Microbiology Commons^™

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 …

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 …

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 …

Low-Dose Metformin Requires Brain Rap1 For Its Antidiabetic Action, Hsiao-Yun Lin, Weisheng Lu, Yanlin He, Yukiko Fu, Kentaro Kaneko, Peimeng Huang, Ana B De La Puente-Gomez, Chunmei Wang, Yongjie Yang, Feng Li, Yong Xu, Makoto Fukuda

Faculty, Staff and Students Publications

Metformin is the most commonly prescribed antidiabetes drug, yet its precise mechanism of action remains controversial. Previous studies have suggested that metformin acts peripherally by reducing hepatic glucose output and altering gut functions. Here, we report a neural mechanism via the small guanosine triphosphatase Ras-related protein 1 (Rap1). Mice with forebrain-specific Rap1 knockout exhibited resistance to the antidiabetic effects of low-dose metformin while remaining sensitive to other antidiabetic agents. Centrally administered metformin inhibited brain Rap1 and reduced hyperglycemia. Conversely, forced activation of brain Rap1 increased glycemia and abolished the glycemic effect of metformin. Metformin activated a specific subset of neurons …

A Toi Rna Editing In Three Members Of The Microbotryum Violaceum Fungal Complext And Characterization Of Adar Genes Of Microbotryum Superbum., Shikhi Baruri

Electronic Theses and Dissertations

A-to-I RNA editing is a process that occurs post-transcriptionally. Through this process, adenosine (A) is replaced by inosine (I) in RNAs by adenosine deaminase enzymes that act on the single-stranded RNA. These enzymes, also known as ADARs, act on RNA. The translation and splicing mechanisms subsequently interpret inosine as guanosine (G), which effectively alters genetic information. This kind of RNA alteration can cause both nonsynonymous and synonymous changes in codon, which may have an impact on protein function. A group of over 89 basidiomycete fungal species known as the Microbotryum violaceum complex infects a similarly large group of plant host …

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 …

Nerve-To-Cancer Transfer Of Mitochondria During Cancer Metastasis, Gregory Hoover, Shila Gilbert, Olivia Curley, Clémence Obellianne, Mike T Lin, William Hixson, Terry W Pierce, Joel F Andrews, Mikhail F Alexeyev, Yi Ding, Ping Bu, Fariba Behbod, Daniel Medina, Jeffrey T Chang, Gustavo Ayala, Simon Grelet

Faculty, Staff and Students Publications

The nervous system has a pivotal role in cancer biology, and pathological investigations have linked intratumoural nerve density to metastasis1. However, the precise impact of cancer-associated neurons and the communication channels at the nerve–cancer interface remain poorly understood. Previous cancer denervation models in rodents and humans have highlighted robust cancer dependency on nerves, but the underlying mechanisms that drive nerve-mediated cancer aggressivity remain unknown2,3. Here we show that cancer-associated neurons enhance cancer metabolic plasticity by transferring mitochondria to cancer cells. Breast cancer denervation and nerve–cancer coculture models confirmed that neurons significantly improve tumour energetics. …

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). …

Single-Cell Transcriptomics Reveals Biomarker Heterogeneity Linked To Cdk4/6 Inhibitor Resistance In Breast Cancer Cell Lines, Ilenia Migliaccio, Martina Bonechi, Dario Romagnoli, Giulia Boccalini, Francesca Galardi, Cristina Guarducci, Agostina Nardone, Rachel Schiff, Laura Biganzoli, Luca Malorni, Matteo Benelli

Faculty, Staff and Students Publications

Cyclin dependent kinases 4 and 6 inhibitors have brought great improvements in the treatment of luminal breast cancer, but resistance is a major clinical hurdle. Multiple biomarkers of resistance have been proposed, but none is currently utilized in clinical practice. By performing single-cell RNA sequencing of seven palbociclib-naïve luminal breast cancer cell lines and palbociclib-resistant derivatives, we show that established biomarkers and pathways related to CDK4/6i resistance present marked intra- and inter- cell-line heterogeneity. Transcriptional features of resistance could be already observed in naïve cells correlating with levels of sensitivity (IC50) to palbociclib. Resistant derivatives showed transcriptional clusters that significantly …

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 …

Phosphoglycerate Mutase Regulates Treg Differentiation Through Control Of Serine Synthesis And One-Carbon Metabolism, Wesley H Godfrey, Judy J Lee, Shruthi Shanmukha, Kaho Cho, Xiaojing Deng, Chandra Shekar R Ambati, Vasanta Putluri, Abu Hena Mostafa Kamal, Paul M Kim, Nagireddy Putluri, Michael D Kornberg

Faculty, Staff and Students Publications

The differentiation and suppressive functions of regulatory CD4 T cells (Tregs) are supported by a broad array of metabolic changes, providing potential therapeutic targets for immune modulation. In this study, we focused on the regulatory role of glycolytic enzymes in Tregs and identified phosphoglycerate mutase (PGAM) as being differentially overexpressed in Tregs and associated with a highly suppressive phenotype. Pharmacologic or genetic inhibition of PGAM reduced Treg differentiation and suppressive function while reciprocally inducing markers of a pro-inflammatory, T helper 17 (Th17)-like state. The regulatory role of PGAM was dependent on the contribution of 3-phosphoglycerate (3 PG), the PGAM substrate, …

Dietary Lipids Induce Ppard And Bcl6 To Repress Macrophage Il-23 Induction After Intestinal Injury And Lps Exposure, Ashleigh M Gil, Daniel F Zegarra-Ruiz, Wan-Jung Wu, Kendra Norwood, Adrien Assie, Buck S Samuel, Angela M Major, Gretchen E Diehl, Andrea A Hill Mcalester

Faculty, Staff and Students Publications

Unresolved tissue damage is a common feature of Inflammatory Bowel Disease (IBD) that facilitates disease progression. Here, we showed that high animal fat diets (HFD), an environmental risk factor associated with IBD pathogenesis, suppress intestinal macrophage production of critical tissue repair responses after damage. This includes reduced IL-23 production, which drives downstream production of IL-22, which is needed for barrier repair. Indicating that dietary lipids interfere with responses to microbial molecules needed to induce barrier protective functions, we found oleic acid could directly suppress macrophage Il23a induction after lipopolysaccharide (LPS) treatment. Deleting the lipid transporter CD36 on macrophages restored the …

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 …

Mouse Metastable Epialleles Are Extremely Rare, Chathura J Gunasekara, Uditha Maduranga, Taylor Zhang, Jonathan N Wells, Maria S Baker, Eleonora Laritsky, Yumei Li, Cristian Coarfa, Yi Zhu, Robert A Waterland

Faculty, Staff and Students Publications

Metastable epialleles (MEs) are genomic loci at which epigenetic marks are established stochastically during early embryonic development and maintained during subsequent differentiation and throughout life, leading to stable epigenetic and phenotypic variation among genetically identical individuals. Although MEs were first described in mice over 20 years ago, the extent of epigenetic metastability in the mouse genome remains unknown. We present the first unbiased genome-wide screen for MEs in mice. Using deep whole-genome bisulfite sequencing across tissues derived from the three embryonic germ layers in isogenic C57BL/6J mice, we identified only 29 MEs, precisely localizing them and documenting their rarity. Consistent …

Altered Patterning Of Neural Activity In A Neuropathology, Clarissa Hoffman, Jingheng Cheng, Rodrigo Morales, Daoyun Ji, Yuri Dabaghian

Faculty, Staff and Students Publications

The dynamics of neural circuits and their role in mediating cellular and organismal phenomena remain poorly understood, despite numerous efforts to dissect these processes through precise instantaneous measurements or longer-time averages and approximations. We use an alternative approach: we investigate these dynamics at the system's mesoscale by analyzing spike trains and waveforms. These extended activity patterns carry robust, tractable information, are highly responsive to physiological specifics, and enable detailed tracking of circuit behavior. In particular, this methodology allows for characterizing the functionality of tau-pathology-afflicted hippocampal circuits and identifying circuit-level abnormalities that are missed by through traditional analyses. In healthy mice, …

Exogenous Arginine Differentially Regulates Inflammatory Cytokine And Inducible Nitric Oxide Synthase Expression In Macrophages, Kelsey Stayer, Saliha Pathan, Aalekhya Biswas, Huiqiao Li, Yi Zhu, Fong Wilson Lam, Juan Marini, Sundararajah Thevananther

Faculty, Staff and Students Publications

Immune dysfunction and late mortality from multiorgan failure are hallmarks of severe sepsis. Arginine, a semi-essential amino acid important for protein synthesis, immune response, and circulatory regulation, is deficient in sepsis. However, arginine supplementation in sepsis remains controversial due to the potential to upregulate inducible nitric oxide synthase (iNOS)-mediated excessive nitric oxide (NO) generation in macrophages, leading to vasodilation and hemodynamic catastrophe. Citrulline supplementation has been considered an alternative to replenishing arginine via de novo synthesis, orchestrated by argininosuccinate synthase 1 (ASS1) and argininosuccinate lyase (ASL). However, the functional relevance of the ASS1-ASL pathway in macrophages after endotoxin stimulation is …

Oral Dosing Of The Nucleoside Analog Obeldesivir Is Efficacious Against Rsv Infection In African Green Monkeys, Jared Pitts, J Lizbeth Reyes Zamora, Savrina Manhas, Thomas Aeschbacher, Josolyn Chan, Vincent Cutillas, Varsha Nair, Nicholas C Riola, Arya Vijjapurapu, Meghan S Vermillion, Stacey Eng, Christopher Richards, Dong Han, Jason K Perry, Subhra Chaudhuri, Szu-Wen Liu, Clarissa Martinez, Nadine Peinovich, Kai-Hui Sun, Arthur Cai, Ross Martin, Jasmine Moshiri, Charlotte Hedskog, Darius Babusis, Dustin S Siegel, Rao Kalla, Vasanthi Avadhanula, Pedro A Piedra, Kim Stobbelaar, Peter L Delputte, Caleb Marceau, Roberto Mateo, Evguenia Maiorova, Hongmei Mo, Raju Subramanian, Richard L Mackman, Tomas Cihlar, Simon P Fletcher, John P Bilello

Faculty, Staff and Students Publications

Respiratory syncytial virus (RSV) is a significant cause of morbidity and mortality in high-risk populations. Although prophylactic options are available, there are no effective oral therapeutics for RSV infection. Obeldesivir (ODV) is an orally bioavailable prodrug of the nucleoside analog GS-441524, which is converted intracellularly to its active nucleoside triphosphate and inhibits the RSV RNA polymerase. Here we report the potent antiviral activity of ODV against geographically and temporally diverse RSV A and B clinical isolates (EC50: 0.20–0.66 μM). Resistance selection studies with ODV and GS-441524 against RSV identify a single amino acid substitution, I777L, in the L polymerase with …

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 …

Single-Cell Profiling Of Bone Metastasis Ecosystems From Multiple Cancer Types Reveals Convergent And Divergent Mechanisms Of Bone Colonization, Fengshuo Liu, Yunfeng Ding, Zhan Xu, Xiaoxin Hao, Tianhong Pan, George Miles, Siyue Wang, Yi-Hsuan Wu, Jun Liu, Igor L Bado, Weijie Zhang, Ling Wu, Yang Gao, Liqun Yu, David G Edwards, Hilda L Chan, Sergio Aguirre, Michael Warren Dieffenbach, Elina Chen, Yichao Shen, Dane Hoffman, Luis Becerra Dominguez, Charlotte Helena Rivas, Xiang Chen, Hai Wang, Zbigniew Gugala, Robert L Satcher, Xiang H-F Zhang

Faculty, Staff and Students Publications

Bone is a common site for metastasis of solid cancers. The diversity of histological and molecular characteristics of bone metastases (BMs) remains poorly studied. Here, we performed single-cell RNA sequencing on 42 BMs from eight cancer types, identifying three distinct ecosystem archetypes, each characterized by an enrichment of specific immune cells: macrophages/osteoclasts, regulatory/exhausted T cells, or monocytes. We validated these archetypes by immunostaining on tissue sections and bioinformatic analysis of bulk RNA sequencing/microarray data from 158 BMs across more than 10 cancer types. Interestingly, we found only a modest correlation between the BM archetypes and the tissues of origin; BMs …