Digital Commons Network^™

The Development Of A New Water-Soluble Zinc Porphyrin, Zntpp--5ap, For Photodynamic Therapy, Kaylee Johnson

Honors Theses

This research focuses on synthesizing a new water-soluble porphyrin with a zinc core that can be used as a photosensitizing agent in photodynamic therapy. Photodynamic therapy is a process in which light is used to activate a photosensitizer to cause cell death. For this study, the porphyrin was synthesized by adding 5-amino-1-pentanol to the ZnTPPC. Once the porphyrin was synthesized it was purified using column chromatography through Sephadex LH-20 and G-50. The structure of the purified ZnTPP-5AP was then analyzed using nuclear magnetic resonance spectroscopy (NMR), infrared spectroscopy (IR), and ultraviolet-visible spectroscopy (UV-vis). Purity of the ZnTPP-5AP was tested using …

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, …

Oral Prevalence Of Akkermancia Muciniphila Among Pediatric And Adult Orthodontic And Non-Orthodontic Patients, Ching Shen

UNLV Theses, Dissertations, Professional Papers, and Capstones

Akkermansia muciniphila (AM) is one of many highly abundant intestinal microbes that influences homeostasis and metabolic disorders and may also play a role in oral disorders. However, there is little evidence regarding the oral prevalence of this organism. Based upon this lack of evidence, the primary goal of this project is to survey an existing saliva repository to determine the overall prevalence of this organism and any associations with demographic or patient characteristics (age, sex, body mass index, race/ethnicity, orthodontic therapy). Using an approved protocol, a total n = 141 pediatric samples from an existing saliva repository were screened using …

Impacts Of Bacterial Evolution On Host Lethality In Drosophila, Andrew Preston

College of Arts & Sciences Senior Honors Theses

Evolution is the process by which species change their genetic traits, such as the pathogenicity of bacteria, over time in response to changes in their environment. Although the genetic mechanisms underlying many evolutionary processes have been revealed, it is still not well understood how opportunistic pathogens, such as Pseudomonas aeruginosa, become virulent. The overall goal of this thesis is to test the Coincidental Evolution Hypothesis, which proposes that the virulence of opportunistic pathogens evolves coincidentally as a by-product of their interaction with their natural predators. I hypothesized that the virulence of ancestral Pseudomonas aeruginosa changes over time if it co-evolves …

From Micro To Macro: Examining Potential Microbiome Mediated Influences On Human Growth And Health Outcomes Through Breastfeeding And Antibiotic Exposures, Nicole K. Phillips

Electronic Thesis and Dissertation Repository

Human microbiome research has rapidly developed over the past two decades yet absent from most research is the composition and dynamics of microbiomes within human populations. Given the limitations in longitudinal studies which requires decades of repeated microbe taxonomic testing of a population sample, an alternative option is to examine microbiomes and their influences via proxies using pre-existing health datasets. This research demonstrates preliminary associations between presumed disrupted and supportive microbiomes dynamics proxied by antibiotic and breastmilk exposure respectively. Using health record data across the life span from approximately 500,000 U.K. participants, this research demonstrates variable altered growth and health …

The Antibacterial Efficacy Of Silver (I) Cyanoximates Against Streptococcus Mutans Ua159 Biofilm Growth And Infection In Galleria Mellonella Larvae, Jill Hughes

Honors Program Theses

Streptococcus mutans is the known etiological agent of dental caries. S. mutans’ virulence factors, namely biofilm formation and lactic acid fermentation, contribute to its pathogenic behavior within the oral cavity. Biofilms are thick, antibiotically resistant communities of bacteria that are much more difficult to treat than planktonic or free-floating bacteria. Continued misuse of antibiotics against dynamic communities, like biofilms, has led to increased research on non-antibiotic alternatives. Amongst these alternatives, there are silver and silver-based compounds. Silver is commonly incorporated into medicine due to its inhibitory and bactericidal effects and antibacterial properties. Silver (I) cyanoximates have demonstrated promising antibacterial activity …

Characterization Of The Clostridioides Difficile Glycosyl Hydrolase Ccsz, Brian Lowrance

Theses and Dissertations (Comprehensive)

Bacteria inhabit many of the harshest environments on Earth; persisting and thriving in conditions thought to be unsuitable for life. One common strategy to withstand these environments is the formation of a biofilm. Biofilm composition varies greatly, depending on the underlying community that produces it. Cellulose, a polymer consistently prevalent in biofilms, has been identified as a virulence factor in many pathogens and is suspected to be involved in pathogenesis by Clostridioides difficile. C. difficile is the #1 cause of hospital acquired diarrhea, which can range from mild to life-threatening infections. Biofilm formation is hypothesized to be involved in …

Inferring Adaptation In Social Microbes From Experimental Evolution Under Relaxed Selection, Tyler John Larsen

Arts & Sciences Electronic Theses and Dissertations

Microbes exist against a backdrop of other organisms, and the interactions between microbes have major consequences on their traits, their evolution, and their impact on the world. Microbial interactions and the adaptations that enable them are extremely diverse – they can unlock abilities beyond the reach of individual cells or lead to a population’s destruction, they can be temporary or permanent, they can be between genetically identical cells or different species entirely. The first chapter of this dissertation reviews microbial interactions and the related concept of the evolution of conflict and cooperation.To be certain a trait is an adaptation at …

The Role Of The Filifactor Alocis Hypothetical Protein Fa1654 In Oxidative Stress Resistance, Malissa Makaylia Mangar

Loma Linda University Electronic Theses, Dissertations & Projects

The survival/adaptation of Fillifactor alocis, a fastidious gram positive asaccharolytic anaerobe in the inflammatory environment of the periodontal pocket, requires an ability to overcome oxidative stress. Moreover, emerging observations suggest its pathogenic characteristics are highlighted by its capacity to survive in the oxidative-stress microenvironment of the periodontal pocket and its likely ability to modulate the microbial community dynamics. There is still a significant gap in our understanding of F. alocis mechanism of oxidative stress resistance and its impact on the virulence and pathogenicity of the microbial biofilm. The pathogenicity of F. alocis may be impacted by its response to oxidative …

Biomedical Applications Of Protein Films And Polymeric Nanomaterials, Sanjana Gopalakrishnan

Doctoral Dissertations

Biomaterials are widely applied for the diagnosis and treatment of numerous diseases. In addition to fulfilling specific biological functions, biomaterials must also be non-toxic, biocompatible, and sterilizable to be regarded as safe-for-use. Polymers are excellent candidates for fabricating functional biomaterials due to their wide availability and varied properties and may be natural or synthetic. Polymer precursors are fabricated into coatings, foams, scaffolds, gels, composites, and nanomaterials for several biomedical applications. This dissertation focuses on two types of polymeric biomaterials – protein-based materials and synthetic polymeric nanoparticles. Proteins are biopolymers that naturally occur with a variety of structural and functional properties. …

Consequences Of Biofilm Architecture On Vibrio Cholerae Ecology And Life History, Benjamin Ray Wucher

Dartmouth College Ph.D Dissertations

The diversity of microbes and the environments they inhabit are staggering. In many of these environments, bacteria have evolved to form sessile surface attached communities called biofilms. These biofilms have wide reaching impacts from importance in global carbon cycling, to persistent catheter infections, to biofouling and wastewater treatment. While many species of microbes form biofilms to survive in their environment, the architectures of these structures vary widely between organisms. Even though a great deal of work has been done to understand bacterial communities and their functions, little work has examined how the spatial aspects of biofilm architecture can affect the …

Characterization Of Antimicrobial Activity Of The Symbiotic Bacterium Xenorhabdus Szentirmaii, Miliya Ansad

Theses and Dissertations

Xenorhabdus species belonging to the Enterobacteriaceae family are gram negative bacteria that engage in symbiotic associations with the entomopathogenic soil dwelling nematodes of the family Steinernematidae. In this bacterium–nematode mutualistic interaction, both partners benefit from the association. By entering and perforating the insect gut and translocating to the body cavity of hemocoel, the nematodes gain access to the nutrient resource of the insect hemolymph. Xenorhabdus spp are released in the hemolymph in which they produce toxins and immunosuppressive compounds that kill the insect. During the infection Xenorhabdus spp grow to high cell density in the hemolymph. As the nematode invades …

Biomass Estimation Of Marine Biofilms On Plastic Surfaces, Kian Banihashemi, Fernando Javier Gil

Biological Sciences

Plastics have become a major source of marine pollution, which threatens food safety and quality, human health, and marine ecosystems. Due to the drastic negative effects of plastics in a marine environment, alternative biodegradable plastics are being generated that are more eco-friendly and have less environmental impact. Though some of these plastics are known to biodegrade, the process of degradation for bioplastics has not been heavily studied in a marine environment. This pilot project sought to both quantify the process of biodegradation and compare across different methods for effectiveness of biomass estimation, which serves as an indicator of biodegradation. Plastics …

Microbial Sociality In Biofilms, Swetha Kasetty

Dartmouth College Ph.D Dissertations

Biofilms are communities of microorganisms attached to surfaces through various self-secreted matrix materials. Biofilms are dynamic communities with extensive interactions between their residents. Microorganisms compete, cooperate, and communicate with each other in biofilms. These ecological interactions determine the emergence or loss of strains/species and are critical in the formation and proliferation of biofilms. Furthermore, most natural biofilms are formed by multiple microbial species and strains and these interactions within the biofilm dramatically influence community composition and structure over time. Microbial interactions also influence clinically relevant outcomes such as antibiotic resistance and host virulence. In this thesis we explore the potential …

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 …

Tales From The Tooth Worm: Reconstruction Of The Historic Oral Microbiome At The Milwaukee County Poor Farm Cemetery, Ashley Brennaman

Theses and Dissertations

Paleomicrobiological investigations of the human oral microbiome have primarily focused on samples of ancient origin, while fewer targeted studies of younger archaeological samples from the historic era have been conducted. However, the study of archaeological samples from the recent past, particularly the nineteenth century, can yield pertinent insights into the shifting temporal patterns of oral microbial diversity. For example, the sugar-rich diet associated with the Industrial Revolution of the mid-nineteenth century caused a shift in the composition of the oral microbiome towards a pathogenic state. Recent research has also demonstrated that the oral microbiomes derived from samples of modern and …

The Effect Of Cognitive Status And Residency On Oral Health In Patients With Dementia, Nicole Stephens

Dissertations & Theses (Open Access)

Poor oral health is a predictor of cognitive decline in elderly populations and has been shown to precede dementia. As cognitive decline progresses, patients are likely to move from the community into nursing facilities. We hypothesize that severity of dementia and residency type will impact the oral health of patients with dementia. Fifty-two participants of two dementia levels were recruited from the UTHealth Neurocognitive Disorders Center and two Houston-area nursing homes. A standardized oral health assessment, plaque index, and oral bacteria analysis determined participants’ oral health status. Further, data was collected on participants’ medical history, oral hygiene habits, dietary habits, …

Aggregatibacter Actinomycetemcomitans Exploits And Modulates The Immune Response By Human Neutrophils For Survival In The Anaerobic Environment., Hazel Ozuna

Electronic Theses and Dissertations

Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative facultative anaerobe and an opportunistic oral pathogen, strongly associated with localized periodontitis and other inflammatory diseases. Periodontitis is a chronic inflammation of the periodontium resulting from the inflammatory response of the host towards the dysbiotic microbial community present at the gingival crevice. The host immune response creates a hostile environment for microorganisms; therefore, it is important for Aa to be able to regulate the necessary genes to survive and thrive in such an environment. Aaexpresses several virulence factors such as a cytolethal distending toxin (Cdt), lipopolysaccharide (LPS) and leukotoxin A (LtxA), …

Antibacterial Activity Of Commiphora Molmol (Myrrha) Against The Periodontal Pathogen, Aggregatibacter Actinomycetemcomitans, Khalid Nafea Alharbi

Selected Full-Text Master Theses 2021-

The exogenous pathogen Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) is most frequently involved in periodontitis and other systemic diseases. The treatment of these infections involves antibiotic therapy with Amoxicillin being the most popular antibiotic against A. actinomycetemcomitans but now, the drug is not 100% effective due to the development of 0-84% antibiotic resistance. The present study aimed to determine antibacterial activity of Commiphora molmol (Myrrha) against the periodontal pathogen, Aggregatibacter actinomycetemcomitans. In detail, the strain LIU1239 of Aggregatibacter actinomycetemcomitans was used where the plasmid pVJT128 is used for transposon mutagenesis and the Escherichia coli strain MV10Nal (stock # LIU4). The …

Oral Microbiome And Its Effect On Respiratory Disease, Cole Pudwill

Biology and Microbiology Graduate Students Plan B Research Projects

The oral microbiome is composed of several different types of bacteria that can affect how our body operates. There are over 700 different bacteria living in our mouths. These bacteria can be helpful and harmful to our bodies, but they are synergistic in a way. There are several factors such as age, diet, smoking, and oral care that affect bacterial makeup. When there 10 is a significant difference, our immune system becomes weakened and respiratory disease set in. The immune system then works to return the microbiome back to homeostasis. When this fails, the diseases become chronic. Thus, the oral …

Effect Of Metal-Containing Nanoparticles On Bacterial Biofilms And On The Microbiome Of Girardia Tigrina, Azar Saikali

West Chester University Master’s Theses

Anthropogenically-produced nanoparticles are a form of nanotechnology being used in industries including food and textiles. Humans and livestock are frequently exposed to metal-containing nanoparticles (MCNPs), that have been washed into streams and rivers, have been deliberately used in food packaging as antimicrobials, preservatives or for supplementation. The animal microbiome, which consists of a diverse community of microorganisms, provides a number of benefits to the host in terms of nutrition availability, immune support, and can influence behavior. Biofilms of diverse microbes may cause detrimental effects, for instance by causing dental diseases in humans. However, the scientific community has not reached consensus …

Novel Microbe-Resistant Clay Dressing For Healing Burn Wounds, Kasey L. Rigby

Honors Undergraduate Theses

Every year, about 550,000 patients receive medical attention for minor and major burns in the United States.¹ In 2020, it was estimated that 11 million people worldwide suffered from burn injuries, with 150,000 of those burns being fatal.² Burns are among the most painful and debilitating recalcitrant wounds that can often turn terminal when infection occurs. The different grades for burns that we aim to treat are first, second, and third degrees.² Each burn type is susceptible to secondary infection that can be life threatening, and as a result, are extensively treated with antimicrobial agents.2 At present, …

Elucidation Of Novel And Established Campylobacter Species With Clinical And Agricultural Significance Through Phenotypic, Genotypic, And Taxonomic Investigation, Caoimhe Lynch

Theses

Campylobacter spp. are well-established human, veterinary and economic pathogens, with a broad host range spanning from terrestrial and marine mammalian, avian and reptilian hosts. The scope of the study includes novel and notorious species within the genus, with reference to zoonotic agents Campylobacter jejuni and Campylobacter coli - the leading cause of human bacterial gastroenteritis in the EU and Ireland, Campylobacter fetus that represents the most common campylobacter causing bacteraemia and two novel species isolated from pigs not described in the literature previously. C. jejuni and C. coli isolates (n = 350) recovered from broiler caecal and neck skin samples, …

Evaluate The Efficacy Of A Mixture Of Peroxyacetic Acid And H2o2 Against The Survival And Cross-Contamination Of The Salmonella Surrogate Enterococcus Faecium On Tomatoes During Triple-Wash, Corey Waitman Coe

Graduate Theses, Dissertations, and Problem Reports

Triple-wash with a mixture of peroxyacetic acid and H2O2 (SaniDate-5.0) during post-harvest processing of fresh produce has been recommended by West Virginia Small Farm Center to improve microbial safety. It has been well recognized that the washing of produce is more important for preventing cross-contamination than reducing foodborne pathogens. Furthermore, it may help improve public confidence in that the produce they obtain from locally grown farmers is safe for their consumption. determine the efficacy of SaniDate-5.0 for reducing the survival and preventing cross-contamination of the Salmonella surrogate Enterococcus faecium on tomatoes during triple-wash.

E. faecium ATCC-8459 (resistant to 100-ppm nalidixic-acid) …

Metabolic Heterogeneity And The Roles Of Cody And Ccpa In Central Metabolism And S. Aureus Biofilm Formation., Logan L. Bulock

Theses & Dissertations

Staphylococcus aureus is a metabolically versatile human pathogen, causing disease in many areas of the body. Its versatility can be attributed to the fact that it utilizes a variety of tools to adapt to many different environments, including toxins to scavenge from the host and multiple transporters to compete for its preferred carbon sources. S. aureus can also survive in harsh conditions through biofilm development, which are notoriously recalcitrant to antibiotics and immune defenses. Biofilms exhibit marked heterogeneity, with division of labor for production of matrix components and differential gene expression among various niches within the biofilm.

In this study, …

Examination Of The Association Between C - Reactive Protein(Crp) And Covid-19 Infection Severity And Length Of Hospitalization, Abdulahi Aremu Ayanwale

Open Access Theses & Dissertations

Chronic stress can lead to many systemic complications and low-grade systemic inflammation including increased levels of inflammatory cytokines, such as C-reactive protein (CRP). CRP is a marker of systemic inflammation and is associated with depression and perceived stress. Elevations can result in ineffective immune responses, thereby increasing the risk of complications and mortality from infections. Recent evidence suggests that uncontrolled inflammatory responses associated with COVID 19 are a major determinant of disease severity.  The COVID 19 is transmitted from one person to another through droplets from coughing, sneezing, talking, touching droplets on surfaces and contamination by hand-to-mouth routes. The mechanism …

Don't Sell Them Short, There's More To Bacterial Natural Products Than Antibiotics, Alison Clare Domzalski

Dissertations, Theses, and Capstone Projects

Recent genomic studies of microbiomes have revealed an overwhelming number of biosynthetic genes of unknown function. Most of these “cryptic” biosynthetic genes are not expressed in laboratory monocultures of individual microbes. Thus, there remains tremendous untapped potential for natural products discovery. Here we employ mixed microbial culture (MMC) as a simple yet powerful approach to awaken cryptic biosynthetic gene clusters. Our preliminary studies demonstrated that arrays of metabolites could be induced in MMCs upon environmental cues, such as surface adhesion. Using this system, we have screened, identified, and isolated bioactive bacterial metabolites, which were characterized structurally and biologically. Of the …

Comparing The Incidence And Prevalence Of Oral Microbial Pathogens Selenomonas Noxia And Streptococcus Mitis Within The Unlv-Sdm Clinical Patient Population, Namgu Kim

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Selenomonas noxia (SN) is a gram-negative, anaerobic bacteria, which contributes to development and progression of periodontal disease. Some evidence now suggests Streptococcus mitis (SM), a gram-positive, facultative bacterium contributing to the etiology of dental caries and periodontal disease, may also influence the prevalence of SN within subgingival complexes. Based upon the overall lack of prevalence data, the objective of this study was to evaluate presence of SN and SM using qPCR among saliva samples taken from pediatric, adult, and orthodontic dental school clinics.

Methods: This study involved a retrospective analysis of previously collected saliva samples from an existing biologic …

Isolating Oral Bacterial Species From A Single Donor Through A Multi-Step Detection Method, Khalid Al-Lakhen

Legacy Theses & Dissertations (2009 - 2024)

The human oral microbiome is one of the most complex microbiome communities in the human body and its role in maintaining health is not fully understood. Previous research shows that the transition from health to disease is accompanied by changes in community abundance and structure. To fully understand the symbiotic relationship formed between bacterial species that leads to the formation of a functional healthy biofilm structure, we must study the various structural relationships and subsequent molecular interactions among individual species within the biofilm. In this thesis, I have isolated a pure bacteria species from a single donor's dental plaque and …

Increasing The Frequency Of Periodic Spatial Disturbance Decreases Surface Attachment Protein Expression In Staphylococcus Aureus, Ivana M. Barraza

All HCAS Student Capstones, Theses, and Dissertations

Staphylococcus aureus is an opportunistic pathogen that can cause a variety of acute and chronic illnesses. The severity of these illnesses such as sepsis, necrotizing pneumonia, and toxic shock syndrome is measured through the virulence that S. aureus inflicts on its host. Methicillin-resistant S. aureus (MRSA) is commonly associated with secondary infections and is challenging to treat given the limited selection of antibiotics that are effective against it. Accordingly, novel approaches to reduce S. aureus pathogenicity are required. S. aureus regulates pathogenesis through a cell-to-cell communication system referred to as quorum sensing. Effective communication determines the production of two broad …