Determining The Impact Of Surface Roughness On Disinfection Efficacy Of Commercial Products Against Pseudomonas Aeruginosa And Staphylococcus Aureus Wet Surface Biofilms, Kayley Stallings

All Theses

Biofilms are resistant to many stressors including disinfectant treatments. Disinfection may be further complicated by biofilms formed on damaged surfaces, as the damaged parts provide bacteria a better place to attach and grow. To better understand the risks, a new method to standardize surface scratching, to emulate worn surfaces via surface roughness changes was developed. These surfaces were used to grow biofilms with an adapted standardized EPA method to determine disinfection efficacy differences on scratched and non-scratched high-density polyethylene (HDPE) and stainless steel (SS) coupons treated with commercial disinfectants [hypochlorite (CL)-based, hydrogen peroxide (HP)-based, and quaternary ammonium (QA)-based]. Post-80 grit …

In Vitro Assessment Of The Antihistomonal Activity Of Methyl Jasmonate And Jasmonic Acid, Mckayla B. Williams

Poultry Science Undergraduate Honors Theses

Histomonas meleagridis is a protozoan parasite and the causative agent of histomonosis in gallinaceous birds. There are currently no approved prevention or treatment options available for histomonosis control in the United States. Mortality in affected turkey flocks can exceed 80% which highlights the urgent need for research investigating novel strategies to mitigate histomonosis in the field. The objective of this study was to evaluate the in vitro antihistomonal and antibacterial effects of of methyl jasmonate (MeJA) and jasmonic acid (JA), two plant-derived compounds, in a xenic culture of H. meleagridis. Assays were conducted using cultured H. meleagridis (PHL strain) treated …

Microbial Guardians Of The Savannah: Unraveling The Gut Microbiome For African Carnivore Conservation, Laura E. Peirson

All NMU Master's Theses

Non-invasive fecal sampling is essential for wildlife gut microbiome (GMB) research, yet field conditions often limit preservation options. I compared gut bacterial communities in paired fecal samples preserved in stabilization tubes and air-dried in paper bags collected from anesthetized African lions (Panthera leo) and spotted hyenas (Crocuta crocuta) in Etosha National Park, Namibia. Additional opportunistic samples from carnivore kill sites were also analyzed. No significant differences in alpha or beta diversity were detected between preserved and dried samples, although bacterial beta diversity differed between preserved and opportunistic samples (PERMANOVA). Core bacterial communities remained consistent across sample …

Role Of Cellular Proteins In The Regulation Of Herpes Simplex Virus Type 1 Gene Expression And Dna Replication, Joseph R. Heath

Electronic Theses and Dissertations

Herpes simplex virus type 1 (HSV-1) is a ubiquitous human pathogen that infects the majority of the human population. To facilitate infection, this virus relies on a combination of host and viral factors. Previous studies have revealed a number of host proteins that associate with the HSV-1 genome throughout infection but their putative role(s) in this process remain undefined. This study aims to examine two such proteins to determine their contributions to HSV-1 gene expression and DNA replication. The first of these factors is Ints3, a subunit of the Integrator complex. This protein complex functions in transcription regulation, and Ints3 …

Long-Chain Fatty Acids Promote Candida Albicans Gut Colonization By Restructuring The Fungal Cell Surface, Musfirat Shubaita

Dissertations and Theses (Open Access)

Long-chain fatty acids promote Candida albicans gut colonization by restructuring the fungal cell surface

Musfirat Shubaita, BS

Advisory Professor: J. Christian Perez, Ph.D.

The yeast Candida albicans is a facultative anaerobe residing in the human digestive tract. Although fungal genetic determinants of mammalian host colonization have been identified, little is known about signals and molecules in the intestinal environment that influence C. albicans proliferation. Previously unpublished data from the Perez lab showed that oleic acid, one of the most abundant long-chain fatty acids in nature, promotes C. albicans colonization of the murine intestine. The goal of this research is to …

Microbial Metabolite Regulation Of Microglial Ahr Signaling In Alzheimer’S Disease, Ghalya E. Alrousan

Dissertations and Theses (Open Access)

Introduction: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by amyloid-β plaque accumulation, neuroinflammation, and cognitive decline. Recent evidence suggests that systemic factors, particularly the gut microbiota and its metabolites, play a significant role in shaping brain immune responses, including microglial activation. However, the mechanisms linking gut dysbiosis to microglial dysfunction in AD are poorly understood. The aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor responsive to tryptophan metabolites, has recently gained attention as a key regulator of neuroinflammation and microglial function. I hypothesize that the loss of beneficial microbial AHR ligands, specifically indole derivatives, during aging and AD …

Distribution, Roles And Environmental Drivers Of Bacterial Communities In The Chesapeake And Delaware Bays, Mir Alvee Ahmed

All Dissertations

In this dissertation, water samples from the Chesapeake and Delaware Bay estuaries were analyzed to see how estuarine environmental gradients drive distributions, functional potential, growth estimates and gene expressions of bacteria. To answer this, the abundant and versatile taxa– Rhodobacterales and Actinobacteriota, along with broader particle-attached (PA) vs. free-living (FL) bacterial assemblages of these Bays were analyzed using a multifaceted ‘omics approach.

The PA fraction, differing from the FL in taxonomy, distribution, functional potential and estimated growth rates across salinities, and bays harbored genes degrading complex aggregates, and surface attachment. The FL counterpart presented genes involved in nutrient uptake …

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 …

The Inside Scoop: Elucidating The Three-Way Relationship Between Schistosoma Mansoni, The Gut, And Vaccines, Mariam A. Mhanna

Biomedical Sciences Theses & Dissertations

Schistosomiasis is a neglected tropical disease that affects over 250 million people worldwide. This blood fluke infection burdens communities and areas with limited to no access to clean fresh water. When a host is exposed to cercariae, the infectious agent, in a body of water, it matures in the host’s circulation into adult female and male worms. Copulated adult worms migrate to the mesentery, in the case of Schistosoma mansoni, and produce eggs that can cross the intestinal barrier and get excreted in the feces to continue the lifecycle. The effects of S. mansoni infection on the host …

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 …

Advanced Analytical Biosensing For Cancer Detection And Neural Diagnostics Using Tapered Optical Fiber (Tof), Protonic, And High Throughput Microplate –Based Technologie, Bayan Hassan Alharbi

Chemistry & Biochemistry Theses & Dissertations

This dissertation investigates the development and application of advanced biosensing technologies to enhance early disease detection, neurological diagnostics, and bioactive compound evaluation. The research spans four key areas. First, it introduces tapered optical fiber (TOF)-based plasmonic biosensors for the non-invasive detection of prostate cancer, demonstrating high sensitivity and specificity compared to conventional diagnostic methods.

Second, it explores the use of fluorescent biosensors to test the Transmembrane Electrostatically Localized Proton (TELP) theory, shedding light on the role of localized protons in neuronal signaling and energy transfer. Third, the work presents a high-throughput, microplate-based biosensing platform for analyzing mitochondrial function under nanosecond …

Microbial And Ecophysiological Indices Of Agricultural Soils As Affected By Different Farming Practices In Tropical Monsoon Climate, Gulshan Ara Begum, Sajal Roy, Nasrin Chowdhury

Journal of Environmental Science and Sustainable Development

Organic farming is increasingly promoted as a sustainable alternative to conventional agriculture due to its positive effects on soil microbial dynamics, a critical component of ecosystem functioning. However, empirical comparisons of microbial responses across these systems are scarce. Therefore, we conducted a study to assess the various microbial indices of soils taken from distinct crop fields (e.g., brinjal, chilli, tomato, bean, and fallow lands) managed under both conventional and organic farming techniques. Composite soil samples from surface layer (0–15 cm) were collected in a completely random way from Bandarban upazila of Bangladesh (22°11'24.0"N 92°09'00.0"E, organic fields; 22°10'12.0"N 92°09'36.0"E, conventional fields). …

In Silico Prediction Of Cytotoxic T-Cell Epitopes From Helicobacter Pylori Virulence Factors Using An Immunoinformatics Approach, Demy Valerie Chacon, Kiana Alika Co, Daphne Noreen Enriquez, Aubrey Love Labarda, Reanne Eden Manongsong, Edward Kevin B. Bragais

Biology Faculty Publications

Background: Helicobacter pylori infects approximately half of the global population, leading to gastric and duodenal ulcers. Despite the availability of antibiotics, challenges such as patient reluctance, high treatment costs, and antibiotic resistance limit their effectiveness, making vaccination a promising alternative. This study used immunoinformatics to identify candidate epitopes for a multiepitope vaccine construct against H. pylori.

Material and methods: The protein variability server was utilized for conservation analysis. The epitopes were screened for antigenicity, allergenicity, toxicity, cross-reactivity, and population coverage. Selected epitopes were docked with their corresponding human leukocyte antigen (HLA) alleles, and thermodynamic quantities were determined. Five virulence …

Utilizing The Combinatory Power Of Chemotherapeutic Compounds In Triple Negative Breast Cancer Cells, Matthew I. Hyder

Biology Summer Fellows

Breast cancer is the leading cause of cancer-related deaths among women worldwide and the second most common cause of cancer deaths in women in the United States. Genetic variants that increase the risk of breast cancer include mutations in the breast cancer susceptibility genes 1 and 2 (BRCA1 and BRCA2). Apoptosis, or programmed cell death, is a natural process that helps the body remove aged cells. However, in cancer, deregulated apoptotic signaling—especially the activation of anti-apoptotic mechanisms—enables cancer cells to evade this process, leading to uncontrolled proliferation, tumor survival, therapeutic resistance, and cancer recurrence. Most anti-cancer drugs function as chemotherapeutic …

Bridging Prairie Restoration And Regenerative Agriculture With Compost Tea, April Hersey

2025 Symposium

Inland Pacific Northwest prairie is an endangered ecosystem that has been reduced by conversion to agriculture. There is growing interest in the role of soil microorganisms in prairie ecosystems, which may be crucial for restoration of the plant community through interspecies interactions within the soil near plant roots. One method for improving soil microorganism community composition is compost tea: enriched liquid compost extract. Compost tea is used in regenerative agriculture to improve crop yields and protect against pathogens, ostensibly through the activity of the added compost microbes. While research has supported compost tea application in regenerative agriculture, it has not …

Elucidation Of A Role In Biofilm Production For The Tyrosine Catabolism Pathway In Vibrio Cholerae And Analysis Of Reversible Phase Variation In Vibrio Vulnificus, Aheli S. Mukerji

LSU Doctoral Dissertations

Biofilms produced by the cholera pathogen Vibrio cholerae not only enhance its ability to survive in the environment but also allow pathogenic success of the bacterium. This organism also undergoes phase variation, switching between smooth and rugose colonial phenotypes, the latter forming much more vibrio polysaccharide (VPS) resulting in more robust biofilms and subsequently having an increased level of persistence. In a previous study, many genes were found to be upregulated in the transition from the smooth to the rugose phenotype. Here, several of these upregulated genes were investigated for their potential role in biofilm production, and an additional gene, …

The Astrobiological Figure Of Humboldt As Pioneer In The Rock Varnish Research, Jose Jordan-Soria

Homage to Alexander von Humboldt: Travels to and from Spain Throughout the Centuries / Homenaje a Alexander von Humboldt: Viajes hacia y desde España de todos los siglos

From Humboldt is particularly interesting -and little know- his description of mineral coatings on rocks 200 years ago, reported in his book Personal Narrative of Travels to the Equinoctial Regions of the New Continent during the years 1799-1804, co-written with Aimé Bonpland, for which is considerate the father of rock coating research. On June 5th 1799 set sail from A Coruña -Spain- to Cumaná -Venezuela- beginning five years of expedition. While they explored the Orinoco River system, in th eriver basin waterfalls, Humboldt observed the presence of dark coating depositions. He ascertained a manganese-rich accretion, reporting similar structures in other …

Commentary On Blaser's "Antibiotic Use And Its Consequences For The Normal Microbiome", Fred C. Tenover

AMR Commentary

If you have not read this eye-opening commentary by Dr. Martin Blaser about the negative impact of the widespread use of antibiotics in children, you should. The goal of giving antibiotics to children usually is to treat an infection — an earache, a respiratory tract infection, or perhaps a potentially deadly bloodstream infection. Those antibiotics, however, will often kill more than just the bacteria that are causing the infection. Humans have large quantities of “good bacteria” in our intestinal tracts, on our skin, and elsewhere on our body that play an important role in keeping us healthy.

Skin Bacteriome Structure And Batrachochytrium Dendrobatidis Prevalence Differs Amongst Two Sympatric Salamanders In The San Francisco Bay Area., Aria Norwood, Jadyn Jamora, Micuel Madison, Jamiee Nguyen, Azan Yousaf, Katya Morales, Emily Vu, Obed Hernández-Gómez

Natural Sciences and Mathematics | Student Professional Publications

Microbial surveys are becoming an important component of wildlife health research, especially in cases where environmental change and infectious diseases are serious issues. Amongst amphibians, Batrachochytrium spp. have the potential to be fatal pathogens that can impact the population health of numerous species. We assessed the skin bacteriome, prevalence of Batrachochytrium dendrobatidis (Bd) and body conditions of two salamander genera with different life histories: the California slender salamander (Batrachoseps attenuatus) and members of the Pacific newt species complex (Taricha torosa and Taricha granulosa; Taricha sp.). We used 16S rRNA V4 amplicon sequencing to characterise the bacterial communities. Taricha sp. had …

Reaction Control Mechanism In Deoxyuridine 5'-Triphosphate Nucleotidohydrolase, Aaron Delay

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

Deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) is an enzyme involved in the pyrimidine biosynthesis pathway, a key component of cellular DNA metabolism. It regulates intracellular uracil carrying triphosphate levels by hydrolyzing dUTP, thereby providing a substrate for thymidylate synthase (TS). The effective inhibition of dUTPase is expected to enhance TS-targeted chemotherapy by promoting thymine-less apoptosis.

Although the reaction mechanism of dUTPase has been studied, the human nuclear homotrimeric form remains complex, as all three subunits cooperatively form a single active site. As a result, the detailed molecular dynamics of its catalysis are still not fully understood. In this study, I investigated the …