Life Sciences Commons^™

Developing Disinfection Strategies For Controlling Human Norovirus, Sars-Cov-2, And Clostridioides Difficile Endospores In Long-Term Care Facilities, Jinge Huang

All Dissertations

Long-term care facilities (LTCFs) provide an environment favorable for the transmission of three critical human pathogens: human norovirus (HuNoV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and Clostridioides difficile. Given residents in LTCFs are susceptible to infections due to their advanced ages and compromised immune systems, effective environmental surface disinfection plays a crucial role in controlling the spread of human pathogens within these settings and, therefore, mitigates the risk of infections caused by these pathogens. This dissertation aimed to assess the efficacy of various types of disinfectants against two HuNoV surrogates [feline calicivirus (FCV) and Tulane virus (TuV)], two …

Effect Of Authentic Kefir And Nigella Sativa On Broilers Challenged By Coccidia And Clostridium Perfringens, Julian E. Nixon

All Dissertations

Black seed oil concentrations of 0%, 0.1%, 1% and 5% were added to milk inoculated with kefir grains and incubated at 25°C for 22 h. The pH and microbial count indicated 1% black seed oil caused low inhibition (P > 0.05) of fermentation, but 5% black seed oil caused significant inhibition of the kefir microorganisms (P < 0.05).

Cobb 500 male chicks (n = 256) were distributed in a randomized block design and received one of four treatments: CTRL1 (Non-medicated, no kefir, no Clostridium perfringens), CTRL2 (Non-medicated, no kefir, C. perfringens inoculated), CTRL3 (BMD medicated, no kefir, C. perfringens inoculated), KTRT (Non-medicated, …

Investigating The Role Of Cytochrome P450 Enzymes In Triazole Drug Efficacy And Toxicity In Whole Organism Zebrafish Model, Heather Cosh

Honors College Theses

Invasive fungal infections account for nearly 1.5 million deaths a year and therefore are considered one of the leading causes of death worldwide. The first line of therapy towards these infections are antifungal drugs in the triazole class such as voriconazole, posaconazole, itraconazole, and isavuconazole. However, these antifungal drug therapies fail in a large number of patients and can produce toxic side effects, therefore increasing the risk of mortality worldwide. While prior research has demonstrated the efficacy of these drugs in mitigating fungal growth in vitro, it is unclear why these drugs fail to protect patients infected with fungal …

Disinfectant Efficacy Against Sars-Cov-2 Surrogates, Bovine Coronavirus And Human Coronavirus Oc43, On Hard And Soft Non-Porous Surfaces, Breanna Kimbrell

All Theses

The novel human coronavirus (HCoV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged from Wuhan, China in the latter part of 2019. The rapid spread of SARS-CoV-2 amid the most recent COVID-19 pandemic forced countless foodservice establishments (FSEs) across the United States to close, taking a tremendous toll on the foodservice industry. Although primarily transmitted person-to-person, previous studies indicate that the duration of SARS-CoV-2 survival on different environmental surfaces provides adequate time for secondary transmission to occur. To prevent the further spread of SARS-CoV-2, effective disinfection of surfaces in FSEs is necessary. While disinfectants approved for use against SARS-CoV-2 are …

Development Of A Novel Fluorescent Reporter Baculovirus Vector For Testing Promoters In Lepidopterans, Daniel Howard

All Theses

Testing gene expression patterns is an important process in learning more about an organism. The standard methods of rtPCR and RNASeq provide highly detailed data on specific expression patterns, but can be resource consuming if many different samples including genes or organisms must be tested. A potential alternative for studying expression is the use of a reporter system carried by a vector system that encodes fluorescent proteins under the control of promoters of interest. Many lepidopterans (moths) are pestiferous and better understanding of gene expression levels in lepidopterans, both endogenous and exogenous including from their viruses, would be beneficial. Baculoviruses …

Generation And Characterization Of A Multi-Functional Panel Of Monoclonal Antibodies For Sars-Cov-2 Research And Treatment, Lila D. Patterson

All Theses

The Coronavirus disease 2019 (COVID19) pandemic caused by SARS-CoV-2 is an ongoing threat to global public health. To this end, intense efforts are underway to develop reagents to aid in diagnostics, enhance preventative measures, and provide therapeutics for managing COVID-19. The recent emergence of SARS-CoV-2 Omicron strains with enhanced transmissibility, altered antigenicity, and significant escape of existing monoclonal antibodies and vaccines underlines the importance of the continued development of such agents. The SARS-CoV-2 spike protein and its receptor binding domain (RBD) are critical to viral attachment and host cell entry and are primary targets for antibodies elicited from both vaccination …

The Effects Of Tubulin Post-Translational Modifications On The Flagellar Motility Of Trypanosoma Brucei, Katherine Wentworth

All Theses

Trypanosoma brucei is a parasitic kinetoplastid that causes African trypanosomiasis and is transmitted to a mammalian host by the tsetse fly (Glossina spp.). T. brucei relies on its flagellar motility to carry out its morphological changes from the procyclic form (predominant in the fly vector) to the bloodstream form (infectious form in mammals) and navigate the bloodstream of its host. The driving structure within the flagellum is the axoneme, which is composed of microtubules and dynein motor proteins. The tubulin code hypothesis suggests that cells regulate microtubule motor protein activity through post-translational modifications (PTMs) of alpha and beta …

The Cryptococcus Neoformans Flc1 Homologue Controls Calcium Homeostasis And Confers Fungal Pathogenicity In The Infected Hosts, Piotr R. Stempinski, Kristie D. Goughenour, Lukas M. Du Plooy, J. Andrew Alspaugh, Michal A. Olszewski, Lukasz Kozubowski

Open Access Publishing Fund

Cryptococcus neoformans, an opportunistic yeast pathogen, relies on a complex network of stress response pathways that allow for proliferation in the host. In Saccharomyces cerevisiae, stress responses are regulated by integral membrane proteins containing a transient receptor potential (TRP) domain, including the flavin carrier protein 1 (Flc1), which regulates calcium homeostasis and flavin transport. Here, we report that deletion of C. neoformans FLC1 results in cytosolic calcium elevation and increased nuclear content of calcineurin-dependent transcription factor Crz1, which is associated with an aberrant cell wall chitin overaccumulation observed in the flc1Δ mutant. Absence of Flc1 or inhibition …

Microbial, Chemical, And Functional Components In Kefir, Natto, And Feed Ingredients, Dana Mccurdy

All Dissertations

Kefir grains were purchased from online, home kitchen vendors in the United States (n = 22), inoculated into UHT milk, and incubated at 25°C for 22 hours. Results indicated lactobacilli, lactococci and yeast in all samples. Six out of 11 samples contained coliform, and all samples contained pseudomonal and staphylococcal species. Using targeted genome sequencing (16S) of kefir grain samples 1, 2, and 3 revealed that lactobacilli were the predominant genera of bacteria. ITS sequencing revealed different fungal species in each grain. Results indicated potential presence of menaquinone-4 and menaquinone-7 by UPLC-MS/MS analysis.

The fermentation of whole and ground soybeans, …

The Effects Of Short Chain Fatty Acids On Clostridioides Difficile Growth, Sporulation, And Toxin Production, Michelle Baldassare

All Theses

Short chain fatty acids (SCFAs) are products of bacterial fermentation that help maintain important gut functions such as the intestinal barrier, signaling, and immune homeostasis. The main SCFAs acetate, propionate, and butyrate have demonstrated beneficial effects for the host, including importance in combatting infections caused by pathogens such as Clostridioides difficile. C. difficile infection (CDI) is a public health concern and causes 30,000 deaths each year mainly due to the overuse of antibiotics. Despite the potential role of SCFAs in mitigating C. difficile infection, their direct effect on C. difficile remains unclear. Through a set of in-vitro experiments, we …

Application Of A 14c-Assay To Assess Methanotrophic Biodegradation Of Tce In Low Ph Groundwater, Evan Groome

All Theses

Current biological strategies for remediating trichloroethylene (TCE) in low pH aquifers (i.e., pH14C-TCE assay was developed to determine pseudo first-order rate constants for the degradation of TCE in microcosms containing soil and groundwater from the Boeing Michigan Aeronautical Research Center (BOMARC) superfund site, where the pH ranges from 4.1 to 4.9. The ¹⁴C-TCE assay was also adapted to calculate soil-normalized rate constants for data from this site, as well as data that Szwast²¹ collected from the Beltsville Agricultural Research Center (BARC). In addition to natural attenuation, biostimulation through amendments of methane and nutrients were also assessed. This treatment …

Reproductive Ecology And Microbial Communities From Wood Duck Nest Boxes In Georgia And Florida, Jake Shurba

All Theses

Wood ducks (Aix sponsa) are an important game species throughout the Atlantic Flyway that was nearly extirpated by the early 20^th century due to overhunting and the loss of habitat. Wood ducks are secondary cavity-nesters that utilize artificial nest boxes and natural cavities. It is reported that the use of nest boxes is likely what led to re-establishment of the species in North America. Where boxes are numerous, overuse of boxes by multiple hens throughout a nesting season can occur and result in a buildup of bacteria, parasites and other potentially detrimental pathogens that can impact egg …

Effects Of Continuous In Situ Low-Dose Ionizing Radiation On Microorganisms, Molly E. Wintenberg

All Dissertations

Precise detection and monitoring of nuclear fuel cycle, enrichment, and weapon development activities are critical for supporting warfighter preparation in chemical, biological, radiological, nuclear, and explosives (CBRNE) operations, clandestine activities, and nuclear compliance. A biological sensing system could serve as an alternative to traditional detection methods by using organic material naturally present in the environment to discreetly detect residual trace nuclear material. Microorganisms provide an optimal platform for an alternative sensing system; however, their response to low levels of ionizing radiation is poorly characterized. Combining the power of next-generation sequencing and transcriptomic analysis, this dissertation takes an approach to obtain …

Dynamics Of The Supragingival Dental Plaque Microbiome And Its Implications In Early Childhood Caries (Ecc), Lauren O'Connell

All Dissertations

Early childhood caries (ECC) is one of the most common chronic diseases worldwide and remains a serious public health crisis in developing countries and socioeconomically disadvantaged communities. Caries is a complex polymicrobial, sugar-driven disease caused by interactions between the biofilm and tooth surface. While there is a general understanding of the microbial processes driving dental caries development and progression, the microbiota associated with the initiation and progression of dental caries have yet to be fully characterized. The most-studied species associated with tooth health and disease are the oral streptococci. Nevertheless, there are still large gaps in our knowledge of the …

Identification Of Critical Points For Bacterial Contamination In The Microbrewery Environment, Alex Ryan Thompson

All Theses

There are 8,884 craft breweries producing over 23 million barrels of beer in the United States as of 2020. These 23 million barrels of craft beer account for 12.3% of the United States beer consumption in 2020. The American craft beer industry is substantial and needs to protect its product from bacterial contamination.

Overall, beer is a microbially stable product. Beers pH, ethanol levels, CO₂ concentrations, the presence of hop-derived antimicrobial compounds, and low levels of O₂ make beer a highly unfavorable environment for most bacterial species. Furthermore, the brewing process, which involves heat treatments and chemical sanitizers …

Glycan Functionalization Of Iron Oxide Nanoparticles (Ionps) As A Method Of Inactivating Antibiotic Resistant Neisseria Gonorrhoeae Via A Magnetically Mediated Energy Delivery (Magmed) System, Cedric Taylor

All Theses

With the increase of antibiotic resistant bacteria, current established therapeutic treatment methods are rapidly demonstrating decreasing efficacy. For this project, we are studying a novel alternate mechanism of treating antibiotic resistant bacteria by utilizing magnetic iron oxide nanoparticles (IONPs) coated with a heterobifunctional polyethylene glycol polymer (PEG) and functionalized with glycan structures that can interact with Neisseria gonorrhoeae FA1090. Interaction between the IONPs and bacteria is manipulated by an external alternating magnetic field (AMF) in a process known as magnetically mediated energy delivery (MagMED). Magnetic IONPs were synthesized and reacted with PEG (PEG-IONPs) and functionalized with glycans Gal(α1-3)Gal(β1-4)Glc(β1-1) (common name: …

Investigation Of Dissimilatory Iron Reduction By Exophiala Hkrs030, Zachary Burton

All Theses

Iron (Fe) is the fourth most abundant element in the Earth’s crust and is an essential component in many biological processes. While highly abundant, free iron is not readily available to biological systems since most iron is present in the earth’s crust in the form of ferrous (Fe2+) and ferric (Fe3+) iron minerals. Because of this limited availability, bacteria, plants and fungi have developed diverse ways to safely assimilate and store iron. Bacteria and some fungi have the ability to dissimilate iron. Dissimilatory iron reduction (DIR) is where Fe3+ is reduced to Fe2+ without the cell assimilating the Fe2+ and …

Bacterial Diversity And Ecology Of Two Cryptoendolithic Habitats In The Grand Staircase Escalante National Monument, Utah, Usa, Sukhpreet Kaur

All Dissertations

Sandstone outcrops in the Grand Staircase Escalante National Monument, Utah are host to cryptoendolithic communities dominated by cyanobacteria. These communities produce extracellular polymeric substances that not only aid their survival, but also support other heterotrophic bacteria. Developing a better understanding of the role of these cryptoendolithic communities requires a deeper knowledge of the microbial diversity present. We analyzed the cryptoendolithic bacterial communities in the Jurassic Navajo Sandstone samples collected from several microgeological features associated with a large sandstone dome. These communities clustered into distinctive groups that correlated with topography, suggesting that moisture availability plays an important role in shaping the …

Relationships Between Growth Rate And Gene Expression In Ruegeria Pomeroyi Dss-3, A Model Marine Alphaproteobacterium, Nattasha Vinas

All Theses

Microbes are important contributors to ecosystem processes such as biogeochemical cycling. Their activities vary, depending on environmental parameters such as carbon type and concentration, temperature, and salinity. Current estimates of in situ microbial growth is limited to gross estimates or rely on incubation based methods that disturb the natural state of the community. The goal of this master’s thesis is to develop molecular methods to directly assess microbial growth rates in the environment at the level of a taxonomic group. Here we grew Ruegeria pomeroyi DSS-3 under different temperatures (15 °C or 30 °C) and different carbon sources (yeast extract/tryptone, …

Phosphotransacetylase And Xylulose 5-Phosphate/Fructose 6-Phosphate Phosphoketolase: Two Eukaryotic Partners Of Acetate Kinase, Tonya Taylor

All Dissertations

Although acetate is a predominant metabolite produced by many eukaryotic microbes, far less attention has been given to acetate metabolism in eukaryotes than in bacteria and archaea. Acetate kinase (Ack), which catalyzes the reversible phosphorylation of acetate from ATP, is a key enzyme in bacterial acetate metabolism. Ack primarily partners with phosphotransacetylase (Pta), which catalyzes the generation of acetyl phosphate from acetyl-CoA, but can also partner with xylulose 5-phosphate/fructose 6-phosphate phosphoketolase (Xfp), which produces acetyl phosphate from either xylulose 5-phosphate or fructose 6-phosphate. The Ack-Pta pathway, found primarily in bacteria, is also present in lower eukaryotes such as the green …

Determining The Fate Of Non-O157 Shiga Toxin-Producing Escherichia Coli In Dairy Compost During Storage Using The Optimized Detection Method, Hongye Wang

All Theses

Shiga toxin-producing Escherichia coli (STEC), a member of Enterobacteriaceae family, has been recognized as emerging pathogens. Dairy compost is commonly applied to farmland as a soil amendment. Despite the agricultural benefit of manure-based soil amendment, the inadequately treated compost can contribute to fresh produce contamination on the farm. Moreover, the epidemiological results showed that the non-O157 STEC cases have surpassed those of E. coli O157. Therefore, it is critical to evaluate the behavior of non-O157 STEC strains in the dairy manure-based compost. The objectives of this study were to: 1) optimize a culturing method for detecting non-O157 STEC from dairy …

The Effects Of Probiotics Supplementation On Health Using Caenorhabditis Elegans As A Model System, Miranda Klees

All Theses

The 'Western Diet,' prominent among developed nations, often refers to a diet rich in meat proteins and refined sugars. Western society may in part be plagued with obesity and obesity related diseases due to a diet enriched with glucose. With an increasing glycemic index observed in Western society, it comes to no surprise that obesity, diabetes, heart disease, and other obesity related diseases are on the rise. The Centers for Disease Control and Prevention describes obesity as an epidemic, affecting more than 35% of U.S. citizens. Shortened lifespan and increased susceptibility to pathogens are associated with these diseases and linked …

Characterization Of Biofilms On Medical Device Materials With Application To Reusable Surgical Instruments, Amanda Macaluso

All Theses

Reusable medical devices or reprocessed single-use devices are original medical devices that have been used once and then are cleaned, sterilized, and remanufactured for the purpose of an additional single use on a single patient [4]. Improperly reprocessed devices are a significant contributor to hospital-associated infections [4]. Challenges that hinder reprocessing are related to the complexity of reusable medical device design, the necessary validation of cleaning protocols required by the U.S Food and Drug Administration (FDA), the impact of human factors throughout the reprocessing cycle, as well as economic factors within new business models that are centered on reprocessing. Current …

Inhibition Of Vibrio Cholerae Biofilm Formation By Water-Soluble Cranberry Extracts, Daniel Pederson

All Theses

Vibrio cholerae, a Gram-negative bacterium found in natural aquatic environments, is the causative agent of cholera, a severe diarrheal disease most commonly spread through drinking water. An essential component to this pathogen's success and persistence in the environment is its ability to attach to both biotic and abiotic surfaces via biofilm formation. Biofilms not only aid in surface attachment, but also provide a barrier that protects and enhances survival. Water-soluble extracts from the North American cranberry (Vaccinium macrocarpon) were found to dramatically inhibit V. cholerae biofilm formation at a low concentration of 2mg/ml. This inhibition was not due to acidification …

A Comparison Of Saponin And Tween 80 On The Solubility And The Degradation Enhancement Of Fluoranthene And The Influence Of Laccase On Fluoranthene Degradation, Stacia Ballew

All Theses

The ubiquitous contamination of polycyclic aromatic hydrocarbons (PAHs) in the environment require an economical approach as well as effective remediation techniques in the removal of these contaminants. Through the use of more eco-friendly and economically available biosurfactants, such as saponin, there is a possibility they could prove to be more useful surfactants than conventional synthetic surfactants for the solubilization of fluoranthene (FLA). Enhanced solubility would potentially facilitate the increased degradation by S. paucimobilis EPA505. The addition of laccase produced by Pleurotus ostreatus, a white rot fungus that produces enzymes known to facilitate or assist in the degradation of fluoranthene (FLA), …

The Role Of Human Norovirus Surrogates, Feline Calicivirus And Murine Norovirus, On Non-Porous And Soft Porous Surfaces, Thomas Yeargin

All Theses

Human Noroviruses (HuNoV) are the leading cause of acute gastroenteritis worldwide as well as the leading cause of foodborne disease in the U.S. HuNoV can persist in the environment even after proper disinfection, making preventing HuNoV infections and controlling subsequent outbreaks extremely challenging. Epidemiological evidence suggests that soft surfaces may be a relevant source of HuNoV due to the inability to effectively decontaminate. The objectives of this study were to: 1) review the current published literature on prevalence, transmission, and disinfection pertaining to HuNoV and surrogates with an emphasis on soft surfaces as fomites, 2) optimize a recovery method capable …

Investigating The Impact Of Novel Iron Oxide Nanoparticles On Legionella Pneumophila Biofilms And Trophic Interactions, Brennen Jenkins

All Theses

Microbial biofilms serve as the base of food webs and are important for nutrient cycling in aquatic ecosystems. Nanoparticles (NPs) that enter into these aquatic systems have the potential to settle and become trapped within biofilms. As NPs become further integrated into consumer products, understanding their fate and effects on aquatic ecosystems is of paramount importance. Previous studies from our lab show that gold NPs induce dispersal of Legionella pneumophila biofilms. NPs with platinum and iron oxide core chemistries also lead to similar dispersal events, however, silver core NPs do not seem to induce these events due to NP aggregation. …

A Genomewide Overexpression Screen Identifies Genes Involved In The Phosphatidylinositol 3-Kinase Pathway In The Human Protozoan Parasite Entamoeba Histolytica, Amrita B. Koushik, Brenda H. Welter, Michelle L. Rock, Lesly A. Temesvari

Publications

Entamoeba histolytica is a protozoan parasite that causes amoebic dysentery and liver abscess. E. histolytica relies on motility, phagocytosis, host cell adhesion, and proteolysis of extracellular matrix for virulence. In eukaryotic cells, these processes are mediated in part by phosphatidylinositol 3-kinase (PI3K) signaling. Thus, PI3K may be critical for virulence. We utilized a functional genomics approach to identify genes whose products may operate in the PI3K pathway in E. histolytica. We treated a population of trophozoites that were overexpressing genes from a cDNA library with a near-lethal dose of the PI3K inhibitor wortmannin. This screen was based on the rationale …

Validation Of Thermal Destruction Of Pathogenic Bacteria In Rendered Animal Products, Mary Hayes

All Dissertations

This study tested enumeration techniques for high fat food matrices and determined thermal death times in rendering animal products. Standard Class O phosphate/magnesium chloride dilution buffer series (Dilution Series A) and a modified (pre-warmed to 32oC) lecithin phosphate dilution buffer series (Dilution Series B) were used to enumerate a Salmonella cocktail from both poultry and beef rendering materials. Results of this study indicate use of a modified lecithin buffer did not improve Salmonella enumeration accuracy from rendering materials. Instead, the results suggested use of xylose lysine deoxycholate agar (XLD) with either buffer system accurately enumerated Salmonella from rendering materials. The …

Studies Of Molecular Mechanisms Of Cranberry Mediated Healthspan Promotion In Caenorhabditis Elegans, Sujay Guha

All Dissertations

Extensive studies have demonstrated the potent ability of many nutraceuticals to alleviate the symptoms of aging and stress. We found that cranberry extract (CBE) supplementation at an optimum concentration could prolong Caenorhabditis elegans (C. elegans) lifespan in a manner of daf-16 and osr-1 dependence. Considering that aging is a progressive degeneration of physiological functions, it is intriguing to know whether CBE consumption may delay the age-related degenerative changes in animals. Thus, we examined the effect of CBE consumption on healthspan in C. elegans populations with different ages and age-related disorders. Our results suggest that long-term CBE supplementation leads to a …