Microbiology Commons^™

Antimicrobial Eats: How Food Additives Are Contributing To Obesity Via The Gut Microbiome, Olivia Mankos

Senior Honors Theses

The typical modern diet is brimming with food additives used in food processing. Additives such as antibiotic residues, GMOs, pesticide residues, anti-caking agents, emulsifiers, artificial sweeteners, colorants, flavor enhancers, and preservatives. Most of these additives seem to shift the gut microbiome towards more pro-inflammatory signals. When all these additives are considered as an amalgam, such as with the modern processed diet, the ramifications on the gut microbiome are concerning. Obesity, which is characterized by low-level chronic inflammation, is likely exacerbated by these food additives. Consequently, most of these additives should be avoided or banned for optimal health.

Mechanisms Of Behavioral Change In Hosts Of Toxoplasma Gondii: A Review, Olivia Grimsley

Senior Honors Theses

The parasite Toxoplasma gondii is a highly ubiquitous parasite that latently infects an estimated 33% percent of the global population. Toxoplasmosis is of obvious clinical significance due to the extremely high risks to the unborn who contract it congenitally. Less attention has been given to a more subtle aspect of latent infection, which is the behavioral alterations that are commonly experienced by those who contract the parasite. Infected individuals commonly display a variety of altered behaviors, such as increased aggression and risk-seeking behaviors, depression, higher tendency towards suicide and self-directed violence, a loss of fear response, and a greatly increased …

The Roles Of Rnt1 And Putative Endoribonucleases In Eukaryotic Mrna Degradation, Lee-Ann Notice-Sarpaning

Dissertations and Theses (Open Access)

Endoribonucleases initiate degradation by cleaving RNAs internally. Mutations in these enzymes have been shown to cause diseases such as cancer, developmental disorders, and neurodegenerative diseases. Yet, eukaryotic endoribonucleases have not been well studied, especially with regard to their role in nuclear mRNA degradation. Rnt1 is a Saccharomyces cerevisiae (budding yeast) nuclear endoribonuclease and homolog of human Drosha with well-characterized roles in the processing of ncRNAs. The enzyme recognizes and cleaves double-stranded RNA stems containing a terminal tetraloop with an AGNN consensus sequence. However, the scope and consequence of its function in mRNA degradation has heretofore been unclear. Previous studies have …

The Contribution Of De Novo Coding Mutations To Meningomyelocele, Yoo-Jin Jiny Ha, Ashna Nisal, Isaac Tang, Chanjae Lee, Ishani Jhamb, Cassidy Wallace, Robyn Howarth, Sarah Schroeder, Keng Ioi Vong, Naomi Meave, Fiza Jiwani, Chelsea Barrows, Sangmoon Lee, Nan Jiang, Arzoo Patel, Krisha Bagga, Niyati Banka, Liana Friedman, Francisco A Blanco, Seyoung Yu, Soeun Rhee, Hui Su Jeong, Isaac Plutzer, Michael B Major, Béatrice Benoit, Christian Poüs, Caleb Heffner, Zoha Kibar, Gyang Markus Bot, Hope Northrup, Kit Sing Au, Madison Strain, Allison E Ashley-Koch, Richard H Finnell, Joan T Le, Hal S Meltzer, Camila Araujo, Helio R Machado, Roger E Stevenson, Anna Yurrita, Sara Mumtaz, Awais Ahmed, Mulazim Hussain Khara, Osvaldo M Mutchinick, José Ramón Medina-Bereciartu, Friedhelm Hildebrandt, Gia Melikishvili, Ahmed I Marwan, Valeria Capra, Mahmoud M Noureldeen, Aida M S Salem, Mahmoud Y Issa, Maha S Zaki, Libin Xu, Ji Eun Lee, Donghyuk Shin, Anna Alkelai, Alan R Shuldiner, Stephen F Kingsmore, Stephen A Murray, Heon Yung Gee, W Todd Miller, Kimberley F Tolias, John B Wallingford, Spina Bifida Sequencing Consortium, Sangwoo Kim, Joseph G Gleeson

Faculty, Staff and Students Publications

Meningomyelocele (also known as spina bifida) is considered to be a genetically complex disease resulting from a failure of the neural tube to close. Individuals with meningomyelocele display neuromotor disability and frequent hydrocephalus, requiring ventricular shunting. A few genes have been proposed to contribute to disease susceptibility, but beyond that it remains unexplained1. We postulated that de novo mutations under purifying selection contribute to the risk of developing meningomyelocele2. Here we recruited a cohort of 851 meningomyelocele trios who required shunting at birth and 732 control trios, and found that de novo likely gene disruption or …

Differential Progression Of Pancreatic Premalignancy In Geographically Distant Murine Transgenic Cohorts Uncovers Key Role Of Microbial Metabolites, Rian M. Howell

Dissertations and Theses (Open Access)

Cancer is a leading cause of death worldwide. Despite recent advances in diagnostic and therapeutic modalities, pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer that remains highly lethal. Efforts have been made to increase the understanding of the underlying mechanisms driving early stages of tumor development, when the cancer is most susceptible to intervention. To this end, genetically engineered mouse models (GEMMs) have been developed with the mutations most commonly seen in the patient population. Expression of these mutations in select cellular compartments has resulted in the ability to recapitulate characteristics of human pancreatic cancer such as the development of …

Bacterial Chondronecrosis With Osteomyelitis In Broilers: Etiology And Selected Mitigation Measures, Khawla Saud Alharbi

Graduate Theses and Dissertations

Bacterial chondronecrosis with osteomyelitis (BCO) is the predominant cause of lameness in broiler chickens. It mainly impacts broiler production and animal welfare, causing substantial financial losses accounting for 1- 2% due to bird condemnations at the marketing age. Remediating BCO lameness disease demands investigating its causes using appropriate models and evaluating preventive measures, such as enhancing epithelial tissue health and tight junction integrity in the digestive and respiratory tract, strengthening immune functions, and improving bone strength. Therefore, the objectives of this dissertation were to 1) study predisposing factors for BCO lameness by investigating the effects of deoxynivalenol (DON) and fumonisin …

Characterization Of Streptococcus Gallolyticus: An Emerging Pathogen Causing Turkey Streptococcosis, Latasha S. Gray

Graduate Theses and Dissertations

During the past five years, there has been an increased occurrence of Streptococcus gallolyticus in young turkey poults. This emerging pathogen previously affected turkey flocks without any indication of disease prior to acute mortality. However, recently there has been two cases of neurological presentation associated with S. gallolyticus subsp. pasteurianus that are unique to traditional disease presentation in turkey poults. The objectives of the present dissertation were to compile data associated with the two neurological cases and compare different S. gallolyticus strains as well as pathogenic Enterococcus cecorum to the neurological strains. The two neurological cases occurred between July and …

Seasonal Detection Of Coliphages In Freshwater Bodies At Coastal Carolina University, Ella Caldwell

Honors Theses

Bacteriophages, commonly referred to as phages, are non-living viruses that only infect bacteria. As the most abundant biological entities on Earth, understanding their role in regulating microbial populations is essential. This ongoing research aims to identify naturally occurring bacteriophages that could effectively control bacteria blooms. The primary objective of this study is to detect coliphages on Coastal Carolina University's campus and determine their viral families. Coliphages are a subgroup of bacteriophages that specifically infect coliform bacteria. Water samples were collected across multiple sites on campus, and polymerase chain reaction (PCR) was employed to amplify the viral DNA from the potential …

Can Chaperones Promote Protein Splicing?, Hazel Thomas

Honors College Theses

Inteins are a mobile genetic element hypothesized to function as regulatory molecules in microbes. They bear a homing endonuclease domain for genome traversal, as well as specific residues allowing for protein splicing. In the protein splicing reaction, the intein is removed and the flanking residues, termed exteins, are ligated together with a peptide bond to form a functional host protein. Due to their interruption prior to splicing, inteins prevent a host protein from functioning until the intein ligates the two exteins. To measure factors that regulate protein splicing in vivo, an intein-based biosensor based on kanamycin resistance (K …

Bibliometric Analysis Of Research Trends Related To Human Immunodeficiency Virus., Madyson E. Johnson, Kaitlyn R. Coffman, Valerie Rivas, Elizabeth Barrett

ATU Scholars Symposium

Human immunodeficiency virus poses major health burden across the globe including the United States of America and has its zoonotic origin from the Simian Immunodeficiency viruses of sooty mangabey monkey and chimpanzee in Africa. Epidemiological trends indicate that even though the mortality rates for HIV are falling globally, the rates of new cases have been rising since 2010 in several countries including the USA. An estimated 0.5% of the human population is currently infected with the virus with countries like USA, India, Nigeria and South Africa carrying the highest burden of the disease. Host receptors such as CD4 and coreceptors …

Bacterial Microbiomes In Different Depths Of Sand At The Mississippi Gulf Coast, Hays S. Roth

Honors Theses

Microbial communities in sand play essential roles in their ecosystems, yet little is known about how bacterial diversity and function vary across different sand depths. This study investigated bacterial microbiomes at varying depths (0, 10, 20, 30, and 40 cm) on Biloxi East Beach, on the Mississippi Gulf Coast, using 16S rRNA gene sequencing and assays of extracellular enzyme activity. 11,161 amplicon sequence variants (ASVs) were identified across all samples, with the most abundant bacterial phyla being Planctomycetota, Gammaproteobacteria, and Bacteroidota. Depth had a significant impact on bacterial community composition, with surface layers having more diverse bacterial communities. Microbial diversity …

Expression, Characterization, And Comparative Analysis Of Bacillus Bacteriophage Endolysins, Stephen D. Zdgiebloski

Research and Creativity Symposium

Bacteriophages present a promising alternative for combating antibiotic-resistant bacteria without disrupting the normal microbiome or harming human cells. The antibacterial properties of lytic bacteriophages are largely attributed to endolysins, enzymes active in the lytic cycle. Endolysins recognize bacterial cell walls and cleave the peptidoglycan matrix, leading to cell wall disruption. Their specificity and effectiveness against bacterial hosts are determined by two functional domains, including the cell wall binding domain. Our research focuses on characterizing Bacillus phage endolysins. We analyzed the protein sequences of endolysins from six Bacillus phages isolated at the University of Mary Washington. Although these phages were isolated …

From Dysbiosis To Dysfunction: Investigating The Effects Of Chronic Cocaine Use On Oral Microbial Shifts And Neuropathogenesis, Douglas E. Johnson

MUSC Theses and Dissertations

Cocaine use disorder remains a significant public health challenge. However, the mechanisms by which chronic cocaine use contributes to neuroinflammation and cognitive decline are still not fully understood. Chronic non-intravenous cocaine use is associated with oral microbial dysbiosis. Although the gut-brain axis has been widely studied, the impact of cocaine-mediated shifts on the oral microbiome on systemic and neuroinflammation remains a significant yet largely unexplored gap. This dissertation investigates the hypothesis that cocaine-specifically enriched oral Streptococcus parasanguinis triggers neuroinflammation, neuropathology, and cognitive deficits. In a human study, the saliva microbiomes from chronic cocaine users exhibited reduced α-diversity, enriched Streptococcus genus, …

Survey And Analysis Of Rumen Microbiota In Yaks At Different Growth Stages, Shengwei Jin, Xinyue Liu, Yin-Cang Han, Yong-Gang Sun, Wei-Qin Ding, Ya-Qian Liu, Fa-Jie Gou, Jian-Yu Chen

The Thai Journal of Veterinary Medicine

This study investigated changes in the richness and composition of the rumen microbiome in yaks at various developmental stages. Eighteen healthy male yaks at the ages of 5 months (M5), 12 months (M12), and 24 months (M24) had samples of their rumen digesta taken for 16S rRNA gene sequencing. The 11087 amplicon sequence variations (ASVs) in total were found; the M5, M12, and M24 groups had 3585, 1146 and 5545 distinct ASVs, respectively. Alpha diversity indices Chao, Shannon, Sobs, and ace indicated significant differences among the groups. The principal coordinate analysis (PCoA) indicated significant changes in microbial community composition across …

Emergence Of Heterogeneity In Bacteria During Antibiotic Exposures, Mirjana Stevanovic

Dartmouth College Ph.D Dissertations

Bacterial populations exposed to antibiotics often exhibit phenotypic heterogeneity, with individual cells displaying distinct responses with fates ranging from survival to arrest or death. The emergence of this heterogeneity is largely driven by feedback mechanisms mediated by the interactions between antibiotic action, gene regulation, and cellular metabolism. These responses unfold in dynamic environments where conditions such as nutrient availability and drug concentration fluctuate over time and space. Yet, these complex interactions and their role in shaping population-level outcomes during drug responses remain poorly understood. Using tetracycline resistance in E. coli as a model system, this thesis focuses on how these …

Progesterone Signaling In Oviductal Epithelial Cells Modulates The Immune Response To Support Preimplantation Embryonic Development, Emily A Mcglade, Jiude Mao, Kalli K Stephens, Ryan M Marquardt, Feyza Nur Arguc, Peter F Lais, San-Pin Wu, Sarayut Winuthayanon, Haval Shirwan, Esma S Yolcu, Mark I Hunter, James K Pru, John P Lydon, Francesco J Demayo, Wipawee Winuthayanon

Faculty, Staff and Students Publications

More than 60% of pregnancy losses occur during the first trimester, highlighting the need to understand the role of the oviduct in early pregnancy. In this study, we conditionally ablated the classical progesterone receptor (Pgr) in oviductal epithelial cells, called the Pgrd/d mouse model. We found that 40% of embryos collected from Pgrd/d females were nonviable or developmentally delayed, indicating that epithelial PGR expression is crucial for embryonic development. Single-cell RNA sequencing revealed up-regulation of proinflammatory genes, including interleukin-22 (IL-22), in the epithelial cells of Pgrd/d females. Pharmacological inhibition of inflammation using nonsteroidal anti-inflammatory drugs …

Antibiotic Resistance Testing And Enumeration Of E. Coli, Coliforms, And Salmonella In Canada Geese Feces Based On Natural Water Sources And Retention Ponds, Ceejay Ritzke

Research Days

Canada Geese (Branta canadensis) are migrating birds. They can transmit antibiotic resistant bacteria when they are traveling. They do this by ingesting antibiotic resistant bacteria that is on the food they eat in one area, and then excrete some of it at the next place they travel to. Retention ponds have increased amounts of antibiotic-resistant bacteria that Canada geese can pick up if they stop there while migrating. Canada geese that land at a retention pond should have an increased amount of antibiotic resistance compared to landing at a natural water source. Their feces were tested in eight different areas …

Investigating The Effect Of Soil Origin On Antibiotic Production In Streptomyces, Emu Suzuki

Undergraduate Research Symposium 2025

Streptomyces bacteria produce antibiotics that inhibit competing microorganisms. We hypothesized that Streptomyces from the rhizosphere (around plant roots) would be more likely to produce antibiotics than those from bulk soil (further away from roots). Soil samples were collected from rhizosphere and bulk soils in transitional and long-term organic fields of corn and alfalfa. Streptomyces from these soils were cultured on glucose-asparagine agar media. Their antibiotic production was evaluated by testing whether they could inhibit the growth of two target Streptomyces strains. No significant effects of soil type (rhizosphere vs. bulk), crop, or management on antibiotic production were observed for one …

Life After Death: Investigating The Resistance And Recovery Of Fungal Communities To Foundation Tree Mortality, Jessie F. Marlenee

Biology ETDs

Tree mortality can have cascading effects on the composition and resilience of interacting fungal communities. Yet, little is known about the impact tree mortality, distinct from abiotic drivers (i.e., drought), has on these communities. This dissertation focuses on the resilience of fungal communities to experimental tree mortality in a piñon-juniper woodland. In chapter one, I found that piñon mortality reduced piñon fine root biomass and piñon mycorrhizal fungal diversity, whereas juniper mycorrhizal fungi were unaffected by juniper mortality. In chapter two, I revealed that piñon mortality altered the composition and spatial structure of mycorrhizal and saprotrophic fungi in the soil, …

Lineage Tracing And Single-Cell Rna Sequencing Reveal A Common Transcriptional State In Breast Cancer Tumor-Initiating Cells Characterized By Ifn/Stat1 Activity, Eric P Souto, Ping Gong, John D Landua, Ramakrishnan Rajaram Srinivasan, Abhinaya Ganesan, Lacey E Dobrolecki, Stephen C Purdy, Xingxin Pan, Michael Zeosky, Anna Chung, S Stephen Yi, Heide L Ford, Michael T Lewis

Faculty, Staff and Students Publications

A tumor cell subpopulation of tumor-initiating cells (TIC) or "cancer stem cells" is associated with therapeutic resistance, as well as both local and distant recurrences. Signal transducer and activator of transcription (STAT) activity is elevated in TICs in claudin-low models of human triple-negative breast cancer, which enables enrichment of TICs using a STAT-responsive reporter. Lineage tracing of TICs as they undergo cell state changes could enable a better understanding of the molecular phenotypes of TIC and uncover strategies to selectively target TICs. In this study, we developed a STAT-responsive lineage-tracing system and used it in conjunction with the original reporter …

From Microplastic Impacts To Biodegradation Solutions: Investigating Microplastic Contamination, Microbial Responses, And Efficacy Of Synthetic Microbial Consortia In Plastic Degradation, Rener Sahot De Jesus

Thesis/ Dissertation Defenses

Plastics, including microplastics, pose significant environmental threats due to their widespread presence and harmful ecological effects. This dissertation present three distinct, yet interconnected studies. First, a study on microplastic contamination in urban recreational parks was conducted in Al Ain, UAE. Results showed that low-density microplastics were present in 87% of soil samples, with FTIR analysis identifying synthetic polymers such as PE and PP. Additionally, these microplastics were found to negatively affect soil pH and moisture levels, emphasizing the need for enhanced monitoring and management strategies. Second, the effects of ground microplastics on Photobacterium leiognathi spp., a marine luminous bacterium, were …

Biology Department Publications: 2024, 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.

Genome Analysis Of Aeromonas Hydrophila Strain S14-452, Zarin Tasnim Raya

Undergraduate Research Conference

The Aeromonas hydrophila are gram-negative, opportunistic bacteria that can infect many groups of organisms, mainly fish and amphibians. In channel catfish, A. hydrophila causes fatal bacterial septicemia, leading to massive economic losses for catfish farmers. Therefore, an understanding of its genome will aid in identifying its virulence factors, metabolic pathways and survival mechanisms within the host. This study details the draft genome sequence of A. hydrophila strain S14-452, isolated from channel catfish exhibiting bacterial septicemia during a disease outbreak at a catfish farm.

A. hydrophila strain S14-452 was sequenced using the Illumina iSeq 100 System. Assembly was performed with SPAdes, …

Discovery And Identification Of Muwow Bacteriophage From Columbus, Ms, Olivia Reese Carlisle, Jess Holden Collins, Kaliyah J. Moore, Nykeria J. Pratt

Undergraduate Research Conference

Bacteriophages are an abundant type of virus with the ability to infect and kill bacteria while using them to replicate through lytic or lysogenic processes. Bacteriophages play a key role in the regulation of bacterial populations in various environments and are being explored as potential tools in phage therapy. The aim of this study was to isolate, characterize, and manually annotate the genome of the bacteriophage MUWow collected from the campus of the Mississippi University for Women in Columbus, MS at GPS coordinates 33.493021 N, 88.419611 W. MUWow was isolated from a soil sample on Arthrobacter globiformis B-2979. Plaque assays, …

Pseudomonas Parafulva Confirmed To Have Antifungal Properties When Grown In Conjunction With Botrytis Cinerea, Caden Dupee, Kylee Eldredge, Zachary Elmer, Joshua Hartvigsen

Student Research Symposium

Widespread antibiotic use has led to antibiotic resistance of infectious bacteria. (Young, 2017) As part of the TinyEarth Program, the lab group collected and tested local soil samples for bacteria with hopes of finding novel antibiotic properties. From the soil samples, a bacteria was isolated, subsequently sequenced, and determined to be Pseudomonas parafulva. P. parafulva is a Gram-negative bacterium that has been known to frequent rice paddies of eastern Asian countries and has been collected in select regions of North America, including that of Cache Valley. P. parafulva has been linked to anti-fungal activities on plants. (Lui et …

Internship As An In-Vivo Technician At The Institute For Antiviral Research, Ashlynn Clark

Student Research Symposium

The Institute for Antiviral Research (IAR), located at Utah State University, specializes in evaluating antiviral agents and vaccines against a wide array of human pathogenic viruses, such as influenza, enterovirus, West Nile virus, yellow fever, zika virus, polio, and SARS-CoV-2, utilizing in vivo and in vitro models.

Identifying Compensatory Mutations In The Envelope Protein Of Japanese Encephalitis Virus That Restore Neurovirulence, Nathan Taylor, Jiyoun Kim

Student Research Symposium

• Japanese Encephalitis Virus (JEV) is a positive sense, single stranded Enveloped virus

Vaccine Stabilization With Spider Silk, Mallory Wootton

Student Research Symposium

Most vaccines must be stored between 2 - 8°C to maintain their efficacy, with some vaccines requiring temperatures as low as -70°C for long-term storage. These temperature requirements pose issues for vaccine distribution, notably to remote/rural areas, in hotter climates, and low- and middle-income countries which are largely dependent on vaccine imports. [1]

Distributor-Specific Variability In Balb/C Mouse Mortality Following Sars-Cov-2-Ma10 Infection, Taylor Kerr

Student Research Symposium

In recent years SARS-COV-2 has become a rapidly expanding area of research. To model human infections, this virus was adapted to mice enabling valuable insight into these processes.² Mice are often an effective research model due to their low cost, short reproduction time, and ability to adapt to a wide variety of viruses. Research into these immunological responses is crucial in developing vaccines, treatments, and furthering our understanding of this virus' behavior.¹ However, genetic variability in mouse models may be confounding previous and on-going research.

Mdpk Cell Lines Can Be Used For In Vitro Antiviral Testing With Highly Pathogenic Avian Influenza (H5n1), Jada L. Westover

Student Research Symposium

• Outbreak in agricultural poultry starting in 2022
• In March 2024 first confirmed case in Dairy Cattle
• Tested drugs T705, Oseltamivir, Baloxivir, Ribavirin, EIDD-2947, and EIDD-2749 on three different cell lines
• Goal: See if MDBK cell lines could be used for in vitro studies