Biology Commons^™

An In-Depth Investigation Into Yersinia Pestis Phages: Isolating A Yersinia Pestis Phage From Soil And Constructing A Comprehensive Phylogenetic Analysis Of Known Yersinia Pestis Phages, Jacqueline Chavez

All HCAS Student Capstones, Theses, and Dissertations

Yersinia pestis, the causative agent of the plague, has become increasingly resistant to many antibiotics; therefore, alternatives such as phage therapy are necessary. Phage therapy uses combinations of bacteriophages or phages, which are viruses that only infect bacteria. However, phages—especially Y. pestis phages —are severely understudied. Thus, this research has sought to specifically isolate a phage from soil that infects Y. pestis. There were 146 samples that were collected from across the US, focusing on those with reported cases of plague. These samples were enriched with Y. pestis to maximize the amount of potential phage that target Y. pestis. …

Elucidating The Mechanism Of Interleukin-17a Signaling In The Pathogenesis Of West Nile Virus, Farzana Nazneen

Dissertations

West Nile Virus (WNV), a neurotropic flavivirus transmitted by mosquitoes, is a leading cause of viral encephalitis in the United States and remains a significant public health concern. Unfortunately, no vaccine or therapeutic intervention is available against WNV infection. Previous studies, including ours, demonstrated that interleukin-17A (IL-17A) signaling increases the cytotoxic potential of CD8⁺ T cells to facilitate WNV and parasite clearance; however, the molecular mechanism is not understood. IL-17 receptor C (IL-17RC) is an obligatory co-receptor with IL-17 receptor A (IL-17RA) for signaling induced by IL-17A, IL-17A/F, and IL-17F. In this study, we found that IL-17RC deficient ( …

Bioindicators Of Mercury In Riverine Systems, Kathryn Mudica

All-Inclusive List of Electronic Theses and Dissertations

This study focuses on the bioaccumulation and biomagnification of mercury in freshwater food webs, with emphasis on bioindicators, such as macroinvertebrates, crayfish, and river otters. Despite regulatory efforts and advancements in monitoring, significant gaps remain in understanding mercury dynamics in freshwater systems—especially regarding its transport, methylation, and bioavailability across different ecosystems. To address these knowledge gaps, this study adopts a biocentric approach, emphasizing the role of living organisms in their environment. By utilizing macroinvertebrates, crayfish, and river otters as bioindicators, we aim to assess mercury bioavailability and distribution. These organisms provide varying temporal and spatial scales of mercury accumulation, offering …

Analysis Of Microbiome In Various Human Medical Conditions Using Next-Generation Sequencing Of The 16s Rrna Gene, Pallavi Sharma

Electronic Theses and Dissertations

Studies of human microbiomics, spanning diverse anatomical sites, offer a unique perspective into the complex microbial communities within the body. Influenced by age, gender, and disease, it mirrors broader microbial ecosystems. This study specifically delves into the ocular and gastrointestinal tract microbiome, comparing its composition in 43 healthy and diseased patients using 16S rRNA gene sequencing. We identified a rich microbial landscape, identifying over 338 bacterial taxa. Notably, Acinetobacter, Cutibacterium, Acidovorax and Herbaspirillum were prevalent in the ocular samples and Akkermansia, Faecalibacterium, and Anaerostipes were mostly prevalent in gut samples. Moreover, dry eye disease conditions were characterized by …

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 …

Bodine: An Agent-Based Modeling Approach To Studying Localized Coexistence Across Environmental Heterogeneity, Alexandra Campbell

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Boosting The Power Performance Of Microbial Fuel Cells By Using Dual Nanomaterial-Modified Carbon Felt Electrodes, Krishna Thapa, Wenyan Liu, Yuwei Zhang, David J. Westenberg, Yishu Zhou, Risheng Wang

Chemistry Faculty Research & Creative Works

Innovative design enhancements to microbial fuel cells (MFCs) are pivotal for improving their viability as renewable energy sources. This study introduces a dual approach to electrode modification, integrating polyaniline (PANI) and gold nanoparticles (AuNPs) on carbon felt (CF) anodes coupled with a unique cathode composed of DNA origami and chitosan. The synergistic effect of PANI and AuNPs significantly increases the hydrophilicity and conductivity of the anode, leading to a considerable surge in power density. Concurrently, the biocompatible DNA origami and chitosan-functionalized cathode facilitates efficient electron transfer without relying on conventional catalysts. Together, these modifications yield a 52.42% increase in the …

What Drives Gut Microbial Diversity And Community Structure Among Closely-Related Host Species?, Rylee Jensen

All NMU Master's Theses

The gut microbiome (GMB) of mammals hosts an important community of microbes that perform countless micro-ecosystem services for the host and are influenced by numerous factors including host physiology, environment, and phylogeny. Phylogeny may have a unique effect on GMB diversity and community structure (i.e., a GMB profile) via phylosymbiosis, a theory in which the evolution of hosts matches the evolution of their associated microbiota. Elucidating phylosymbiosis in mammals is difficult because multiple intrinsic and extrinsic factors collectively drive individual GMB variation. Thus, there is a need to simultaneously analyze the role of physiology, environment, and phylogeny on shaping host …

Water Quality Of Silver Creek, A Buried Urban Stream, Nick Bultje, Valerie Krause, Rebecca Nulty

Student Papers and Reports

There are many sources of pollution that can affect a watershed. These pollutants can impact the water's pH, temperature, conductivity, and dissolved solids. Escherichia coli is a specific pollutant that comes from waste products of humans and animals. High levels of E. coli cause serious health problems. This study examines Silver Creek, a tributary within the Plaster Creek watershed. Silver Creek runs mostly underground and has storm drainage systems that flow into the creek. The goal was to explore the effects of the underground section of Silver Creek on water quality and E. coli levels. The water quality and levels …

Limits Of Longwood's Electron Microscope: A Study In Biological Imaging, Rachel Danzitz, Bjoern Ch. Ludwar

Fall Showcase for Research and Creative Inquiry

This study evaluates the imaging capabilities and limitations of the Hitachi TM4000II Plus Scanning Electron Microscope (SEM) and its Scanning Transmission adapter in biological imaging. A variety of specimens, including protozoans (e.g., Volvox and nematodes), bacteria (e.g., Magnetospirillum gryphiswaldense, Bacillus cereus, and Escherichia coli), tissue samples, and blood, were analyzed. While the SEM effectively imaged protozoans and bacteria, its ability to visualize viruses was deemed impractical. Despite claims of magnification up to 100,000x, clarity significantly decreased beyond 5,000x. The transmission adapter proved functional but challenging to operate consistently. The study highlights the microscope's limitations in producing high-clarity, …

Ophidiomyces Ophidiicola And Texas Snakes: A Field To Bench Study Of Ophidiomycosis, Kenlynn L. Volz

Biology Theses

Ophidiomyces ophidiicola (Oo), the primary cause of Ophidiomycosis, is a fungal pathogen recently detected in Texas snakes. Prior to this study, there were major knowledge gaps regarding Oo growth, spread, and suitable environmental conditions. This study filled those gaps using a field to bench approach involving sampling snakes across Texas, in vitro fungal growth, and ecological niche modeling. 103 snakes were sampled across Texas in 2023 and 2024 and six cases of Oo infection were detected. Results of the growth experiment suggest that Oo prefers more stable temperatures and high humidity to a point and that there is a …

Antibiotic-Resistant Gram-Negative Bacteria In A Local Wastewater Treatment Plant In North Georgia, Nou Moua, Lindsay Mccuen, Sarah White, Swapna Bhat, Margi Flood, Jeanelle Morgan

Georgia Journal of Science

Antibiotics are some of the most essential lifesaving drugs currently available to us against infectious diseases. Several pathogens are developing resistance to these drugs and many have become resistant to multiple antibiotics. Such multi-drug resistance is becoming a global issue and has been found in many environments including wastewater treatment plants (WWTPs). In this study, we sampled a local WWTP for antibiotic-resistant bacteria. This WWTP is in North Georgia and runs directly into Lake Lanier, which is the main source of drinking water for the Atlanta area as well as a popular spot for water recreation. We obtained treated and …

Using Origami And Shrinky Dinks To Create Active Learning Activities To Tackle Two Microbiology Concepts: Cell Structure Differences And Operon Regulation, Manuela Tripepi, Hannah M. Schapiro

College of Life Sciences Faculty Papers

This paper presents two low-cost hands-on activities designed to enhance student understanding and address the pedagogical challenges faced by microbiology professors in teaching concepts related to cell structure and gene regulation. In the first activity, we used Shrinky Dinks and Jeopardy-style game questions to explore the differences between prokaryotic and eukaryotic cells. Students have to collect pieces and physically build their cell models. The second activity uses origami organelles sets from Edvotek to illustrate the regulation of gene expression in the lac and trp operons, incorporating mutation scenarios for analysis. The intended audience comprises undergraduate students in microbiology, including biology, …

The Experience Of Homelessness And Its Effects On Gut Eubiosis, Kamerin Villagomez

University Honors Theses

Microorganisms which populate the human gastrointestinal tract (GIT) have a profound effect on overall human health. The relationship between host health and eubiosis, or balance, of the GIT microbiome is symbiotic and can have reciprocal relationships with quality of sleep, quality of diet, stress and mental health, and the experience of pain. These specific aspects of health are unique in populations experiencing homelessness due to the multi-dimensional and complex nature of their lived experience. Very few studies explore populations experiencing homelessness, with even fewer investigating the intersection between this population and the human GIT microbiome. It is important to do …

Investigating The Presence Of Bacterial Phytoplasma Disease In Grasses Of Central Texas And Their Associated Hemiptera, Danielle Rios

Masters Theses (Archived)

No abstract provided.

Manipulation Of Cellular Proliferating Cell Nuclear Antigen (Pcna) During Herpes Simplex Virus Type 1 Infection, Jessica Packard, Jill A. Dembowski

Electronic Theses and Dissertations

Herpes simplex virus type 1 (HSV-1) is a double stranded DNA virus that replicates within the nucleus of host cells. Using accelerated native isolation of proteins on nascent DNA (aniPOND), cellular proteins were found to associate with HSV-1 replication forks. One host factor of interest is proliferating cell nuclear antigen (PCNA), the DNA sliding clamp that tethers DNA polymerases and DNA damage response proteins to replicating cellular DNA. Although HSV-1 encodes its own DNA polymerase processivity factor (UL42), PCNA plays a key role in HSV-1 infection. We used commercially available PCNA inhibitors and short hairpin RNAs (shRNA) to investigate how …

Uvc And Planetary Habitability: Insights From Desert Lichens And Cyanobacteria, Tejinder Singh

UNLV Theses, Dissertations, Professional Papers, and Capstones

An important question in astrobiology is whether life can exist under the levels of UVC radiation found on Archean Earth, Mars, and exoplanets. We investigated this question by studying the UVC survival of colonial cyanobacterium and lichens that grow in harsh desert environments and possess natural sunscreens. We irradiated them nonstop in a desiccated state with a UVC flux closely representing the upper limit on those planets: 55-60 W/m². After irradiation, we rehydrated and assessed their survival using chlorophyll fluorometry and by counting the number of viable colonies that formed on agar plates. All three study organisms survived two to …

Probing The Ecological Functions Of Thermophiles Using Cultivation-Dependent And Cultivation-Independent Techniques, Dengxun Lai

UNLV Theses, Dissertations, Professional Papers, and Capstones

High-temperature geothermal springs are ecosystems that resemble early Earth, offering insights into the origins and early evolution of life. In these unique ecosystems, thermophilic microorganisms thrive. However, our knowledge of thermophiles remains limited. A major challenge is that many thermophiles remain uncultivated. The primary goal of this dissertation was to explore the diversity, metabolism, and ecological functions of thermophiles using cultivation-dependent and cultivation-independent approaches. Chapter 1 provides a broad overview of geothermal spring ecosystems and thermophiles, along with a roadmap of the dissertation. Chapter 2 documents a study on the response of specific thermophiles from Gongxiaoshe (GXS) Hot Spring in …

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 …

Effects Of Vitis Vinifera L. Seed Extract On Short-Term Memory Of Amyloid-Beta-Mediated Neurodegeneration In Transgenic Caenorhabditis Elegans, Elise Patrick

Theses

Alzheimer's disease (AD) is a neurodegenerative condition that is a common cause of dementia and a growing concern worldwide with no effective treatment or cure. Two pathological AD hallmarks include buildup of amyloid beta (Aβ) plaques and neurofibrillary tangles in the brain. Recent attention has turned to exploring natural products and compounds for AD symptom relief and treatment. Vitis vinifera grape seed extract (GSE) contains many beneficial substances. GSE has been tested in several animal models and has shown to improve memory and is even being examined in an AD treatment human clinical trial. In this study, the aim was …

Elucidation Of Potential Antimicrobial Properties Of Chalcones, Caleb Howell

Theses

The rise of antibiotic-resistant bacteria is a growing concern for the medical and biological community. Increased use of antibiotics has led to increased development of bacterial tolerances. This phenomenon, driven by the principles of evolution, has been exacerbated by the improper antibiotic use of these antibiotics. Often, individuals stop taking antibiotics once symptoms subside, mistakenly believing the infection is cured. This practice allows bacteria or fungi to develop resistance.

These antibiotics have been developed from secondary metabolites. While we have many effective antibiotics we are facing new threats. Chalcones are being looked at for their potential in addressing this issue. …

Investigating The Antimicrobial Potential Of Bovine Lactoferrin Against The Neonatal Pathogen, Staphylococcus Capitis, Anna Desmond, Lesley Cotter, Des Field, Fiona O'Halloran

Department of Biological Sciences Publications

Lactoferrin is an antimicrobial glycoprotein that demonstrates a broad-spectrum of activity against a wide variety of clinical pathogens. This study investigated the potential of bovine lactoferrin (bLf) against multidrug resistant Staphylococcus capitis (S. capitis) strains. Growth curve analysis and time-kill curves demonstrated that at 750 µg ml−1 lactoferrin significantly inhibited (50.6%, P < 0.05) the growth of most isolates tested (90%), and this effect was based on a bacteriostatic mechanism. At the same concentration, bLf also significantly inhibited (30%, P < 0.05) biofilm formation in 40% of strains tested. Combinations of bLf with selected antibiotics were assessed for enhanced antimicrobial activity using growth curves. BLf combined with β-lactam antibiotics reduced the growth of S. capitis strains, however, the effects were not significant. BLf displays antimicrobial effects against multidrug resistant S. capitis isolates, but with strain-specific effects.

Characterizing The Quorum Sensing (Qs) System In The Model Eukaryote Chlamydomonas Reinhardtii, Kirstin Donnette Cutshaw

Theses and Dissertations

Group behaviors in microorganisms are often regulated by low-molecular weight molecules that enable them to sense population density, a signaling system known as quorum sensing (QS). QS in prokaryotes has provided insight into the role ‘social’ behaviors play in the bacterial world and refined our models of virulence, bacterial motility, and more. While less common, similar behaviors are observed in certain fungi, primarily yeasts, in which QS controls cell morphology, biofilm production, and other phenotypes. We have recently pursued the potential for QS to be more broadly distributed among unicellular eukaryotes, which could significantly alter our understanding of social behaviors …

Isolation Of Naegleria Lustrarea N. Sp. (Excavata, Discoba, Heterolobosea) From The Feces Of Ambystoma Annulatum (Ringed Salamander) In Northwest Arkansas, Brian M. Becker, Idan Banson, James M. Walker, Anant Deshwal, Matthew W. Brown, Jeffrey D. Silberman

Biological Sciences Faculty Publications and Presentations

The salamander, Ambystoma annulatum, is considered a “species of special concern” in the state of Arkansas, USA, due to its limited geographic range, specialized habitat requirements and low population size. Although metazoan parasites have been documented in this salamander species, neither its native protists nor microbiome have yet been evaluated. This is likely due to the elusive nature and under-sampling of the animal. Here, we initiate the cataloguing of microbial associates with the identification of a new heterlobosean species, Naegleria lustrarea n. sp. (Excavata, Discoba, Heterolobosea), isolated from feces of an adult A. annulatum.

Uses Of Herbal Extracts In Endodontology: A Literature Review, Reem Chamseddine, Roula S. Abiad

BAU Journal - Science and Technology

The use of natural herbal extracts in the field of dentistry, and specifically in endodontology had gained a high popularity in the past few years. The main objective of endodontic treatment is to prevent and eliminate the infection from the root canal, seize the invasion of microorganisms to periradicular tissues and preserve the natural dentition. Studies had shown that some herbs are better alternatives to traditional chemical irrigants or medicaments used in root canal treatment, based on their potential antimicrobial effect, smear layer removal capabilities, tissue dissolution effect, antioxidant, anti-inflammatory and regenerative properties. Aim: The purpose of this literature review …

Dietary Saturated Fatty Acids Modulate Host Innate Immunity, Amy Lorraine Seufert

Dissertations and Theses

Nutrition, cellular metabolism, and inflammatory regulation of the immune system are interconnected, and advancing our understanding of this will greatly improve treatment of metabolic and inflammatory disease. Specifically, dietary saturated fats are becoming increasingly appreciated for their ability to modify innate immune cell function in mammals following absorption into the blood and lymphatic circulation systems. The work herein focuses on the capacity for lipids in the diet to modulate innate immune memory. My thesis first broadly outlines fundamental background, including: the evolution of human nutrition, the discovery of innate immune memory, and key topics that reoccur throughout the text surrounding …

Metagenomic Analysis Of Antarctic Microbial Communities, David Michael Robinson

Biology ETDs

The research presented in this dissertation focuses on microbial roles in biogeochemical cycling in Antarctic aquatic environments. The major objective of my research was to examine the impact of biotic and abiotic pressures on nutrient cycling in microbially dominated systems. I used three perennially ice covered lakes in the McMurdo Dry Valleys (MDVs) along with subglacial lakes Whillans and Mercer as natural case studies. The MDVs are located in Victoria Land, East Antarctica and have been studied since 1993 as part of the McMurdo Long Term Ecological Research Project. Viruses in the MDVs were shown to be seasonally abundant and …

Prochlorococcus Death By A Ubiquitous Zooplankton Filter Feeder, Avery Harman

University Honors Theses

Prochlorococcus is a globally abundant cyanobacterium that can help reveal the ecology of microorganisms in the ocean. Specifically, mortality by zooplankton such as appendicularians is globally important and Prochlorococcus can help reveal some of the choices made around feeding for this ubiquitous filter feeder. Two ecotypes of Prochlorococcus were introduced to appendicularians to determine if appendicularian feed selectively between these ecotypes. Further, a single ecotype of Prochlorococcus was fed to appendicularians over a variety of life stages to determine if retention rate changed with appendicularian life stage. My results reveal that there is no significant selection between the two Prochlorococcus …

Tetr Family Regulator, Farr, Influences Rot-Mediated Control Of Virulence Factor Expression In Staphylococcus Aureus, Julia C. Schumacher

USF Tampa Graduate Theses and Dissertations

Point-mutation variants of the TetR family regulator, FarR, have emerged across Staphylococcus aureus sequence types as conferring antibiotic and fatty acid resistance, particularly in Hospital-Associated Methicillin Resistant S. aureus (HA-MRSA) strains. FarR also exhibits an additional largely uncharacterized relationship to virulence factor production, seemingly through the global repressor of toxins—Rot, which functions to regulate S. aureus’ ability to colonize and persist in the host via a complex cascade of signaling. While Rot protein is post-transcriptionally regulated by the highly characterized Agr system, there is little known about its transcriptional regulation. Herein, we explored these dynamics by initially characterizing virulence phenotypes …

The Anticancer Activity Of A Novel 8-Hydroxyquinoline Derivatives Against 5-Fluorouracil Resistant Colorectal Cancer Cells, Mazoun Talal Al Azzani

Theses

Cancer is a global health crisis for which 20 million new cases were diagnosed in 2022 alone, with 9.3 million cancer-related deaths. Nearly 900,000 deaths were due to colorectal cancer (CRC), which is the third leading cause of cancer related mortality. In the United Arab Emirates, 550 new cases of CRC were reported in 2022. A major clinical challenge with CRC treatment is the development of resistance to 5-fluorouracil (5FU)-based chemotherapy regimens, which are the standard treatment for CRC. In the present study, the anticancer activity of two novel 8-hydroxyquinoline (8-HQ) derivatives AS45 and AS47 was examined against 5FU-sensitive (HCT116) …