HIV (PHIV) remains a major global health challenge. Approximately 90% of the global population of PHIV reside in low- or middle-income countries (LMICs) where access to antiretroviral therapy (ART) remains incomplete, particularly for PHIV. With PHIV, the brain is exposed to the virus during critical periods of brain development without the immunological benefits from ART. Unlike adults with horizontally acquired HIV whose nadir CD4+ Tcell count is a strong correlate of cognitive difficulties that persist after sustained use of ART, cognitive symptoms among PHIV youth are independent of traditional HIV disease metrics. Prior studies indicate that PHIV …

Inactivated Rabies-Based Lassa Fever Virus Vaccine Candidate Lassarab Protects Nonhuman Primates From Lethal Disease, Gabrielle Scher, Catherine Yankowski, Drishya Kurup, Nicole Josleyn, Eric Wilkinson, Jay Wells, Jesse Steffens, Ginger Lynn, Sean Vantongeren, Xiankun Zeng, Nancy Twenhafel, Kathleen Cashman, Matthias Schnell

Department of Microbiology and Immunology Faculty Papers

Lassa fever virus (LASV), a member of the Arenavirus family, is the etiological agent of Lassa fever, a severe hemorrhagic disease that causes considerable morbidity and mortality in the endemic areas of West Africa. LASV is a rodent-borne CDC Tier One biological threat agent and is on the World Health Organization's (WHO) Priority Pathogen list. Currently, no FDA-licensed vaccines or specific therapeutics are available. Here, we describe the efficacy of a deactivated rabies virus (RABV)-based vaccine encoding the glycoprotein precursor (GPC) of LASV (LASSARAB). Nonhuman primates (NHPs) were administered a two-dose regimen of LASSARAB or an irrelevant RABV-based vaccine to …

Comprehensive Investigation Into The Molecular Mechanisms Driving The Emergence Of Emm4 Group A Streptococcus, Chioma Odo, Samuel A Shelburne, Anthony R. Flores, Steven J Norris, Anna Konovalova, Blake Hanson

Dissertations and Theses (Open Access)

Abstract

Comprehensive Investigation into the Molecular Mechanisms Driving the Emergence of emm4 Group A Streptococcus

Chioma Modeline Odo, M.S.

Advisory Professor: Samuel A. Shelburne, MD, Ph.D.

The major gram-positive bacterium group A Streptococcus (GAS) is a model organism for studying microbial epidemics as it is well known to cause infections that occur in waves. GAS strains are grouped based on the composition of the N-terminal sequence of the M protein which is encoded by the emm gene. With the advent of large-scale whole genome sequencing, GAS clonal emergence events in emm1, emm3, and emm89 types have been identified …

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 …

Host-Microbiome Interactions In The Teleost Brain, Amir Mani Varnoosfaderani

Biology ETDs

This dissertation investigates host-microbial interactions within the teleost brain, previously considered sterile. Reviewing current literature highlights significant gaps in understanding teleost brain immunity, despite prevalent neurotropic diseases. We mapped the immune profiles of rainbow trout brains and meninges, revealing the olfactory bulbs as the immune effector part of the brain and the optic tectum as a nod2 expression hub. High il6 and il10 levels were noted in the telencephalon. A persistent bacterial community within healthy salmonid brains shares diversity with gut and blood microbiota. Brain bacterial isolates exhibit genomic signatures for brain colonization and polyamine biosynthesis. The microbiota shifts across …

Establishment Of Bacteroides In The Gut And Its Role In The Cystic Fibrosis Gut-Lung Axis, Rebecca A. Valls

Dartmouth College Ph.D Dissertations

In the quest to understand the complex interplay between the gut microbiota and cystic fibrosis (CF), a disease characterized by chronic upper respiratory complications and an exacerbated proinflammatory response, our lab engaged in a collaborative study with Dartmouth-Hitchcock Medical Center (DHMC) to characterize the gut microbiota of pediatric CF patients. Initial analyses established a connection between gut microbial composition and respiratory health, particularly highlighting a scarcity of Bacteroides species compared to healthy controls. In following investigations, we utilized random forest models to understand how stool microbiota may influence clinical outcomes of these pediatric CF patients, including: age, upper respiratory infections, …

A Potential Of Watercress Nasturtium Officinale Bioactive Compounds In Inhibiting Infectious Myonecrosis Virus (Imnv) By Targeting Rna-Dependent Rna Polymerase (Rdrp) Virus From Several Countries: In Silico Approach, Qurrota A’Yunin, Fatchiyah Fatchiyah, Maftuch Maftuch, Feri Eko Hermanto, Muhammad Hermawan Widyananda, Narendra Santika Hartana, Muhaimin Rifa’I, Yoga Dwi Jatmiko

Karbala International Journal of Modern Science

Infectious myonecrosis virus (IMNV) disease causes mass mortality and decreased shrimp production. The RdRp region projects to the interior, where it may function in transcription. The focus of this study was to determine the effect of amino acid polymorphisms from several countries on the structure of RdRp and identify the potential of watercress in inhibiting IMNV by targeting the RdRp protein of IMNV through an in silico approach. The results showed that the structure of the IMNV RdRp protein from Indonesia was similar to Mexico, and the protein structure from India_QDN was identical to India_QIL. Ligand binding affinity values showed …

Impact Of Toll-Like Receptor 10 Mutations On Tuberculosis Infections, Adriana Nicole Rafael, Sangman Kim

Master's Theses

Tuberculosis (TB), caused by the intracellular pathogen Mycobacterium tuberculosis (M. tb), is a leading global health crisis causing millions of cases and deaths each year. Though it affects individuals of any race, ethnicity, or cultural group, research shows the disease disproportionately affects individuals with Asian ancestry. Immunity to M. tb starts with its recognition by pattern recognition receptors such as Toll-like receptors (TLRs), which are key players in immune responses. TLR-10, an understudied toll-like receptor due to its inability to be studied through mouse models, is thought to play a key role in the clearance of inflammatory diseases. SNP I775V, …

The Physiological Significance Of Nitric Oxide Synthase In Staphylococci, Ryan M. Singh

Theses & Dissertations

Staphylococci, particularly Staphylococcus epidermidis, are common causes of implant-associated infections that may result in notable morbidity and mortality. One of the ways the innate immune system attempts to combat these invading pathogens is via the respiratory burst, in which free radical species such as nitric oxide (NO^•), toxic to bacterial respiration, are released in large quantities. Despite the toxicity of NO^•, some bacteria, including staphylococci, encode an endogenous bacterial nitric oxide synthase (bNOS), whose physiological role has been unclear until now. In this dissertation, we demonstrate that S. epidermidis is able to overcome the toxicity …

Pipecolic Acid And Novel Insights Into Cerebral Malaria, Akua E. Mensah

Theses and Dissertations

Cerebral malaria (CM), a severe manifestation of Plasmodium infection, prompts our investigation into the nuanced role of pipecolic acid in its pathophysiology. To unravel the molecular intricacies, we conducted in vitro lysine labeling techniques of mice infected with P. berghei ANKA parasites, and human P. falciparum grown in vitro, aiming to discern the impact of Plasmodium on pipecolic acid production. Previous observations indicated an elevation in pipecolic acid levels correlating with neurological decline in children with CM. In our study, confirming elevated pipecolic acid presence in the plasma and brain tissues of CM patients and the animal model of CM, …

Antimicrobial Activity Of Cat Flea (Ctenocephalides Felis) Gut Proteins On Different Days After Blood Feeding, Dhruva K. Karnik

Honors College Theses

Cat fleas (Ctenocephalides felis) are a blood-feeding ectoparasitic insect and a common domestic pest found throughout the world. Because of their reliance on host blood, fleas are exposed to blood-borne pathogens; however, the flea gut lumen is a hostile environment for microbial colonization. For example, the gut epithelia differentially express immune genes in response to feeding. In the present study, we measured the antimicrobial activity of gut proteins from cat fleas at different days after feeding (2, 5, 7, and 14). Dissected flea guts were homogenized, passed through a syringe filter, and measured in a protein assay kit. …

Investigating Vital Neutrophil Extracellular Trap Pathogen Response In Neutropenic Individuals, Ryan Illig

Thinking Matters Symposium

Neutrophils, also called polymorphonuclear leukocytes (PMNs), constitute the majority of innate immune cells. These cells possess a complex arsenal of functions that allow them to detect and eliminate a broad spectrum of pathogens. Neutropenia is characterized by decreased levels of neutrophils in the bloodstream, typically falling below the normal range. Moderate to severe neutropenia can increase the risk of pathogenic infections and without treatment can be life-threatening. Although the concentration of neutrophils in neutropenic individuals is decreased, upon activation, neutrophils still release neutrophil extracellular traps (NETs). NETs are pivotal in combating a spectrum of pathogens through their non-selective nature. Overreactive …

Cultivating Excellence: A Literature Review On Harnessing The Power Of The Gut Microbiome For Athletic Performance, Maya Katharine Dean

Honors Projects

The interplay between our gut microbiome and health is immense. This literature review analyzes the current research assessing the interplay between gut microbiome and athletic performance. Knowing how to improve gut microbial diversity via nutrition and supplementation can take athletic performance to the next level; namely improvements in immune, mental, and physical health.

An Exploration Of The Effectiveness Of Xanthorrhiza Simplicissima And Its Secondary Alkaloids As Antibiotics Against Staphylococcus Aureus With The Use Of Reserpine, Donald Bothe, Savita Chaurasia

Undergraduate Theses

Xanthorhiza simplicissima is a plant that is steeped in medical history. It has been used for hundreds of years by the Native Americans, and later by the Europeans, of Appalachia for its medicinal properties. One of the most useful medical applications of this plant are its antibiotic properties, as typified by its use as a tea that was consumed to treat mouth sores. These antibiotic properties can be attributed to some of its secondary alkaloids such as berberine, liriodenine, oxyacanthine, and magnoflorine. These compounds have been studied in other systems; however, oxyacanthine and magnoflorine have not been researched in tandem …

Monophosphoryl Lipid A-Based Adjuvant To Promote The Immunogenicity Of Multivalent Meningococcal Polysaccharide Conjugate Vaccines, Kishore Alugupalli

Department of Microbiology and Immunology Faculty Papers

Activation of the adaptive immune system requires the engagement of costimulatory pathways in addition to B and T cell Ag receptor signaling, and adjuvants play a central role in this process. Many Gram-negative bacterial polysaccharide vaccines, including the tetravalent meningococcal conjugate vaccines (MCV4) and typhoid Vi polysaccharide vaccines, do not incorporate adjuvants. The immunogenicity of typhoid vaccines is due to the presence of associated TLR4 ligands in these vaccines. Because the immunogenicity of MCV4 is poor and requires boosters, I hypothesized that TLR4 ligands are absent in MCV4 and that incorporation of a TLR4 ligand-based adjuvant would improve their immunogenicity. …