Microbiology Commons^™

Characterization Of The Human Thnatomicrobiome By Decomposition Stage Through Bioinformatic And Meta Data Analysis, Ashton C. Laughlin

Biology Theses

Estimating the postmortem interval (PMI) is one of the most crucial factors in forensic death investigations. Recent advances in forensic microbiology have led to increased interest in using the study of the human postmortem microbiome, or “thanatomicrobiome,” to improve PMI estimates. In addition to current PMI estimation techniques, microbial community succession could serve as a valuable tool in estimating PMI. Further research is needed to develop a comprehensive understanding of the human postmortem microbiome. The purpose of this study is to contribute to the expansion of this tool by reviewing the current literature and analyzing previously published data using the …

Microbial Community Structure In Global Soils, Matthew Jabro

CMC Senior Theses

Soil harbors the most diverse microbial communities on Earth, yet whether predictable community types exist across biomes and whether taxonomic composition encodes habitat of origin remain open questions at global scale. This thesis addresses both questions by applying unsupervised clustering and supervised classification to transformed 16S ribosomal RNA (rRNA) amplicon profiles from two independent datasets: the global topsoil survey of Bahram et al. (193 samples) and the Earth Microbiome Project (EMP) soil subset of Thompson et al. (2,209 samples). Application of a sample clustering method based on a mixture of Gaussian Graphical Models (MixGGM) identified 19 clusters in the topsoil …

From Theory To Ecosystems: Exploring Biodiversity And Ecosystem-Function In Pitcher Plant (Darlingtonia Californica) Microbial Communities, Gavin Sutter

Cal Poly Humboldt theses and projects

The relationship between biodiversity and ecosystem-function (BEF) has been a central focus of ecological research for the last three decades, yet the role of space in shaping BEF relationships remains relatively unknown. Research has shown that community diversity and composition can strongly influence productivity, nutrient cycling, and decomposition, but much of this work treats communities as spatially isolated, leaving open how dispersal and other spatial processes shape BEF at broader scales. To begin addressing this gap, I used microbial communities inhabiting Darlingtonia californica pitcher plant leaves to evaluate how spatial organization and successional change shape biodiversity and ecosystem-functioning. I quantified …

Characterizing Gut Microbial Communities And Symbiont-Mediated Detoxification In Herbivorous Insects, Rachel C. Vargas

Biology Dissertations

Insect gut bacteria are vital contributors to host physiology, yet the broader prevalence and fitness implications of symbiont-mediated detoxification remain poorly understood. This thesis investigates these dynamics across three research chapters. Chapter 1 uses 16S rRNA sequencing to characterize how grasshopper gut microbial communities vary across species, dietary breadths, and gastrointestinal segments. Chapter 2 evaluates the detoxification capacity of over 150 bacterial isolates from diverse herbivores against the plant allelochemicals phenethyl isothiocyanate, rutin, and chlorogenic acid to determine if host dietary specialization predicts microbial metabolic ability. Finally, Chapter 3 employs fitness bioassays to test whether inoculating generalist herbivores with detoxifying …

Development Of A Semi-Mechanistic Pharmacokinetic-Pharmacodynamic Model For Beta-Lactam Antibiotic Combination Against Enterococcus Faecalis Based On Time-Kill Assays To Predict Drug Disposition And Guide Dosing Strategy In A Severe Renal Impairment Population, Ruhma Zia Khan

Selected Full-Text Dissertations 2020-

Bacterial resistance to antibiotics continues to be a global health problem, limiting antibacterial therapy against infective endocarditis caused by Enterococcus faecalis. To overcome increasing resistance, dual beta-lactam therapy has been advocated as an alternative regimen for treatment – the synergistic activity against E. faecalis demonstrated to be effective. Currently, ampicillin plus ceftriaxone is the standard of care, but the practical application of this therapy is limited by ampicillin’s poor stability in solution at room temperature. A synergistic combination of penicillin plus ceftriaxone shows promise due to penicillin’s superior stability at ambient temperature, but ceftriaxone’s potential to cause hepatoxicity further limits …

The Rna-Binding Protein Pumilio Limits Polymodal Noiception In Drosophila Larvae, Sara Palega, Hannah Davenport, Rebeccah K. Stewart, Jessica Horton, Andrew Bellemer

Microbiology & Molecular Cell Biology Faculty Publications

Nociception is the process by which the nervous system detects and processes information about potentially harmful environmental stimuli to generate behavioral and physiological responses. The process of nociception undergoes plasticity in response to injury, inflammation, and infection to shape the sensitivity of nociceptive circuits and the behavioral responses they control. We are increasingly aware that post-transcriptional regulation of gene expression shapes the sensitivity and plasticity of nociceptive sensory neurons and nociceptive behavior. In Drosophila, the Pumilio RNA-binding protein interacts with diverse target mRNAs to regulate their abundance and translation in a wide range of contexts including the establishment of …

Use Of Enterococcus Faecalis And Cetylpyridinium Chloride In Altering Canine Mouth Microbiome, Quigley D. Espinola, Scarlet Renner, Curtis Cline, Sofia Lopez-Orenday, Alex Yasumatsu

Humboldt Journal of Microbiology

Like most mammals, canines have copious amounts of bacteria in their oral cavity. While some of these bacteria are beneficial and even necessary to their health, overgrowth of harmful bacterial strains can lead to plaque buildup and gum disease. To combat plaque and bacteria, several products are marketed towards canines. In this study, we aim to explore how the microbiome of the canine mouth is affected by a potential probiotic, Enterococcus faecalis, and an antimicrobial water additive found in dog mouthwash products, Cetylpyridinium chloride monohydrate (CCM). We hypothesized that both would be successful in their ability to decrease harmful bacteria. …

Exploring The Link Between Soil Microbes, And Land Use Through A One Health Lens, Yaw A. Antwi

Master's Theses or Doctor of Nursing Practice

The diversity of microbes within the soil plays an essential role in soil ecosystem

functioning. However, these microbes may also serve as environmental reservoirs for antibiotic resistance genes. The study examined the diversity of bacteria that are found in soil across Rural/Agricultural and Rural/Nonagricultural landscapes within some selected counties in Kansas and its associated antibiotic resistance genes taxa. A total of twenty-four soil samples was collected and analyzed using 16S rRNA gene amplicon sequencing which targeted the V3-V4 regions. Statistical analysis revealed that the alpha diversity metrics (Chao1 richness and Shannon evenness) showed no significant difference in microbial structure (p=0.693, …

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 …

The Coral Microbiome Under Climate Change: Shifting Symbiotic Interactions, Katherine E. Parker, Kate M. Quigley

Biological Sciences Faculty Publications

Host–microbe symbioses are central to organismal health, yet these complex partnerships are often strongly shaped by the environment. Climate change is increasingly altering environmental conditions, disrupting the balance of host–microbe interactions and pushing them along a continuum from mutualism (both partners benefit) toward parasitism (one partner gains at the other’s expense). Reef-building corals provide a clear example of this vulnerability, as the coral holobiont, an ecological unit comprising diverse photosynthetic algal symbionts (Symbiodiniaceae) and other microbial partners, depends largely on these mutualistic interactions for nutrition, immunity, and stress tolerance. Increasingly, evidence suggests that under heat stress, the algal symbionts retain …

The Effect Of The Affordable Care Act Medicaid Expansion On The Risk Of Hospital Closure And Adolescent Hpv Immunization In Rural Counties, Juliette Des Rosiers

Scripps Senior Theses

From 2005 to 2025, over 200 rural hospitals shut their doors, often citing increased operational costs, staffing shortages, low patient volume, regulatory barriers, financial challenges exacerbated by the COVID-19 pandemic, and uncompensated care as common contributors to the closures. Rural patients are often referred by their primary care physician to a hospital for regular immunizations, since smaller clinics have less capacity to provide immunizations due to a shortage of pediatricians and limited vaccine stock. A crucial vaccine that is not required by schools and underutilized in rural areas is that against human papillomavirus (HPV), a virus that infects cutaneous and …

Lead Biosorption By Oceanobacillus Profundus Kbz 3-2: Strategies For Bioremediation Systems In Kabwe, Danielle S. Desmarteau

Scripps Senior Theses

Lead contamination remains a significant global public health concern, particularly in Kabwe, Zambia, the site of a former lead mining operation. Bioremediation, which utilizes biological materials and processes to remove environmental contaminants, represents a promising approach for addressing lead pollution. However, the development of effective bioremediation systems requires a detailed understanding of the mechanisms underlying metal removal and the feasibility of implementation in low-resource settings. Oceanobacillus profundus KBZ 3-2, a bacterium isolated from Kabwe mine waste, has demonstrated the ability to remove lead from aqueous environments. This study proposes to investigate the mechanism of lead biosorption by this organism, …

Pipeline Corrosion And Relevant Microbial Influence, Renee E. Bamberger

Williams Honors College, Honors Research Projects

This study investigated the role of microbial activity and oxygen availability in the corrosion of carbon steel pipelines with a focus on microbially influenced corrosion (MIC). Sediment collected from Old Woman Creek, Ohio, was used to simulate natural soil conditions, and carbon steel coupons were incubated under four treatments: nonsterile oxic, nonsterile anoxic, autoclaved oxic, and autoclaved anoxic over 85 days. Corrosion was assessed through mass loss measurements and the analysis of pH, sulfate, chloride, and dissolved iron concentrations. The greatest mass loss was observed in autoclaved oxic conditions, contrary to the initial hypothesis that microbial activity would greatly enhance …

Evaluation Of Mycoplasma Genitalium Positivity And Co-Infection With Chlamydia Trachomatis And/Or Neisseria Gonorrhoeae At Various Care Sites Across The United States, Rebecca Lillis, Rodney Arcenas, Christy M. Boraas, Steven E. Chavoustie, Lashonda Crane, Nicole D'Empaire, Aaron C. Ermel, Glenn Harnett, Federico Hinestrosa, Stacey House, Joseph Miller, Anthony Mills, Ronald Poblete, Stephen Young, Barbara Van Der Pol

School of Medicine Faculty Publications

OBJECTIVES: We evaluated Mycoplasma genitalium (MG) positivity and co-infection with Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG), based on results from a trial assessing clinical performance of the Cobas® Liat CT/NG/MG point-of-care test. METHODS: A prospective, US, multicenter, noninterventional study assessed MG positivity in prospective urine samples (male) and clinician-collected vaginal swabs (female) from symptomatic/asymptomatic patients aged ≥14 years attending various clinical settings. Participants were designated positive or negative for MG, CT, and NG based on combined results from three US Food and Drug Administration-approved assays and one laboratory-developed test. MG co-infection with CT and/or NG was assessed. RESULTS: Among …

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 …

Investigating The Interaction Of Gram-Positive Lactobacillus Species With Mucin In The Context Of Barrett's Esophagus, Ritisha Suresh

Honors Undergraduate Theses

Gastroesophageal Reflux Disease (GERD) can progress to the precancerous Barrett’s Esophagus (BE) condition, in which the normal esophageal squamous epithelium is replaced with a columnar epithelium containing goblet cells. Mucins, sticky substances, are secreted in response to bile acid exposure during reflux episodes to protect the esophageal epithelium. Goblet cells secrete these mucins, which can also scaffold microbial colonization. Probiotic Lactobacillus bacteria can use glycosidase enzymes to process mucin and metabolize them into their component sugars (glycans). This project aims to identify the role of the Lactobacillus-mucin interaction in BE, as glycan availability could confer an advantage to Lactobacillus …

Coordinating The Layers: Regulation Of Peptidoglycan Synthesis And Cell Wall Assembly In Mycobacterium Smegmatis By Murj And Pgfa, Karen Emmanuella Samaga-De-Tembiwa

Biology Dissertations

The mycobacterial cell envelope consists of three covalently linked layers whose synthesis must be coordinated to maintain structural integrity during polar growth. While the biosynthetic enzymes for each layer are well characterized, the molecular mechanisms that coordinate synthesis across layers have remained poorly understood. This thesis investigates two essential transmembrane proteins, PgfA and MurJ, that regulate peptidoglycan metabolism in Mycobacterium smegmatis and provide new insight into how mycobacteria synchronize cell wall assembly.

We present evidence that PgfA functions as a bifunctional regulator that links peptidoglycan metabolism to the availability of trehalose monomycolate (TMM), a key mycolic acid precursor. Through epistasis …

Characterizing The Human Metapneumovirus Matrix Protein And Its Role In Infection, Chase J. Heim

Theses and Dissertations--Molecular and Cellular Biochemistry

Human metapneumovirus (HMPV) causes severe respiratory tract infections in all cohorts, but especially in vulnerable groups such as children, older adults, and the immunocompromised. The matrix (M) protein of HMPV, like the M proteins of other members of the Mononegavirales order, is involved in virus assembly and budding. However, other functions of the HMPV M protein have yet to be elucidated. To investigate these various functions of the M protein, we used a peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO) antisense agent designed to block translation of the M gene to reduce M expression during infection. Treatment with varying concentrations of an …

Environmental Monitoring In Shallow Lakes: Public Health Threats In Urban Waters, Kyleigh E. Johnson

Theses and Dissertations

Lakes are an integral part of urban and suburban communities, providing ecological, recreational, and public health benefits. Many of these lakes are located in densely populated areas and are subject to urban influences on water quality. Algal toxins and Escherichia coli are two common recreational concerns. Algal toxins come from harmful algal blooms that are influenced by nutrient availability and temperature, while bacteria are often introduced through run-off and animal waste. Sampling every 3-4 weeks from May-October 2025 allowed for the assessment of seasonal patterns and site-specific differences across nine lakes in the Richmond area. The highest bacterial concentrations appeared …

Depemokimab: A Twice Yearly Anti-Il 5 Biologic For Chronic Rhinosinusitis With Nasal Polyps (Crswnp) - A Narrative Review, Marn Joon Park, Joseph K. Han, Kent K. Lam

Department of Otolaryngology (ENT) Faculty Publications

Depemokimab is a monoclonal antibody that targets interleukin-5 with enhanced binding affinity and an extended terminal elimination half‑life of 6-8 weeks. The unique pharmacodynamic features of depemokimab enable sustained suppression of type 2 inflammation with twice‑yearly subcutaneous dosing. This narrative review provides details of depemokimab's molecular profile, pharmacokinetics, and pharmacodynamics and results regarding the clinical efficacy and safety of depemokimab from recently published Phase 3 clinical trials for the treatment of chronic rhinosinusitis with nasal polyposis (CRSwNP). In 528 severe adult CRSwNP patients (ANCHOR‑1/‑2 trials), depemokimab achieved Δ total endoscopic nasal polyp score by -0.70 (p <  .001) and Δ nasal obstruction verbal response scale by -0.24 (p = .003) at week 52, compared to placebo. Twice‑yearly 100 mg depemokimab provides durable eosinophil suppression and with a safety profile comparable to placebo in Phase 3 trials for CRSwNP. Future work should refine biomarkers and assess comparative cost‑effectiveness and long‑term adherence, safety, and effectiveness.

The Ecological Consequences Of Horizontal Transmission Of Symbionts, Bibek Singh Parajuli

Biology Dissertations

Most multicellular organisms depend on their microbial symbionts for various functions, such as digestion, nutrient supplementation, pesticide degradation, and defense. While many insects acquire their symbionts vertically from their parents, thousands of species of true bugs (Hemiptera) across different families acquire their microbial symbiont, Caballeronia, from the environment each generation. Acquiring symbionts from the environment (horizontal transmission) has various ecological consequences for the host. In this study, I used the bug-Caballeronia model 1) to understand whether the free-living symbionts benefit from association with multicellular hosts, 2) to evaluate whether host specialization on symbiont strains varies across taxonomic levels, …

Effects Of Fermented Soybean Products On The Human Gut Microbiome, Microbial Metabolism, And Host Physiology, Shannon Moncier

Biology Dissertations

Fermented soybean products (FSPs) contain soybean-derived substrates, fermentation-associated microorganisms, and bioactive compounds that may interact with the human gut microbiome and host physiology. However, despite the growing interest in FSPs, longitudinal human studies specifically evaluating traditional Korean-FSPs (K-FSPs), particularly among United States-based populations, remain limited. The objective of this work was to evaluate the effects of three K-FSPs, including Cheonggukjang, Gochujang, and Doenjang, on host physiological responses, gut microbial community structure, predicted microbial functional potential, and fecal butyrate responses in healthy adults. Three independent dietary intervention cohorts were conducted using FSP formulations produced either by traditional artisan methods (Product A) …

Remediation Impacts Metal Concentrations And Metal Tolerant Bacteria In Soils Of The Missouri Tri-State Mining District, Ophelia R. Pettington

Graduate Theses/Dissertations

After over 100 years of Zn and Pb mining in the Tri-State mining district (TSMD), former mines continue to be sources of metals. Metal contaminated soils can be remediated using plant-microbe interactions. Plants manipulate their microbiome and recruit microbes to increase metal tolerance. Remediating bacteria are site-specific and identifying native microbes can accelerate remediation efforts. Studies relating microbes and metal concentrations in remediated areas in the TSMD are scarce. I collected root and bulk zone soils associated with Andropogon virginicus from remediated and non-remediated sites in Webb City, MO. I used 16S rRNA gene amplicon sequencing to evaluate the bacterial …

The Geminivirus Al2 Protein Interacts With Host Proteins Involved In The Plant Antiviral Response, Pheobean Atieno Odongo

Graduate Research Theses & Dissertations

Geminiviruses are economically important plant DNA viruses infecting a broad range of plant species and causing devastating crop diseases, resulting in up to 100% crop loss. As a result of these heavy losses on food and cash crops, these viruses represent a new threat to global food security and sustainability. In this research, I use Tomato golden mosaic virus (TGMV) to study host-virus relationships with an overall goal of developing sustainable and eco-friendly crop resistance. TGMV belongs to the Geminivirus subgroup, Begomovirus, that is characterized by a split genome consisting of two single-stranded circular DNAs. The TGMV genome encodes proteins …

Management-Driven Shifts In The Bison Fecal Microbiome And Its Relationship To Stec Prevalence, Ritesh Ray

Graduate Research Theses & Dissertations

Contamination of meat samples from pathogens such as Shiga toxin-producing E. coli (STEC), especially in ruminants, is an ever-growing issue for the safety of global meat production. Recent studies have reported STEC in the livestock and food industry with a limited focus on wildlife. Although cattle serve as the primary reservoir for STEC, American bison (Bison bison bison) is the largest ruminant inhabiting North America, sharing similar genetics, and grazing habits, making them an ideal alternative STEC reservoir. Re-introduction for prairie conservation and meat farming has brought bison herds closer to anthropic environments than before. Recently bison meat has become …

Exploring The Application Of Wastewater Monitoring To Determine The Prevalence And Diversity Of Influenza On The Campus Of West Virginia University, Lakyn Renee Sanders

Graduate Theses, Dissertations, and Problem Reports (ETD)

Influenza viruses (IV) affect populations globally, with the World Health Organization (WHO) estimating that IV are responsible for an estimated 3-5 million infections and 290,000 – 650,000 deaths annually^1–3. More specifically, the 2019-2020 IV season is associated with an estimated 38 million illnesses and 22,000 deaths in the United States alone⁴. IV are rapidly spread between individuals through direct contact with infected individuals, contaminated surfaces, or aerosolized virus particles². Traditional IV infection monitoring relies on clinical screening of patients presenting influenza-like symptoms, commonly through the use of multi-target panel tests such as the BioFire …

The Role Of Temperature And Carbon Source In Nutrient Acquisition For Peptidoglycan Synthesis In A Gfp-Expressing Borreliella Burgdorferi, Barrett-Anne Conner Briggs

Graduate Theses, Dissertations, and Problem Reports (ETD)

Lyme disease is the most common vector-borne disease in the United States with an estimated yearly incidence rate of more than 300,000 cases. Borreliella burgdorferi, the etiological agent of Lyme disease, is transmitted by the bite of an infected Ixodes scapularis tick and can cause debilitating pathologies affecting numerous body systems. Symptoms include fever, fatigue, joint pain, and a characteristic bull’s eye rash (erythema migrans) at the site of the tick bite. The timely and appropriate use of antibiotics effectively treats early Lyme disease; however, uncomfortable side effects reduce treatment compliance. If left untreated, long-term complications can arise including facial …

Exploring The Interplay Of Operational Conditions, Microbial Communities, And Water Quality In Drinking Water Ozone-Biofiltration, Kara Yvonne Cunningham

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ensuring reliable access to safe drinking water is a growing global challenge as water utilities face variable source water quality driven by population growth, land‑use change, and climate change impacts. To address these challenges, utilities are implementing advanced treatment technologies designed to improve reliability under variable source water conditions. Ozone-biofiltration has emerged as a treatment approach that can reduce a wide range of natural and anthropogenic contaminants. However, despite its increased use, there is limited insight into the biological processes shaping filter function or how they respond to operational and environmental changes. Advances in molecular microbiology and high-throughput sequencing now …

Plant Invasion Patterns In Understory And Soil Microbial Communities Of North Central West Virginia Mixed Hardwood Forests, Isabelle Marie Uganski

Graduate Theses, Dissertations, and Problem Reports (ETD)

Invasive plants alter forest ecosystems by reducing species richness, habitat heterogeneity, and nutrient cycling as they rapidly displace native plants. Invasive plant composition can influence soil health through altering soil microbial associations and communities. By studying the mechanisms in which invasives alter above- and below-ground communities, we can better understand whole-ecosystem impacts and inform management decisions. This study examined the relationships between co-occurring invasion on above and belowground communities of mixed hardwood forests of north central West Virginia. Despite distinctive associations with aboveground characteristics (native diversity, native tree regeneration, and leaf litter density) we detected limited changes to soil microbial …

Role Of The Osaa Transcription Factor Gene In Development, Secondary Metabolism And Virulence In The Mycotoxigenic Fungus Aspergillus Flavus, Farzana Ehetasum Hossain

Graduate Research Theses & Dissertations

Aspergillus flavus colonizes oil-seed crops, contaminating them with aflatoxins; highly carcinogenic mycotoxins that cause severe health and economic losses. Genetic studies may reveal new targets for effective control strategies. Here, we characterized a putative WOPR transcription factor gene, osaA, in A. flavus. Our results revealed that osaA regulates conidiation and sclerotial formation. Importantly, deletion of osaA reduces aflatoxin B1 production, while, unexpectedly, transcriptome analysis indicated upregulation of aflatoxin biosynthetic genes, suggesting post-transcriptional or cofactor-mediated regulation. Cyclopiazonic acid production also decreased in the absence of osaA. In addition, the osaA mutant exhibited upregulation of genes in the imizoquin and aspirochlorine clusters. …