Microbiology Commons^™

Effects Of Plant Growth-Promoting Microorganisms On Microbial Community Dynamics And Plant Growth Responses Of Aeroponically Cultivated Spinach, Veronica Snow

All NMU Master's Theses

Regional food insecurity caused by the inability to use conventional farming techniques year-round in cold climates increases the need for access to quality, locally sourced, and affordable foods year-round. Shifting from a soil-based system to aeroponics can increase yields, as aeroponic systems are not weather-reliant and can operate year-round. Aeroponics, a subgroup of hydroponics, induces growth by misting nutrient-rich solutions onto the plant roots. These systems use space and water more efficiently and rely less on fertilizers and pesticides but are vulnerable to errors in nutrient application, power loss, and rapid pathogen spread. Adding Vermicompost (VCT) and plant growth-promoting microorganisms …

A Multi-Tiered Approach To Improving Vaccination: Adjuvanticity, Alternate Routes Of Delivery, And Science Communication, Haley Agnes Bridgewater

Boise State University Theses and Dissertations

Vaccines have been used to prevent infectious disease for over 200 years. While they are an incredible way to prevent loss of life, they can be improved upon. Researchers around the globe are working to improve the immune response and ultimately the protection provided by existing and new vaccines. In this dissertation, I investigate three ways to improve vaccine immune responses: using an adjuvant, using a prime-boost intramammary delivery route in cows, and using microneedle delivery route. Cholera toxin (CT) is a bacterial toxin that has a non-toxic B subunit (CTB) used as a vaccine adjuvant. However, little is known …

Phosphatase Activity And Structure Of The Spoiie Protein In Clostridioides Difficile, Kathryn Wootten

Biological Sciences Undergraduate Honors Theses

Clostridioides difficile is a major cause of severe gastrointestinal infections and diseases, particularly in healthcare settings. Because of its ability to produce infectious endospores by sporulation, the protein SpoIIE, which is known to play a role in the regulation of this process, is being explored as a potential therapeutic target. In order to gain better insight into the structure and function of this protein, a concentrated and purified sample of the protein must be obtained. The goal of this study was to determine the conditions that would yield the highest amount of SpoIIE. The density of the cultures of bacteria …

Serological Evaluation For Leptospirosis On Samples Received By The Connecticut Veterinary Medical Diagnostic Laboratory (Cvmdl), Hayden R. Samuels

Honors Scholar Theses

Leptospirosis is a globally distributed zoonotic disease caused by pathogenic species of Leptospira, motile spirochetes capable of infecting humans and animals. Transmission typically occurs through contact with water or soil contaminated by the urine of reservoirs or infected animals. Although leptospirosis is considered a neglected tropical disease, its geographic range is expanding due to climate change and urbanization. Surveillance remains limited in many regions, especially in the United States. This study aimed to assess the seroprevalence and serovar diversity of Leptospira exposure in a variety of domestic and wild animals submitted to the Connecticut Veterinary Medical Diagnostic Laboratory (CVMDL). …

Exploring The Antagonistic Polymicrobial Interaction Of Alcaligenes Faecalis With Prokaryotic And Eukaryotic Microorganisms, Aly Hargrave

Electronic Theses and Dissertations

Alcaligenes faecalis, a generally nonpathogenic, Gram-negative bacterium, has been observed by our laboratory to possess antagonistic activity against antimicrobial-resistant genera Staphylococcus, Candida, and Bacillus. This study focused on exploring the inhibition mechanism of A. faecalis against the three genera, with an emphasis on S. aureus. A library of A. faecalis transposon mutants was constructed and identified fourteen possible genetic factors linked to this inhibitory activity. Characterization of this inhibition indicated that A. faecalis suppressed S. aureus planktonic and biofilm growth via a contact-dependent mechanism, with pronounced effects during biofilm attachment phase. In a Caenorhabditis elegans …

Impact Of Shear Flow On Marine Biofilms Using Hyperspectral Imaging, Shantanu Mahesh Kore

All Theses

Various microbial communities in marine biofilms cause biofouling on submerged surfaces, posing challenges to marine industries. Despite their ecological and economic importance, biofilms' biomechanical and biochemical responses to hydrodynamic shear stress are insufficiently understood, particularly in dynamic flow conditions. To fill this gap, our study uses an innovative fiber-optic hyperspectral imaging (HSI) system and a supercontinuum laser source to examine marine biofilms' structure, composition, and detachment behavior at different shear stress levels.

To detect spectral and spatial heterogeneity in live biofilms without labeling, we created a custom imaging pipeline that captures reflectance spectra in the 600-850 nm range, targeting microbial …

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 …

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 …

Identifying Microbial Complexities And Control Strategies At Pre-Harvest Poultry Production, Tolulope Tiwa Ogundipe

Graduate Theses and Dissertations

While significant progress has been made in post-harvest control of Salmonella in the poultry industry, the development of effective pre-harvest intervention strategies remains critical for reducing foodborne pathogens. Environmental reservoirs such as poultry litter and drinking water systems (DWS) are potential harborage sites for Salmonella and other microbial communities. Understanding the microbiota of these environments, including biofilms within water lines, is essential to identifying factors contributing to Salmonella colonization and improving pre-harvest control approaches. This study aimed to evaluate the incidence and quantity of Salmonella in poultry litter and water lines, characterize the microbial populations in these environments, and assess …

The Impacts Of Management Practices On Industrial Hemp Chemistry, Physiology, And Microbiome Ecology., Allison Marie Rietman

Electronic Theses and Dissertations

Agroecology incorporates ecology and agronomy to inform crop management. Industrial hemp (Cannabis sativa L.) is a prime system to investigate agroecological questions because it has only recently been authorized for commercial cultivation and its sensitivity to biotic and abiotic stressors is unresolved. Here, I investigate how some conventional management choices, including the application of fungicide, plastic mulch, and irrigation, impact the physiology, chemistry, and microbial ecology of industrial hemp. Overall, I found that industrial hemp can be both resilient and resistant to these stressors, an important development for the industry. In Chapter II, I tested the impacts of fungicide application …

Sars-Cov-2 Modulates Pla2g2d/Pgd2 Signaling To Manipulate Host Immune Response To Increase Disease Severity., Dante L. Hamiel

Electronic Theses and Dissertations

Background: Previous studies suggested that SARS-CoV-2 infection could cause diverse immune and metabolic dysregulations, although the underlying mechanisms remain poorly understood. In addition, viruses may escape the immune response by modulating cellular metabolism, mitochondria, and protein functions indicating that immune or metabolic components may represent novel targets for anti-viral strategies. However, whether immune and metabolic disorders interact or affect each other waits to be determined. On the other hand, previous investigations identified the critical roles of a cell membrane-bound phospholipase PLA₂G2D and its downstream products PGD₂ in regulating the metabolism and inflammation in respiratory system. More importantly, …

Integration Of Multi-Omics Datasets Evaluating Structural And Functional Features Of The Gut Microbiome In People With Hiv (Pwh)., Aakarsha Vijayakumar Rao

Electronic Theses and Dissertations

Gut dysbiosis characterized by reduced abundance of beneficial butyrate-producing bacteria has been independently linked to HIV-1 infection and heavy alcohol drinking. Further, gut dysbiosis results in loss of gut barrier integrity, microbial translocation and host-specific systemic inflammation. Therefore, to evaluate the functional consequences of structural changes in the gut microbiome, integrated data analysis is imperative. In this dissertation, we perform integrated analyses using data from multi-omics platforms to examine the structural and functional features of the gut microbiome of PWH. Gut microbiome composition was evaluated by sequencing V4 region of 16S rDNA, concentrations of metabolites and host-specific immune markers were …

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, …