Friends With Benefits: How Picking The Right Partner Pays Off,
2024
University of Texas at Arlington
Friends With Benefits: How Picking The Right Partner Pays Off, Patrick T. Stillson
Biology Dissertations - Archive
Animals are highly dependent on microbial symbionts for nutrient supplementation, parasite protection, toxin resistance, and more. While these microbes are important, these associations have the potential to shift from mutualistic to parasitic across environments and over time. Eight insect families from the hemipteran infraorder Pentatomomorpha have evolved a highly specialized relationship with bacteria in the genus Caballeronia. The symbiont is a free-living microbe, acquired from the environment each generation during early host development. By manipulating environmental conditions, I used the bug-Caballeronia model 1) to investigate whether symbionts with greater growth rates at high temperatures prevent hosts from experiencing …
Role Of Extracytoplasmic Function (Ecf) Sigma Factors In The Survival And Symbiosis Of Nitrogen-Fixing Bradyrhizobium Under Desiccation Stress And Comparative Analysis Of Desiccation-Tolerant Rhizobial Isolates,
2024
University of Texas at Arlington
Role Of Extracytoplasmic Function (Ecf) Sigma Factors In The Survival And Symbiosis Of Nitrogen-Fixing Bradyrhizobium Under Desiccation Stress And Comparative Analysis Of Desiccation-Tolerant Rhizobial Isolates, Mohammad Kamruzzaman
Biology Dissertations - Archive
Rhizobia are soil bacteria that facilitate biological nitrogen fixation (BNF) through a symbiotic relationship with legumes such as soybeans. As an eco-friendly alternative to chemical nitrogen fertilizers, rhizobial inoculants can enhance plant growth and yield. However, they face various stresses, including drought (i.e., desiccation). Rhizobia can manage desiccation stress by accumulating trehalose, a disaccharide produced by genes such as otsA, otsB, and treS. Extracytoplasmic function (ECF) sigma factors sense external signals and regulate these desiccation-related genes during the stress. Previous studies have highlighted the importance of EcfG in response to desiccation stress and symbiosis. Based on the protein sequence …
Temporal Distribution Of Potential Waterborne Pathogens In Sequiota Spring,
2024
Missouri State University
Temporal Distribution Of Potential Waterborne Pathogens In Sequiota Spring, William J. Durstock
Graduate Theses/Dissertations
Waterborne pathogens from human fecal matter pose a significant health risk in karst environments, where domestic wastewater can easily be transferred to the shallow groundwater system via old, leaky septic tanks and damaged sewer lines. This study monitored fecal indicator bacteria (FIB) and potential pathogens in Sequiota Spring located in the karst region of southwest Missouri, using Microbial Source Tracking (MST) and Illumina DNA sequencing of bacterial 16S rRNA genes. MST identified high levels of human fecal indicator bacteria (HFIB) (up to 110,000 cells/L) in July 2020. By June 2022, HFIB levels had dropped significantly (55-fold reduction) after the City …
Effects Of Subchronic Oral Pfos Exposure Via Drinking Water On Gut Microbiota Composition,
2024
Missouri State University
Effects Of Subchronic Oral Pfos Exposure Via Drinking Water On Gut Microbiota Composition, Emma Ann Loder
Graduate Theses/Dissertations
Perfluorooctanesulfonic acid (PFOS) has been phased out of production in the United States, but because of its resistance to degradation and its persistence in the environment, PFOS can be found in drinking water across America. Oral exposure to PFOS has been linked to adverse developmental, immunological, hepatic, and endocrine health. Oral PFOS exposure may alter the gut microbiota and cause dysbiosis, which is implicated in the pathology of inflammatory diseases like Crohn’s disease, diabetes, and ulcerative colitis. The goal of the study was to investigate the effects of subchronic oral PFOS exposure on the composition of the gut microbiota. Adult …
Patterns Of Epiphytic Bacterial Growth On Flower Surfaces: Relationships With Flower Longevity And Environmental Factors,
2024
Missouri State University
Patterns Of Epiphytic Bacterial Growth On Flower Surfaces: Relationships With Flower Longevity And Environmental Factors, Rita Nkem Afagwu
Graduate Theses/Dissertations
Flowers host diverse communities of epiphytic bacteria, which can impact floral functions, pollinator interactions, and overall plant fitness. However, little is known about how the abundance of these bacteria change as flowers age, and how these shifts may correlate with floral longevity. In this study I investigate the change in bacterial abundance across the lifespan of a flower from anthesis (opening of bud to flower) to senescence (wilting of flower) and to explore the potential implications for floral longevity. We tracked the age of the flowers by determining the average age to senescence in flowers of 8 plant species over …
How Environmental Variation Affects Bumblebee Cognition And The Gut Microbiome,
2024
Missouri State University
How Environmental Variation Affects Bumblebee Cognition And The Gut Microbiome, Parker Madison Campbell
Graduate Theses/Dissertations
This master's thesis examines the influence of environmental variables on cognitive processes in Bombus impatiens, focusing on the effects of ingested microbial communities on gut microbiota and their subsequent impact on associative color learning. The study implemented controlled feeding trials with isolated microbe species (Candida bombi, Metschnikowia reukaufii, Lactobacillus micheneri and a control with no microbes) to analyze shifts in gut microbial composition in foraging bees. Results indicated minor alterations in the microbial profiles of bees, yet no statistically significant correlation was found between these modifications and variations in learning or memory performance. Furthermore, the study assessed the impact of …
Antibiotic Resistance In A Coastal River In Mississippi, Usa – Potential Drivers,
2024
The University of Southern Mississippi
Antibiotic Resistance In A Coastal River In Mississippi, Usa – Potential Drivers, Shuo Shen, Wei Wu, Eric A. Saillant, Darrell Jay Grimes
Gulf and Caribbean Research
Wastewater treatment plants (WWTPs) are major sources of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in water bodies. Most studies on the impact of WWTPs on antibiotic resistance have focused on freshwater systems, with little information on coastal and estuarine waters with variable salinity. This study monitored seasonal levels of ARGs at the effluent and downstream of the Pascagoula— Moss Point WWTP in the lower Pascagoula River, a coastal river in southeastern Mississippi, USA. Surface water samples were collected seasonally at upstream, outflow, and 3 downstream sites from February to November 2016. Bacterial resistance to sulfamethazine, tetracycline, and …
Why Should Early-Career Scientists Publish In Society Journals,
2024
Clemson University
Why Should Early-Career Scientists Publish In Society Journals, Stephen K. Dolan, Lori D. Banks, Wenqi Yu
Molecular Biosciences Faculty Publications
In this editorial, written by early-career scientists, we advocate for the invaluable role of society journals in our scientific community. By choosing to support these journals as authors, peer reviewers, and as editors, we can reinforce our academic growth and benefit from their re-investment back into the scientific ecosystem. Considering the numerous clear merits of this system for future generations of microbiologists and more broadly, society, we argue that early-career researchers should publish our high-quality research in society journals to shape the future of science and scientific publishing landscape.
The Inaugural Mbio Junior Editorial Board—Lessons Learned And The Path Forward Toward Improving The Peer Review Process,
2024
University of Cape Coast
The Inaugural Mbio Junior Editorial Board—Lessons Learned And The Path Forward Toward Improving The Peer Review Process, Cynthia Ayefoumi Adinortey, Stephen K. Dolan, Sarah Doore, Rebeccah Lijek, Diana Priscila Pires, Wenqi Yu, Elizabeth B. Draganova, Lennart Schada Von Borzyskowski
Molecular Biosciences Faculty Publications
The inaugural Junior Editorial Board (JEB) of mBio consisted of 64 early-career researchers active from 2022 to 2023. The goal of the JEB was to train early-career researchers in the art of peer review under the guidance of experienced editors. JEB members gained hands-on experience in peer review by participating in modules detailing the publishing process through the lenses of the journal, editor, and reviewer. Ultimately, JEB members applied this new knowledge by reviewing mBio manuscripts. Here, we summarize the background, the mission, and the achievements of the first mBio JEB. We also include possible trajectories for the future editions …
Revolutionizing Our Understanding Of Specific Platelet-Pathogen Interactions,
2024
University of Kentucky
Revolutionizing Our Understanding Of Specific Platelet-Pathogen Interactions, Hammodah Rawhi Hammodah Alfar
Theses and Dissertations--Molecular and Cellular Biochemistry
Aside from their classical role in maintaining hemostasis, platelets are considered first-line vascular guardians that influence both the innate and adaptive immune systems. This is mediated by either direct interactions with immune cells or through the release of pre-stored cytokines and chemokines upon interacting with pathogens such as viruses. While this establishes platelets as potential players in the response to pathogens, it remains unclear what platelets can do with pathogens and how important that is to immune responses, especially against viruses. Most systemic viremias, such as HIV-1, present with mild thrombocytopenia, which is mediated through several mechanisms such as a …
Metal-Ion Doped Borate Bioactive Glasses- A Novel Direction In Minimizing Nosocomial Infections And Antibiotic Resistance,
2024
Missouri University of Science and Technology
Metal-Ion Doped Borate Bioactive Glasses- A Novel Direction In Minimizing Nosocomial Infections And Antibiotic Resistance, Sarah Fakher
Masters Theses
"Nosocomial infections represent a formidable challenge and induce a substantial burden on patients and healthcare systems. These infections result from the interaction of numerous pathogenic microorganisms, particularly bacteria, and lead to increased morbidity, mortality, and healthcare costs. Extensive research has been carried out to devise innovative solutions, mainly focusing on antimicrobial natural and synthetic substances. However, the proclivity of bacterial strains to form biofilms complicates treatment and elevates antibiotic resistance, prompting research into pioneering more effective and versatile antibacterial strategies. Borate bioactive glasses (BBGs) are the latest, remarkable classes of biomaterials with a wide array of medical applications, owing to …
In Vitro Assessment Of The Anti-Biofilm Effectiveness Of Copper And Zinc Enhanced Borate Bioactive Glass Using Processed Microscopic Images,
2024
Missouri University of Science and Technology
In Vitro Assessment Of The Anti-Biofilm Effectiveness Of Copper And Zinc Enhanced Borate Bioactive Glass Using Processed Microscopic Images, Sarah Fakher, David J. Westenberg
Biological Sciences Faculty Research & Creative Works
The escalating burden of nosocomial infections presents a formidable challenge to healthcare systems worldwide, leading to increased morbidity, prolonged hospital stays, and elevated healthcare costs. These infections are often resistant to conventional antibiotic therapies due to their association with biofilms which contribute to the persistence and resistance of pathogens. In addressing the challenge of biofilm-associated nosocomial infections, borate bioactive glasses (BBGs) have emerged as promising biomaterials. Doping these glasses with antimicrobial metals could potentially harness their antibacterial properties to prevent biofilm formation. This study undertakes a rigorous evaluation of the anti-biofilm efficacy of copper and zinc-doped BBGs by employing processed …
Screening And Analysis Of The Urobiome For The Production Of Antimicrobial Peptides To Target Uropathogenic Escherichia Coli,
2024
Department of Biological Sciences, Munster Technological University, Cork, Ireland
Screening And Analysis Of The Urobiome For The Production Of Antimicrobial Peptides To Target Uropathogenic Escherichia Coli, Jennifer Jones
Theses
Urobiome research is currently at a nascent stage, due to a previously incorrect assumption that the bladder is a sterile environment. Improvements in bacterial culturing and DNA sequencing techniques have revealed a diverse resident bacterial community within the urinary tract (urobiome). As global incidences of multidrug- resistant urinary tract infections (UTIs) continue to increase, so too does the demand for novel antimicrobial therapies. Due to its relatively understudied nature, the urobiome represents a reservoir that could be mined as a potential source of novel antimicrobial compounds (e.g., bacteriocins). The aim of this thesis was to identify urobiome bacteriocins that could …
Investigating The Development Of Alcohol Tolerance In The Eskape Pathogens,
2024
West Chester University
Investigating The Development Of Alcohol Tolerance In The Eskape Pathogens, Hannah Durkee
West Chester University Master’s Theses
Antiseptics and disinfectants are used globally to kill or inhibit the growth of bacteria to prevent infection. Considering the well-documented development of antibiotic resistance, the potential for evolved tolerance to alcohol-based antimicrobial agents raises concern. The ESKAPE bacterial pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) are a major cause of healthcare-associated mortality and present a threat to public health due to the progression of multi-drug resistance. We conducted an experiment to determine if the ESKAPE pathogens develop an increased tolerance to ethanol upon repeated exposure by selecting for survivors after a …
Characterization Of Serx: A Putative Periplasmic Binding Protein In A Selenate Respiring Bacteria,
2024
Colby College
Characterization Of Serx: A Putative Periplasmic Binding Protein In A Selenate Respiring Bacteria, Henry Jacques, Susan E. Childers
Honors Theses
A selenate respiring bacterium, Dechloromonas sp. A34, was isolated from a seleniferous mining site in southeastern Idaho. A34 was of interest due to its ability to respire up to 20 mM selenate, the highest concentration tested. The strain has been proposed to represent a new species of bacteria within the Dechloromonas genera, with the prospective name Dechloromonas selenatirespirans (manuscript in preparation). Our research presents characterization of a putative periplasmic binding protein found within an operon that contains genes encoding a putative selenate reductase. The gene, named serX (selenate reductase gene X), is 855 base pairs and encodes a putative …
A Comparison Of Adenosine Triphosphate With Other Metrics Of Microbial Biomass In A Gradient From The North Atlantic To The Chesapeake Bay,
2024
Old Dominion University
A Comparison Of Adenosine Triphosphate With Other Metrics Of Microbial Biomass In A Gradient From The North Atlantic To The Chesapeake Bay, Alexander B. Bochdansky, Amber A. Beecher, Joshua R. Calderon, Alison N. Stouffer, Nyjaee N. Washington
OES Faculty Publications
A new, simplified protocol for determining particulate adenosine triphosphate (ATP) levels allows for the assessment of microbial biomass distribution in aquatic systems at a high temporal and spatial resolution. A comparison of ATP data with related variables, such as particulate carbon, nitrogen, chlorophyll, and turbidity in pelagic samples, yielded significant and strong correlations in a gradient from the tributaries of the Chesapeake Bay (sigma-t = 8) to the open North Atlantic (sigma-t = 29). Correlations varied between ATP and biomass depending on the microscopic method employed. Despite the much greater effort involved, biomass determined by microscopy correlated poorly with other …
Parametric Study Of The Effect Of Increased Magnetic Field Exposure On Microalgae Chlorella Vulgaris Growth And Bioactive Compound Production,
2024
Old Dominion University
Parametric Study Of The Effect Of Increased Magnetic Field Exposure On Microalgae Chlorella Vulgaris Growth And Bioactive Compound Production, Sharanabasaweshwara Asundi, Sanurag Rout, Simone Stephen, Sanghamitra Khandual, Sandipan Dutta, Sandeep Kumar
Mechanical & Aerospace Engineering Faculty Publications
This parametric study aimed to analyze the effects of increased magnetic field exposure (MFE) on the growth and production of the bioactive compounds of Chlorella (C.) vulgaris. With the intent of studying the effect of an increased MFE, the magnetic field typically experienced by life on Earth was amplified by an order of magnitude. In the increased-MFE environment, six treatments of C. vulgaris with two repetitions for each treatment were exposed to a magnetic field of 5 Gauss (500 µT) about each axis, which was generated in a state-of-the-art Helmholtz cage. The treatments and the control were characterized by the …
Reiq-Mediated Alarmone Signalling Regulates Growth, Stress-Induced Biofilm Formation And Spore Accumulation In Clostridioides Difficile,
2024
Old Dominion University
Reiq-Mediated Alarmone Signalling Regulates Growth, Stress-Induced Biofilm Formation And Spore Accumulation In Clostridioides Difficile, Areej Malik, Adenrele Oludiran, Asia Poudel, Orlando Berumen Alvarez, Charles Woodward, Erin B. Purcell
Chemistry & Biochemistry Faculty Publications
The bacterial stringent response (SR) is a conserved transcriptional reprogramming pathway mediated by the nucleotide signalling alarmones, (pp)pGpp. The SR has been implicated in antibiotic survival in Clostridioides difficile, a biofilm- and spore-forming pathogen that causes resilient, highly recurrent C. difficile infections. The role of the SR in other processes and the effectors by which it regulates C. difficile physiology are unknown. C. difficile RelQ is a clostridial alarmone synthetase. Deletion of relQ dysregulates C. difficile growth in unstressed conditions, affects susceptibility to antibiotic and oxidative stressors and drastically reduces biofilm formation. While wild-type C. difficile displays increased biofilm …
Multiple Variables Influence The Finely Calibrated Antioxidant Defenses Of Clostridioides Difficile,
2024
Old Dominion University
Multiple Variables Influence The Finely Calibrated Antioxidant Defenses Of Clostridioides Difficile, Erin B. Purcell
Chemistry & Biochemistry Faculty Publications
The obligate anaerobe Clostridioides difficile encodes multiple reductases to detoxify molecular oxygen and reactive oxygen species. Caulat and colleagues have characterized the activity and regulation of four such reductases (L. C. Caulat, A. Lotoux, M. C. Martins, N. Kint, et al., mBio 15:e01591-24, 2024, https://doi.org/10.1128/mbio.01591-24). Each proved critical for clostridial survival in a different range of oxygen concentrations; together, they ameliorate a broad range of oxidative stress levels. Moreover, two previously uncharacterized regulators were found to control reductase gene expression in response to oxidative stress. The genetic repressor Rex and the reductase FdpF are both sensitive to the NAP …
Iron–Sulfur Cluster Assembly Scaffold Protein Iscu Is Required For Activation Of Ferric Uptake Regulator (Fur) In Escherichia Coli,
2024
Louisiana State University
Iron–Sulfur Cluster Assembly Scaffold Protein Iscu Is Required For Activation Of Ferric Uptake Regulator (Fur) In Escherichia Coli, Huangen Ding
Faculty Publications
No abstract provided.
