Observing Antibiotic Resistance In Bacterial Co-Cultures Under Simulated Microgravity, Tyler Jenkins, Marina Vaden

Discovery Day - Daytona Beach

Bacteria grow in complex natural environments with multiple factors affecting their growth, metabolism, and physiology. While astronauts are still preparing to travel to Mars, scientists must learn how to simulate a more realistic Martian environment. While a small volume of publications investigates the independent effects of microgravity or Martian regolith on microorganisms (Liao et al., 2025; Allen et al., 2022; Naz et al., 2023; Duri et al., 2025), to our knowledge no current experiments exist on the joint effects of microgravity and Martian simulant on a co-culture. This experiment aims to investigate the effect of a microgravity analog on the …

Systemic Infection Of Beauveria Bassiana In A Stranded Endangered Green Turtle Chelonia Mydas: A Case Report, Ming-An Tsai, I-Chun Chen, Tsung-Hsien Li

The Thai Journal of Veterinary Medicine

The green turtle (Chelonia mydas) is the most frequently encountered marine turtle species in Taiwan. This study describes the postmortem findings of a juvenile green turtle with injuries to the right foreflipper that was rescued off the Taiwan coast and died after 3 months in rehabilitation. Necropsy revealed large, yellow, multifocal caseous lesions involving the right foreflipper, spleen, liver, kidneys, and lungs. Fungal infection of Beauveria bassiana was confirmed by culture, morphological and molecular characterization, phylogenetic analysis, and histopathological examination. This report provides evidence that B. bassiana is associated with a systemic fungal infection which can be fatal …

An Investigation Of Entamoeba Histolytica Chitin Synthases And Other Encystation Factors In Early Encystation, John N. Talledo

All Theses

Entamoeba histolytica is a food-and-water-borne human protozoan pathogen that relies on a two-stage life cycle for successful proliferation outside of the host. E. histolytica exists in its dormant cyst form while outside of its host and converts to the motile trophozoite (amoeba) form in the small intestine. The trophozoites colonize the large intestine to cause symptomatic disease in ~10% of infections, resulting in ~100 million cases of amoebic dysentery each year. Trophozoites can convert back to the cyst form, which is shed in feces to continue the infection cycle.

Currently, there is a lack of understanding of the exact molecular …

Understanding The Role Of Toxs As A Bile Sensing Component Of The Toxrs Virulence Regulatory System In Vibrio Spp., Minje Kim

Dartmouth College Ph.D Dissertations

Pathogenic Vibrio bacteria, such as V. cholerae and V. parahaemolyticus, colonize in the human small intestine to cause severe gastrointestinal disease. During the infection, these bacteria encounter bile salts, antimicrobial cholesterol metabolites secreted into the intestine. Pathogenic Vibrio species have evolved to utilize bile salts as signals to regulate virulence. The signaling depends in part on ToxRS, a conserved co-component transmembrane transcription regulator. ToxRS consists of the transcription factor ToxR and its membrane-tethered binding partner ToxS. ToxS is required for ToxR stability and full transcriptional activity. Although bile salts are known to influence ToxRS-dependent virulence gene expression, the molecular …

Tlr3 Mediated Type I Interferon Response In Mammalian Cell Defense Against Cryptosporidium Parvum Infection., Anjelica Matias

Biochemistry and Molecular Biology

Cryptosporidium parvum is a major cause of a diarrheal disease which affects many children in the USA as well as the rest of the world, yet the contribution of its double stranded RNA (dsRNA) viral symbiont, Cryspovirus (CSpV1) to host innate immunity remains unclear. This study investigated whether CSpV1 activates Toll Like Receptor 3 (TLR3) signaling pathways and downstream Interferon type I (IFN I) responses in mammalian intestinal epithelial cells. Confluent Human Ileocecal Colorectal Adenocarcinoma cells (HCT8) were exposed to CSpV1, and the expression levels of Tumor Necrosis Factor Receptor-Associated Factor 3 (TRAF3), Nuclear Factor-𝜅-light chain enhancer of activated B-cells …

Surveillance Of A Novel Vesivirus Discovered In An Urban Mephitis Mephitis Population, Amanda E. Diggins

Honors Theses and Capstones

Caliciviridae is a family of non-enveloped, positive-sense, single stranded RNA viruses, including eleven defined genera that contain important pathogens of humans and animals. Within the Caliciviridae family, the genus Vesiviridae includes feline calicivirus, a leading cause of upper respiratory disease in cats, and vesicular exanthema of swine virus, a historical disease of domestic swine that has now been implicated in several marine mammal vesicular diseases, one of which has been confirmed zoonotic. Urban landscapes create a unique environment for rapid intra- and interspecies transmission of viruses. Clustered resources attract high-density populations of synanthropic wildlife species, increasing spatial overlap and heightening …

The Role Of Tumor Microenvironment In Glioblastoma Multiforme(Gbm) Therapeutic Resistance, Kwesi E. Taylor

Master's Theses or Doctor of Nursing Practice

Despite significant advances in cancer research and treatment, Glioblastoma multiforme (GBM) remains one of the most difficult cancers to treat effectively, with minimal improvement in long-term survival rates over the past few decades. This is largely attributed to tumor heterogeneity and the ability of tumor cells to develop adaptive resistance mechanisms supported by the tumor microenvironment (TME). Although the TME is recognized as a key contributor to tumor progression and therapeutic resistance, the underlying molecular pathways and regulatory genes remain incompletely understood. This study investigated the role of the tumor microenvironment in GBM therapeutic resistance using a bioinformatics approach. Single-cell …

Repurposing Cyclin-Dependent Kinase Inhibitors For The Discovery Of Novel Antiplasmodial Compounds, Ritam Bhowmik

Honors Undergraduate Theses

Malaria remains a major global health burden with over 282 million cases annually and rising resistance to artemisinin-based combination therapies. Plasmodium falciparum, the most lethal malaria parasite species in humans, relies on tightly regulated cell cycle progression during replication within red blood cells. Cyclin-dependent kinases (CDKs) are central regulators of eukaryotic cell division and transcription, and several CDK-like enzymes in P. falciparum, including Pfmrk and PfPK6, are essential for parasite growth and structurally distinct from human kinases. This study evaluated whether commercially available human CDK inhibitors (CDKIs) targeting cancer pathways could be repurposed as novel antimalarial compounds. A library of …

Adiponectin-Regulated Macrophage Responses In Aspergillus Fumigatus Infection: Mechanisms Of Uptake And Killing, Sri Harshini Goli

All-Inclusive List of Electronic Theses and Dissertations

Invasive aspergillosis (IA), caused by Aspergillus fumigatus, is a life-threatening infection in immunocompromised individuals, necessitating novel host-directed therapies. Macrophages are pivotal in antifungal defense, yet their function can be dysregulated; the influence of the adipokine adiponectin (APN) on this process is not fully understood. This thesis investigated the role of APN signaling in alveolar macrophage (AM) and bone marrow-derived macrophage (BMDM) responses to A. fumigatus and assessed the therapeutic potential of the APN receptor agonist, AdipoRon. Initial studies revealed that genetic deficiency in APN or its receptors renders AMs intrinsically pro-inflammatory and significantly impaired fungicidal activity against A. fumigatus. Subsequent …

Orchestrated Architecture Dismantling: Borrelia Burgdorferi’S Coordinated Destruction Of Adaptive Immune Responses, Craig A. Land

Electronic Theses and Dissertations

Borrelia burgdorferi represents the most prevalent vector-borne bacteria in North America, affecting ~476,000 Americans annually yet persisting despite robust immune responses. This project reveals spirochetes target adaptive immunity through coordinated lymphatic colonization and precision immune dysregulation.

Using comparative host models (C57BL/6 vs. reservoir Peromyscus leucopus), we demonstrate lymph node colonization within 48-hours, with spirochetes exploiting LYVE-1-positive lymphatic structures as dissemination highways while avoiding the interior of follicular regions. Critically, we identify targeted CD4+ T-cell elimination in germinal center border zones at 21-DPI, precisely when these cells should be coordinating protective immunity. Concurrent upregulation of inhibitory receptor CD32b creates molecular …

The Impact Of Polymycovirus 1 On Aspergillus Fumigatus Pathogenesis During Lung Infection, Alexander W. Rapp

Dartmouth College Ph.D Dissertations

The genus Aspergillus comprises over 250 species of fungi. Within this genus, only a handful of species cause disease in humans. One species is Aspergillus fumigatus (A.f.), an environmentally ubiquitous, saprophytic fungal pathogen. Lung infections due to A.f. range from invasive infection to allergic forms of the disease. Allergic bronchopulmonary aspergillosis (ABPA) is one of the most severe forms and presents as a hypersensitivity that often results in off-target damage to the surrounding airways. Patients with ABPA are sensitized to fungal antigens and this is commonly seen in cystic fibrosis and genetic predispositions. Recent data from our lab shown how …

Characterization Of Sars-Cov-2 Replication And Transcription Complexes Via Structural And Evolutionary Approaches, Amelie Ghirardo, Ben Shabatian, Avishai Aghelian, Kyle Tau, Eleonora Gianti

Undergraduate Research

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused around 700M cases and over 7M COVID-19-related deaths recorded worldwide (World Health Organization, March 2025). Aiming to effectively combat this and other disease-causing Coronaviruses (CoV), unprecedented research efforts led to the development of new vaccines and antiviral therapies. Due to emergence of variants of concern (VOCs) with increased transmissibility, immune evasion from vaccination, and potential to resist the available treatments, SARS-CoV-2 continues to represent a major threat to global health. Hence, there is a pressing need to discover new antivirals with broad-spectrum efficacy against multiple SARS-CoV-2 variants and related CoVs. This project …

Impact Of Temperature And Microbial Infection On The Honey Bee Hemocytes, Michael E. Oeth

Master's Theses

Introduction

Honey bees (Apis mellifera) rely on hemocytes for immunity, wound healing, and hemolymph homeostasis. While 32°C reflects optimal hive conditions, suboptimal temperatures (22°C) and stressors like pathogens (Varroa destructor, bacteria) or pesticides impair hemocyte function. Using clodronate liposomes (CLD) to deplete hemocytes, we assessed how immune suppression interacts with these stressors.

Methods

Newly emerged (5-day-old) and older (15-day-old) bees were assigned to: CLD, control liposomes (LP), PBS, injection wound, or no treatment. Cohorts were exposed to 32°C (optimal) or 22°C (stressful for non-immunosuppressed bees). Fifteen-day-old bees were challenged with Escherichia coli or Staphylococcus aureus. Survival, hemolymph volume, and hemocyte …

Mechanisms Of Behavioral Change In Hosts Of Toxoplasma Gondii: A Review, Olivia Grimsley

Senior Honors Theses

The parasite Toxoplasma gondii is a highly ubiquitous parasite that latently infects an estimated 33% percent of the global population. Toxoplasmosis is of obvious clinical significance due to the extremely high risks to the unborn who contract it congenitally. Less attention has been given to a more subtle aspect of latent infection, which is the behavioral alterations that are commonly experienced by those who contract the parasite. Infected individuals commonly display a variety of altered behaviors, such as increased aggression and risk-seeking behaviors, depression, higher tendency towards suicide and self-directed violence, a loss of fear response, and a greatly increased …

Neutrophil Inflammatory Death Regulation By Bacterial Type Iii Secreted Effectors, Arianna D. Reuven

Dartmouth College Ph.D Dissertations

Yersinia and Pseudomonas use a T3SS to secrete effectors into host cells that inhibit phagocytosis and modulate immune responses, such as inflammasome activation. Inflammasomes promote the activation of the proinflammatory protease caspase-1. The activation of an inflammasome sensor in response to a signal or ligand initiates the assembly of the inflammasome leading to activation of caspase-1 which cleaves GSDMD and pro-inflammatory cytokines IL-1β and IL-18 into their mature forms. As neutrophils are recruited in large quantities to sites of infection, they are excellent candidates to drive inflammasome dependent responses. Neutrophils have been shown to produce multiple inflammasomes, like pyrin and …

Development Of A Multi-Epitope Peptide Vaccine Against Monkeypox Virus: Immunoinformatics Analysis For South East Asian Hla Alleles, Nelson Chandra, Mochammad Aqilah Herdiansyah, Viol Dhea Kharisma, Arif Nur Muhammad Ansori, Arli Aditya Parikesit

Makara Journal of Science

The monkeypox virus (MPXV), a DNA virus causing zoonotic disease, poses major global public health challenges, with mortality rates between 3%–6%. Although smallpox vaccines provide partial cross-protection, there is a critical need for a dedicated, effective monkeypox (mpox) vaccine. This study aimed to design a multi-epitope peptide-based vaccine specifically adapted to the HLA allele profiles common in Southeast Asian populations, where MPXV cases are rising. Using immunoinformatics, we screened for and detected B and T cell epitopes from the MPXV cell surface antigen and IFN-alpha/beta receptor proteins. The vaccine design was validated through a rigorous evaluation of its antigenicity, immunogenicity, …

Immuno-Bioinformatics Study Of Secondary Metabolites From Watercress Nasturtium Officinale As Immunostimulant In Whiteleg Shrimp Litopenaeus Vannamei By Targeting Peroxinectin And Scavenger Receptor Class B, Qurrota A’Yunin, Muhaimin Rifa’I, Maftuch Maftuch, Yoga Dwi Jatmiko, Muhammad Hermawan Widyananda, Triyanto Triyanto, Muhammad Tegar Handrianto

Karbala International Journal of Modern Science

The viral disease affects the whiteleg shrimp (Litopenaeus vannamei) and causes losses. Immunostimulants are recognized as a more environmentally friendly approach to disease management and antimicrobial properties of aquatic organisms. Watercress (Nasturtium officinale) is an aquatic plant species that contains antioxidant properties that can protect the organism from disease and boost the immune system. Shrimp rely heavily on innate immunity to combat infectious agents due to their absence of adaptive immunity. Peroxinectin and scavenger receptor class B (SRB) play essential roles in the shrimp defense system. This research employs a bioinformatic to assess the immunostimulatory potential …

Genetic Analysis Of Methionine Restriction-Associated Mitochondrial Unfolded Protein Response Signaling., Josh D. Dodge

Biology Dissertations - Archive

The lifespan of an organism is dictated by various genetic and environmental factors. One such determinant is the health of mitochondria which are organelles that mediate various critical cell functions including a significant role in generating the vast supply of cellular energy. Indeed, the gradual decline of mitochondrial function is believed to be a hallmark and possible cause of aging. Paradoxically, mild mitochondrial dysfunction early in life extends lifespan in various model organisms. Cells use diverse approaches to promote mitochondrial homeostasis, including the transcriptional reprogramming of cells by mitochondrial unfolded protein response (UPRmt) to mitigate mitochondrial stress. Consistently, UPRmt activation …

Impacts Of Tick Parasitism On The Rodent Gut Microbiome, Robert J. Brinkerhoff, Joshua Pandian, Meghan Leber, Isabella D. Hauser, Holly D. Gaff

Biological Sciences Faculty Publications

Host microbiota may impact disease vector behavior and pathogen transmission, but little is known about associations between ectoparasites and microbial communities in wildlife reservoir species. We used Illumina metagenomic sequencing to explore the impacts of tick parasitism on the rodent fecal microbiome in both a field and laboratory setting. We found that tick parasitism on wild hosts was associated with variation in the fecal microbiota of both the white-footed deermouse, Peromyscus leucopus, and the southern cotton rat, Sigmodon hispidus. In a lab experiment, we detected significant changes to the fecal microbiome after experimental exposure to immature ticks in …

Novel Infection By Mucor Hiemalis Kills Caenorhabditis Hosts Through Intestinal Perforation, Jay Ni

West Chester University Graduate Theses, Dissertations, and Final Projects

The nematode Caenorhabditis elegans has emerged as a popular model system to investigate cell biology and host-pathogen interactions. Presently, C. elegans is studied as a natural host of intracellular pathogens such as microsporidia and Orsay virus along with extracellular bacterial and fungal pathogens. The use of C. elegans as a model in host-pathogen research is limited by the number of naturally occurring pathogens to the organism. Through a sampling project to identify new pathogens of C. elegans, we identified the fungus Mucor hiemalis as a pathogen of Caenorhabditis species. We observed the fungus in the intestinal lumen of wild-caught …

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 …

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 …

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 …

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 …

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 …

Characterizing The Regulation Of Candida Albicans Hyphal Morphogenesis In The Context Of Host Macrophages, Hannah Wilson

Dissertations and Theses (Open Access)

Candida albicans is a commensal fungus that resides on the skin, mucosal surfaces, and in the gut of an estimated 80% of individuals. Though generally harmless, C. albicans is capable of causing uncomfortable mucosal infections as well as deadly disseminated infections depending on the immune status of the host. Although antifungal therapeutics exist, the mortality rate associated with disseminated disease still lingers around 50%. Further, C. albicans is the fourth most common cause of all bloodstream infections and continues to present as a major clinical issue with less than satisfactory treatment options. For this reason, it is imperative to understand …

The Development Of A Primer Payload With Microparticles For Uti Pathogen Identification Using Polythymidine- Modified Lamp Primers In Droplet Lamp, Jonas Otoo

KGI Theses and Dissertations

Nucleic acid amplification tests (NAATs) are among the diagnostic tests with the highest sensitivity and specificity. However, they are more complex to develop than other diagnostic tests such as biochemical tests and lateral flow immunoassay tests. Polymerase chain reaction (PCR) is the gold standard for NAATs. PCR requires thermal cycling to achieve clonal amplification of the target pathogen DNA for diagnosis. Thermal cycling poses a challenge in the development of PCR diagnostics for point-of-care (POC) settings. Loop-mediated isothermal amplification (LAMP) offers an isothermal method for NAATs diagnostics. The advancement of the microfluidics field significantly enhances the development of LAMP diagnostics …

Immunomodulatory Effects Of Resolvin D2 In A Model Of Infection, Prem Yugandhar Kadiyam Sundarasivarao

Graduate School of Biomedical Sciences Theses and Dissertations

Dysregulated hyperinflammatory host immune response to underlying bacterial infections is a characteristic of sepsis. In sepsis, bacteria often trigger abnormal hyperinflammatory responses which can cause multiple organ failure and if sustained can lead to an immunosuppressive phase where the host is susceptible to secondary infections caused by opportunistic bacteria like Pseudomonas aeruginosa (P. aeruginosa). In our studies, we used a 2-hit model of cecal ligation and puncture (CLP) followed by P. aeruginosa secondary lung infection to investigate cellular and molecular mechanisms in the beneficial action of resolvin D2 (RvD2). Resolvins of the D-series are a group of fatty acids known …