Microbiology Commons^™

Investigation Of Biofilm Formation And Osmotic Stress Tolerance Of Nonmotile E. Coli Mg1655 In Simulated Microgravity, Tyler Jenkins

Student Research Symposium (SRS)

Simulated microgravity presents multiple physiological stressors for astronauts, including bone demineralization, muscle loss, and weakening of the immune system (Chavez et al., 2024). Bacteria serve as viable model organisms to study physiological changes because of their abundance in the human digestive system and skin. Motility in bacteria plays a significant role in cell survival, but few studies have been conducted on microgravity’s effect on motility phenotypes. While motile strains like K12 have been studied extensively under microgravity conditions (Topolski et al., 2022; Chavez et al., 2024), the effects of simulated microgravity on non-motile strains are largely unknown. To better understand …

Waters At Risk: Preventive Methods Against Cyanobacteria Blooms In Rhode Island, Ryan Boline

CAFE Symposium 2026

This project analyzes the rise of cyanobacteria blooms in Rhode Island freshwater systems and identifies a policy gap in the state’s largely reactive management approach. Drawing on state reports and interviews with environmental experts, it highlights nutrient runoff, climate change, and limited public education as key drivers of bloom severity. To address this gap, I developed a prevention-focused public education poster designed for integration into existing state alert and outreach systems.

Development And Evaluation Of Lipid Nanoparticle-Encapsulated Dna Vaccines For Avian Influenza In Chickens, Sushmita Kumari

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Avian influenza virus (AIV) remains a major challenge for global poultry health, food production, and agricultural economies. Both low-pathogenic (LPAIV) and highly pathogenic (HPAIV) strains continue to circulate and evolve, creating an ongoing need for vaccines that can be updated quickly and provide broad protection. Although DNA vaccines offer a safe and flexible approach to rapidly incorporate new antigens, their use in poultry has been limited by poor delivery efficiency and the vulnerability of naked DNA to degradation. Lipid nanoparticles (LNPs), which have proven highly effective for mRNA delivery, offer a promising solution, yet their potential for DNA delivery in …

Immunogenicity And Efficacy Of A Rabies-Based Vaccine Against Highly Pathogenic Influenza H5n1 Virus, Nir Paran, Christoph Wirblich, Randy Albrecht, Leila Zabihi Diba, Alessandro Tarquinio, Drishya Kurup, Charalambos C. Solomides, Adolfo García-Sastre, Matthias J. Schnell

Department of Microbiology and Immunology Faculty Papers

The recent spillover of highly pathogenic influenza A/H5N1 (HPAI-H5N1) viruses to cattle, other mammals, and humans poses a major risk to animal and human health. Virus adaptation to new species highlights the need for effective vaccines for animals and humans. We recently developed a rabies virus-based H5 vaccine encoding the HPAI-H5 antigen and presenting it on the surface of the rabies virus particle. To test the immunogenicity and efficacy of the vaccine in eliciting systemic and mucosal immune response, we vaccinated mice intramuscularly or intranasally with either live or inactivated and adjuvanted vaccine. The vaccine elicited neutralizing antibodies against RABV …

Humanity Is Evolving Its Consciousness: The Role Of Archetypal Energies As Guides During An Unfolding Weeding Out And Alignment Process, Carroy U. Ferguson

Psychology Faculty Publication Series

Humanity is evolving its consciousness at individual and collective levels.  Given these seemingly tumultuous times, as of this writing (January 2026), to make such a statement may sound like a strange thing to say.  However, I suggest that if you are alive today and if you are reading these words, these are the very times for which you were born—to assist Humanity as it evolves its consciousness with your unique gifts, whatever they may be.  That is, this period of our individual and collective human being-ness may be characterized as an unfolding period of weeding out and alignment with the …

Combined Glycoprotein Mutations In Rabies Virus Promote Astrocyte Tropism And Protective Cns Immunity In Mice, Mirjam Anna Rita Bertoune, Corinna Kolbe, Ann-Cathrin Werner, Maren Steinmetz, Bernhard Dietzschold, Eberhard Weihe

Department of Microbiology and Immunology Faculty Papers

Rabies virus (RABV) causes fatal encephalitis once it invades the central nervous system (CNS), and treatment options are extremely limited at this stage. We investigated the recombinant RABV variants SPBN, SPBNGA (glycoprotein substitution R333E), SPBNGAK (R333E plus N194K), SPBNGAS (R333E plus N194S), and TriGAS (three copies of the R333E/N194S glycoprotein). We evaluated their cellular tropism and immune activation in an intracerebral mouse infection model using immunohistochemistry and confocal immunofluorescence. SPBNGAK (R333E/N194K) resulted in mixed neuronal and astrocytic infection and lethal disease. In contrast, the R333E/N194S mutations in the GAS variants were associated with reduced neuronal infection and apparent astrocyte-restricted infection …

Oral Streptococcus And Vitamin B12 Deficiency In E-Cigarette Users: A Microbial–Nutrient–Neurotransmitter Axis Linking To Mood Disturbances, Maryam Sabah Naser, Ali Jabbar Abd Al-Hussain Alkawaz, Ali Abbas Hashim Almusawi, Ali Jalil Obaid, Hasanain Ayed Mohammed Al-Khafaji, Reihaneh Sabbaghzadeh

Karbala International Journal of Modern Science

Background: With the rising popularity of e-cigarettes, questions have emerged regarding their broader influence on oral ecology, nutrient absorption, and psychological health. Disruptions in the oral microbiome may alter vitamin B12 dynamics. This, in turn, may indirectly influence serotonin biosynthesis and mood regulation.

Methods: An observational cross-sectional study involved 150 young adults segregated into groups of 50 each as vapers, smokers, or non-users. Streptococcus sanguinis and vitamin B12 metabolism-related variable statuses methylmalonic acid and holotranscobalamin were quantified in samples, along with inflammatory markers interleukin-6, kynurenine/tryptophan ratio, and serotonin. Statistical techniques, including ANOVA and the Kruskal-Walli’s test, correlation, and serial mediation …

Biology Department Publications: 2025, Sam Lindgren

Biology Department Bibliographies

This document is a non-comprehensive list of publications made by graduate students, post-doctoral researchers, and faculty members in the Biology Department in 2024. It indexes those publications available through PubMed, and serves as an archival record of the Department's robust scholarly contributions.

Decoupling Of Reproduction And Lifespan Trade-Off In Caenorhabditis Elegans Through Microbial Programming, Nora M. Villafuerte

LSU Master's Theses

The microbiome is increasingly recognized as a major regulator of host physiology. Using the Caenorhabditis elegans model, we investigated how natural commensal bacteria modulate host reproduction and lifespan through internal egg hatching, a phenotype in which retained embryos hatch within the maternal body. Screening strains from the CeMbio collection identified four focal strains Ochrobactrum BH3, Lelliottia JUb66, Pantoea BIGb0393, and Enterobacter CEent1 that significantly increased internal egg hatching during the late reproductive period. This contrasts with pathogenic bacteria, which induce early-onset internal egg hatching. Across the focal strains, worms exhibited reduced total brood size but an expanded reproductive window relative …

Investigating Host Factors In Coronavirus Assembly And Egress, Surovi Binte Sharmin Mohona

Dissertations

Coronavirus (CoV) structural proteins congregate at the ER-Golgi intermediate compartments (ERGIC) prior to virus budding into the organelle lumen. Subsequent trafficking and fusion of virus-containing, ERGIC-derived vesicles then release nascent viruses from infected cells. Our findings in this dissertation illuminate mechanisms by which CoV structural proteins coalesce at the virus assembly and budding sites. The cytoplasmic tails of all CoV spike (S) glycoproteins contain variants of a consensus KxKxx coatomer-binding motif. Host coatomer complexes facilitate retrograde trafficking of client cargo proteins via recognition of such motifs. Utilizing reverse genetics methodologies, we introduced variations in the S coatomer motif in a …

An Examination Of Lysine Acetylation In The Context Of Bacterial Metabolism, Translation, And Regulation Of Gene Expression, Thomas Patrick Bank

Dissertations

Post-translational modifications are a critical tool bacteria employ to survive the challenges of microbial life. Acetylation continues to gain more recognition as a modification of unique importance because the sources of acetylation – acetyl-phosphate and acetyl-coenzyme-A – are critical metabolites associated with central carbon metabolism, acetate overflow metabolism and acetate assimilation. This suggests that acetylation, indelibly coupled to metabolic flux, integrates metabolic sensing with any cellular process or pathway where an acetylation alters the function of a protein. Intuitively, this makes sense. Of course, a bacterial cell would coordinate any cellular process closely with the amount of energy available to …

Antimicrobial Resistance Of Cultivable Bacteria Isolated From Sorcerer’S Cave In Texas, Jennifer R. Huddleston, David E. Sanderson, Braden J. Smith, Joshua M. Brokaw, Evan M. Babb, Jeffrey T. Wooliscroft

International Journal of Speleology

Studying caves with minimal human contact offers insights into antimicrobial resistance before human influence. In this study, we isolated 315 bacterial strains from Sorcerer’s Cave in Texas and evaluated their resistance to seven common antimicrobials. Under half (41.4%) of the Gram-positive isolates and 68.4% of the Gram-negative isolates were resistant to three or more antimicrobials. The two most common genera identified were Pseudomonas and Bacillus. Compared to bacteria isolated in previous cave studies, Sorcerer’s Cave bacteria exhibited more extensive antimicrobial resistance. This study underscores the importance of minimally disturbed cave environments in advancing our knowledge of antimicrobial resistance present …

Environmental Detection And Genetic Profiling Of Staphylococcus Sp. At Taal Volcano Island, Ray Albert E. La Rosa, Shaun Michael C. Basco, Martin Gabriel Z. Dela Cruz, Iluminada A. Ronio

The Lasallian Journal of Health

Taal Volcano Island’s hydrothermal environment supports extremophilic microbial communities. This study isolated, biochemically characterized, and genetically profiled Staphylococcus sp. from shoreline soils. Soil samples were collected near active vents and cultured on acidified gelatin agar (pH 5.0). Biochemical tests—Methyl Red, Spirit Blue Agar, Motility, and Acrolein—were performed. DNA extraction and 16S rRNA sequencing identified Staphylococcus candidatus, with 99 % sequence similarity to GenBank entries JN794602.1 and KX250303.1. Phylogenetic analysis clustered the isolate with S. ureilyticus, S. cohnii, and S. equorum. The organism’s presence in volcanic soils demonstrates adaptation to acidic, thermophilic conditions and suggests potential applications in bioremediation and enzyme …

Anti-Csf-1r Therapy With Combined Immuno-Chemotherapy Coordinate An Adaptive Immune Response To Eliminate Macrophage Enriched Triple Negative Breast Cancers, Diego A Pedroza, Xueying Yuan, Fengshuo Liu, Hilda L Chan, Christina Zhang, William Bowie, Alex J Smith, Sebastian J Calderon, Nadia Lieu, Weiguo Wu, Paul Porter, Poonam Sarkar, Na Zhao, Constanze V Oehler, Ondrej Peller, M Waleed Gaber, Qian Zhu, Charles M Perou, Xiang H-F Zhang, Jeffrey M Rosen

Faculty, Staff and Students Publications

Women diagnosed with metastatic triple negative breast cancer (mTNBC) have limited treatment options, are more prone to develop resistance and are associated with high mortality. A cold tumor immune microenvironment (TIME) characterized by low T cells and high tumor associated macrophages (TAMs) in mTNBC is associated with the failure of standard-of-care chemotherapy and immune checkpoint blockade (ICB) treatment. We demonstrate that the combination of immunomodulatory low-dose Cyclophosphamide (CTX) coupled with anti-CSF-1R antibody targeted therapy (SNDX-ms6352) and anti-PD-1 (ICB), was highly effective against aggressive metastatic Trp53 null TNBC transplantable syngeneic models that present with high macrophage infiltration. Mechanistically, CSF-1R inhibition along …

Exploring Alkaline Protease Activity Of Bacillus Strain Isolated From Sidon Dumpsite Lebanon, Zahra Farroukh, Dalia El-Badan, Jamilah Borjac

BAU Journal - Science and Technology

Proteases are crucial hydrolytic enzymes present in all organisms, performing essential physiological and industrial tasks. This study was conducted to screen and isolate protease-producing bacteria from soil and water samples collected from Sidon dumpsite in Lebanon. Bacterial samples were cultured onto skim milk agar medium to identify the alkaline protease-producing ones. In this study, we report on the partial purification and characterization of one of the isolated alkaline protease-producing bacteria. The bacterium was identified as Bacillus subtilis Z3 based on 16S rRNA sequencing. The molecular weight of the partially purified protease was approximately 55 kDa, estimated by sodium dodecyl sulphate …

Meta-Analysis Of Probiotic Yeast Factors And Methodologies, Mones J. Hajizadeh

Biology Theses

In recent years, there has been an expanding interest in ameliorating the gut microbiome through the use of yeast probiotics, in contrast to the general focus on bacterial probiotics. The goal of this paper is to determine trends and variations in the probiotic evaluation of the yeast species Kluyveromyces marxianus, Pichia kudriavzevii, and Saccharomyces cerevisiae var. boulardii across 48 studies, and determine probiotic gene homology amongst the three yeasts. Much of the literature on novel yeast strains employs various approaches to assess probiotic efficacy. In this study, the evolutionary divergence of these three species of interest was also evaluated. Furthermore, …

Antimicrobial Activity Of Violacein Extracted ​ From Janthinobacterium Lividum​, Catherine M. Brownhill-Slatore

Scripps Senior Theses

Abstract

Antibiotic-resistant bacteria have been a threat since the discovery of antibiotics. The increased rise of antibiotic-resistant bacteria has created an immediate need for new antibiotics. Violacein, a purple bisindole pigment produced by Janthinobacterium lividum, has been shown to be a promising new antibiotic. Its efficacy has not been completely demonstrated, and this project aims to further investigate the effectiveness of violacein as an antibiotic. To do this, a minimum inhibitory concentration (MIC) test was conducted. Violacein was grown, extracted, purified, and tested across concentrations ranging from 1.0 to 500.00 µg/mL to cover values well above and below previously cited …

Bacterial Community Function In Pitcher Plant Leaves As An Experimental And Mathematical Model Of Functional Dynamics, Amelia Jackson

Cal Poly Humboldt theses and projects

This work looks at two different sites with differing abiotic factors in measures of altitude, temperature and precipitation. The site with higher altitude, larger temperature range, and lower precipitation, located in Plumas National Forest (Quincy, CA), had a flat BEF trend that suggests functional redundancy The site with lower altitude, more moderate temperatures, and higher precipitation located in Six Rivers National Forest (Gasquet, CA), also had a flat BEF trend. These abiotic factors could correlate to the significantly different bacterial compositions between sites. The second portion of this work is modeling the host antagonist relationship between Eyxra moths and their …

Combining Crispr And Nanoasv To Uncover The Rare Bacterial Communities Of The Human Oral Microbiome, Gilma Ruth Sevilla Alvarez

Master's Projects

Studying the oral microbiome is vital because its health implications are not contained to the mouth. Cariogenic bacteria cause tooth demineralization and oral microbes that translocate to extra-oral organ systems are linked to conditions like Alzheimer’s disease, heart disease, diabetes, and cancer. Some of these pathogens belong to the most abundant phyla in the oral cavity: Bacillota, Pseudomonadota, Bacteroidota, Actinomycetota, Spirochaetota, and Fusobacteriota, which together comprise 94% of the oral microbiome. This project uses CRISPR-Cas9 to deplete sequences from highly abundant phyla and the Eubacteria domain, enriching the remaining 6% of rarer taxa. Paired with NanoASV for single-nucleotide resolution, this …

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 …

Exploring Biopsychosocial Influences On Hookup Culture And Disrupting Compulsory Behaviors In Emerging Adults: A Multidisciplinary Analysis Of A Contemporary Public Health Concern, Catherine Benjamin

Honors Theses and Capstones

Multidisciplinary analysis, including biology, psychology, and sociology, to better understand the compulsory Hookup Culture that exists as a contemporary public health concern among the age group defined as emerging adults. Sexually Transmitted Infections (STIs) diagnoses are steadily rising in the United States and disproportionately affecting college students. Early socialization and current educational resources that contribute to shame and stigma are discussed to explain how lifestyle and social conditions can act as risk factors for individual health outcomes.

Effects Of Volatile Organic Compounds Produced By Temperature-Adapted Microbes On Duckweed Growth, Phaedra Yael Stemp

Honors Theses and Capstones

As host-associated microbes adapt to their abiotic environment, these adaptations can affect their host species as well. Previous research showed that varying temperatures and volatile organic compound (VOC) production can affect microbial benefits to hosts. This experiment analyzed how 27 microbes pre-adapted to different temperature conditions affected growth of their host, common duckweed plants, comparing effects of direct contact with microbes, effects of microbe VOCs alone, or both. Each microbe was pre-adapted to one of three temperature regimes: “Northern” at 28 °C, “Southern” at 33 °C, and “Extreme” at 36 °C. We then grew duckweeds in I-plates with each microbe …

Investigating Microbe-Mediated Temperature Tolerance In Lemna Minor, Matthew Thomas Farbaniec

Honors Theses and Capstones

Temperature limits plant growth and survival more than many other environmental variables, and increases in the frequency of extreme hot or cold weather events pose significant challenges for plant growth and crop yields. Previous studies have shown that bacteria, fungi, and other microorganisms associated with plants ( i.e., the plant microbiome) can influence host response to temperature stress. These same microbes have their own temperature tolerances. We investigated whether microbial temperature tolerance correlates with plant resilience using an aquatic plant model, Lemna minor, and isolates derived from its microbiome. Microbial isolates were assessed at −10°C, 4°C, and 32°C for …

Influence Of Microbial Communities And Dilute Heavy Metals In Green Manure On Growth In Lactuca Sativa, Robert Lemay

Student Research Projects

This experiment investigated the effects of a green manure (Lemna minor, common duckweed) grown in varying levels of heavy metals and inoculated with local microbiomes on a crop (Lactuca sativa, volcana lettuce). The growth and health of the duckweeds were measured via root length and biomass, and the health of the lettuce crop was measured via head diameter and biomass.  Two levels of heavy metal concentrations were based on real-world stormwater runoff data to mimic an agricultural environment where accumulation of metals in local water bodies may be absorbed into green manure duckweeds. One microbial treatment and …

Modulating Oran Nitrate-Reducing Bacteria To Enhance Nitric Oxide Bioavailability As A Therapeutic Target For Atherosclerosis, Donovan C. Davidson

CMC Senior Theses

Atherosclerosis remains the primary driver of global cardiovascular disease, yet clinical interventions are largely restricted to high-cost, invasive procedures only after it has reached a critical stage. Recent research has identified a connection between the oral microbiome and vascular health via the enterosalivary nitrate-nitrite-nitic oxide (NO) pathway. Oral nitrate-reducing bacteria (ONRB) drive the synthesization of NO by reducing dietary nitrate into nitrite, which is then converted into bioavailable NO. NO is a potent vasodilator that maintains endothelial health by suppressing inflammation through inhibiting the expression of adhesion molecules VCAM-1 and ICAM-1. However, this pathway is easily compromised by dysbiotic oral …

The Rhesus Macaque Model Of Mycobacterium Avium Infection Reveals That Age-Related Disease Is Due In Part To Chronic Inflammation And Lung Microbial Dysbiosis, Ethan G. Napier

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Aging is associated with dysregulated immunity and increased susceptibility to infection, a phenomenon dubbed as immunosenescence and characterized by reduced naïve T and B cell pools, altered innate immune function, and chronic low-grade inflammation. Nontuberculous mycobacterial (NTM) pulmonary disease (NTMPD) is an increasingly relevant chronic lung infection that disproportionately affects older adults (65+ years) and immunocompromised individuals. However, the host factors underlying increased disease severity in aged patients remain poorly defined. Literature suggests that effective control of NTM relies on coordinated innate and adaptive immune responses, particularly macrophage activation and Th1 cytokine signaling. Using a rhesus macaque model that closely …

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 …