Microbiology Commons^™

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, 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, 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, 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, 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, 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, Huangen Ding

Faculty Publications

No abstract provided.

Advancing Biological Applications Through Microfluidic-Based Tool Development, K.M. Taufiqur Rahman

Electronic Theses and Dissertations

This research undertook an interdisciplinary approach, integrating bioengineering, microbiology, molecular biology, and systems biology to investigate bacterial dynamics behavior. Specifically, it delved into the development of microfluidic devices for biological applications such as bacterial cell counts, real-time observation of plant roots (here, specialized lectin-coated microbeads are used that mimic root characteristics), and soil microbe interactions. Furthermore, Next-Generation Sequencing and systems biology methodologies were employed to explore the intricate, multifaceted survival mechanisms of Escherichia coli persister population. Studying and quantifying persisters or testing for the existence of VBNC (viable but nonculturable) is challenging. These experiments require precise counts. It has been …

Role Of Interferon Induced Transmembrane Protein 3 (Ifitm3) And Neural Precursor Cell Expressed Developmentally Down Regulated Protein 4 (Nedd4) In Seneca Virus A (Sva) Replication, Shamiq Aftab

Electronic Theses and Dissertations

In this study, we studied the role of IFITM3 in SVA replication in vitro by silencing the endogenous IFITM3 in NCI-H1299 cells. An average of 1.94-fold increase in SVA VP2 expression and an average of 4.4-fold increase in supernatant virus titer was observed after 24h SVA isolate SD15-26 infection. We have indeed observed an increase in viral mRNA copies by an average of 5-fold in IFITM3 silenced NCI-H1299 cells at 8 hpi indicating that IFITM3 restricts SVA replication post virus attachment and entry. A positive correlation between interferon-alpha induced IFITM3 upregulation and reduced SVA replication was observed. To further confirm …

Do Duckweeds Adapt To Water And Microbes?, Ava M. Rose

Honors Theses and Capstones

Organisms in their home environment sometimes outperform transplanted individuals native to other areas, in a phenomenon termed local adaptation. While local adaptation is traditionally considered to be driven by the abiotic factors of an environment, scientists have recently increased consideration of biotic factors. Specifically, of interest to many is host-associated microbiomes, which can alter host trait expression. As the desire to commercialize microbiome treatments for agriculture and medicine grows, it is important to analyze the potential value of local microbiomes, which may be adapted to their hosts, or to which local hosts may have adapted. Using Lemna minor (duckweed) as …

Complete Genome Sequence Of Microbacterium Foliorum Phage Curie, A Podovirus Isolated From Soil In Spokane, Washington, Emma N. Horton, Kathryn T. Cook, Kyra G. Cronin, Avery T. Haag, Sierra M. Salter, Nicole A. Stojanovic, Zoe E. Fry, Brian M. Connolly, Rebekah F. Hare, Ann-Scott H. Ettinger, Marianne K. Poxleitner, Kirk Anders

Biology Faculty Scholarship

Bacteriophage Curie is a podovirus that infects Microbacterium foliorum. The Curie genome spans 16,810 bp, has 90 bp terminal inverted repeats, and includes 23 protein-coding genes. Its genome architecture resembles phage PineapplePizza and other phi29-like phages. Together, Curie and PineapplePizza form a new actinobacteriophage Cluster GI.

Persistence Of Wastewater-Associated Antibiotic Resistant Bacteria In River Microcosms, Aoife P. Mahaney

Theses and Dissertations

The spread of antibiotic-resistant bacteria (ARB) associated with wastewater is a significant environmental concern, but little is known about the persistence and proliferation of these organisms in receiving water bodies after discharge. To address this knowledge gap, we performed a series of microcosm experiments in which river water was amended with either untreated or treated wastewater, and the abundance of viable ciprofloxacin-, Bactrim-, and erythromycin-resistant bacteria was monitored for 72 hours.

Both types of wastewater amendments increased the initial abundance of ARB compared to microcosms containing only river water. The increase was greatest with untreated wastewater, but that effect decreased …

Developing Methods For Analysis Of Chiral Small Molecules And D-Amino Acid Containing Peptides, Joshua I. Putman

Chemistry & Biochemistry Dissertations - Archive

This dissertation covers the development of methods to analyze chiral small molecules and d-amino acid containing peptides. The first section covers the development of liquid chromatographic chiral screening approaches for newly synthesized chiral molecules. The next part of the dissertation covers methodologies for the analysis of d-amino acid containing peptides. Lastly the bacterial degradation of three commonly used pesticides by bacteria harvested from Colorado potato beetles (Leptinotarsa decemliniata) is presented.

Twelve new azole compounds and eleven racemic ethanolamine derivatives were synthesized. These twenty-three compounds were evaluated using eight chiral columns, four macrocylic glycopeptides, a cyclodextrin derivative …

Sun Damages And Preventative Measures For Keratinocyte Carcinomas, Alex Kandolin

Biology and Microbiology Graduate Students Plan B Research Projects

UV rays from the sun cause damage to our genomic DNA and in turn have the ability to cause cancer. Protection methods such as sunscreen have been used for many years, however, the introduction of polyphenols and topical creams have brought new hope to skin protection. Polyphenols are a new method using an internal approach that directly targets the damaged DNA using different mechanisms through food. When used in addition to sunscreen, the chances of skin cancer are greatly reduced. Additionally, but using topical cream such as 5-fluorouracil can be an approach to already existing lesions caused from UV radiation. …

Regulation Of Inflammatory Signaling By The Gut Microbiome, Caden Johnson

Biology and Microbiology Graduate Students Plan B Research Projects

The human gut contains trillions of bacteria that play a key role in gastric homeostasis. Commensal bacteria play a critical role in the formation of the gastrointestinal barrier that prevents invasion of other pathogenic bacteria and also serves as a secondary metabolism system that aids in the synthesis of dietary fibers into many essential nutrients such as vitamins, sugars, and especially short chain fatty acids (SCFAs) in the anaerobic conditions in the large intestine. These SCFAs assist in regulating immune tolerance to commensal bacteria of the gut and promote an anti-inflammatory state important to lowering the incidence of inflammatory disorders …

Treatment-Related Adverse Effects In African Cancer Patients: A Systematic Review, Gabriel T. Fagbenro

Biology and Microbiology Graduate Students Plan B Research Projects

Treatment associated with cancer comes with serious adverse effects which affect patients’ physiological functioning, worsen financial toxicity, reduce quality of life, and increased risk of treatment discontinuation. There is dearth of evidence on prevalence and pattern of side effects among African patients receiving cancer-directed therapies. Primary research studies reporting side effects of non-surgical interventions among patients in African countries were selected for review. The most prevalent side effects included nausea, vomiting, and loss of appetite (chemotherapy); radiation dermatitis and mucositis (radiation therapy); anaemia, neutropenia/febrile neutropenia, and thrombocytopenia (chemoradiation), and cardiotoxicity (immunotherapy). Oncologists need to pre-empt and provide necessary prophylactic and …

Fungal Activity In Fusarium Keratoplasticum Isolates With And Without Endohyphal Bacteria On Various Carbon Sources, Maya Brown

Honors College Theses

In recent years, the fungus Fusarium keratoplastic has been associated with failed sea turtle eggs. One fungal isolate collected from a failed egg collected on Wassaw Island, GA in 2020 contained endohyphal bacteria, bacteria living within the hyphae of the fungus. The type of endohyphal bacteria (EHB), as well as the relationship between the bacteria and fungal hosts, are currently unknown. Previous research on the same fungus and EHB, specifically Chitinophaga sp., discovered that EHB influenced the ability of the fungus to utilize carbon sources. Our research goal was to examine the metabolic relationship of Fusarium isolated from failed sea …

Investigating Antimicrobial Producing Bacteria Within The Soil, Adam Zwawi

A with Honors Projects

Genetic sequencing techniques used to identify soil antibiotic bacteria

Effect Of Dietary Flavonoids On Growth In Saccharomyces Cerevisiae, Vivian Rivera

Mahurin Honors College Capstone Experience/Thesis Projects

Plant foods contain a diversity of biologically active compounds called phytochemicals, produced by plant species as secondary metabolites. A phytochemical group known as flavonoids has received much scientific attention in recent times with respect to their antioxidative and anti-inflammatory roles. This investigation examined how quercetin and naringenin, the most common dietary flavonoids, affect growth potential of yeast under optimal and stress conditions (temperature, glucose, and oxidative stress). Using Saccharomyces cerevisiae as a model, a dose dependency effect of quercetin and naringenin was observed under optimal conditions when liquid cultures were treated with three different concentrations (75 μM, 150 μM, and …

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 …

Contributions Of The Replication Initiator Protein Dnaa To Physiology And Virulence Of The Lyme Disease Spirochete, Andrew Krusenstjerna

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Borrelia burgdorferi, the etiological agent of Lyme disease, is the most prevalent vector-borne disease in the United States. The spirochetal population is naturally maintained by consistently cycling between Ixodid ticks and small vertebrates. To survive within these diverse niches, B. burgdorferi has evolved a unique physiology and regulatory network to sense and respond to environmental fluxes. Replication is a hallmark of the Lyme spirochete’s enzootic life cycle, specifically at the nymphal tick-to-vertebrate interface. The mechanisms and regulatory schema for the basic cellular processes in B. burgdorferi, or indeed any member of the phylum spirochaetota, are largely unknown. The central hypothesis …

Role Of Autophagy-Related Genes In Lipid Transport For Efficient Replication Of Tombusviruses, Yuanrong Kang

Theses and Dissertations--Plant Pathology

Tombusviruses are positive-strand RNA viruses, which utilize numerous co-opted host factors and massive de-novo synthesized membrane resources to modify host membranes and form large viral replication organelles (VROs). Among plenty of host cellular processes, autophagy emerges as a potential membrane resource for VROs formation due to its ability to de-novo generate the double membrane structures, known as autophagosomes. Besides, as an important host defense pathway, autophagy is also a target for tombusviruses to prevent its antiviral activities. In this study, I identify the role of key autophagy related genes, Atg11, Atg8, and Atg2, which are involved in autophagosome formation, and …

Role Of Ph And Plant Age On The Selection Of Rhizobial Endophytes In Soybean Root Nodules, Cole Alexander Roman

Graduate Theses/Dissertations

Soybeans form symbiotic relationships with nitrogen-fixing bacteria in their root nodules to acquire most of their nitrogen requirement; nitrogen is often one of the limiting nutrients in the soil. Members of the Bradyrhizobium, Sinorhizobium, Mesorhizobium, and Rhizobium genera can nodulate soybeans. Bradyrhizobium is preferentially selected over other types of rhizobia in varying environmental conditions and is often found in acidic soils. Sinorhizobium is often identified in the root nodules of soybeans in neutral and alkaline soil. So far, the potential role of soil pH on the selection of rhizobial endophytes with soybean root nodules is unknown. Likewise, …

The Identification And Characterization Of Novel And Improved Antigens For Next-Generation Pertussis Vaccines, Gage Michael Pyles

Graduate Theses, Dissertations, and Problem Reports (ETD)

Whooping cough, or pertussis, is a highly infectious respiratory disease caused by infection with the Gram-negative bacterial pathogen Bordetella pertussis. Pertussis affects all age groups and populations; however, it is most severe in infants who are too young to receive vaccinations and remains a global health concern with more than­­­­ 200,000 cases reported globally in 2023. Vaccines against pertussis have been available in the United States since the 1940’s with the development and widespread use of whole cell pertussis vaccines. Following their introduction, the incidence of pertussis was controlled and limited to fewer than 5,000 cases per year. Despite …

Endogenous Glucocorticoid Signaling Is Required For Normal Macrophage Response To H. Pylori Infection, Stuti Khadka

Graduate Theses, Dissertations, and Problem Reports (ETD)

Gastric cancer is the fifth leading cause of cancer-related deaths worldwide, affecting millions of people. H. pylori is the strongest risk factor for gastric cancer, with about 90% of the cases strongly associated with H. pylori infection. Half of the world's population is infected with this bacterium. However, only a small subset of the infected population (1-3 %) go on to develop gastric cancer. Diagnosis of the disease at an early stage is the biggest challenge because of the widespread prevalence of H. pylori infection and a long asymptomatic phase before the advanced stages. Patients are left with limited treatment …

Examining The Role Of Microbial Communities In Soil Carbon Cycling Across Levels Of Complexity, Chansotheary Dang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Microorganisms provide the foundation for many ecosystem processes and are important drivers of carbon and nutrient cycling. The advancement of next generation sequencing has allowed researchers to lift open the lid on the ‘black box’ in microbial ecology. While previously unculturable microbes can now be characterized with the 16S rRNA gene, answering ‘who’s there?’ is only part of the challenge. Hidden inside the ‘black box’ remains the question, ‘who’s doing what?’. Recent development in trait-based methods like quantitative stable isotope probing (qSIP) equipped microbial ecologists with the tool to connect taxon-specific traits to ecosystem processes. Despite the growing body of …

Social Interactions And Spatial Structure Drive Community Assembly Of Bacterial Biofilm, Matthew C. Bond

Dartmouth College Ph.D Dissertations

Despite the critical nature which microbial communities play in the natural world and human civilization, the breadth of understanding remains shallow. Challenged by scale, high variability between environments, and extensive diversity, microbial ecologists strive to understand connections between a community’s structure and function, as well as the ecological and evolutionary mechanisms underlying observed natural patterning of communities. Biofilms are the predominate mode of growth for microbial communities—characterized by cellular attachment to a surface via a self-produced matrix and heterogeneous structure, often resulting in a primary growth front along the biofilm surface due to differential access to bulk nutrients (cite). This …

Batch Culture Models Of The Murine Gut Microbiome & The Impact Of Simple Dormancy On Dormancy-Capable Microorganisms Models, Ana C. Mendez

Mathematics Dissertations - Archive

The proposed mathematical biology research utilizes mathematical models to gain insight into biological systems. These systems of ordinary differential equations model diverse topics, ranging from gut microbiomes to harmful algal blooms. A complete stability analysis, supporting phase plane portraits, bifurcation diagrams, and numerical simulations will accompany the models presented. In Chapter 2, the murine gut microbiome is modeled to match laboratory experiments in the literature. In these experiments, mice eat plasmid-carrying “donor” bacteria and naturally carry plasmid-free “resident” bacteria in their gut. The models aim to capture the behavior of plasmids, donor bacteria, and resident bacteria. Chapter 3 explores dormancy …

Inflammation And Tumor Progression: The Differential Impact Of Saa In Breast Cancer Models, Daniel Wilhelm Olivier, Carla Eksteen, Manisha Du Plessis, Louis De Jager, Lize Engelbrecht, Nathaniel Wade Mcgregor, Preetha Shridas, Frederick C. De Beer, Willem J. S. De Villiers, Etheresia Pretorius, Anna-Mart Engelbrecht

Saha Cardiovascular Research Center Faculty Publications

Background: Previous research has shown that the Serum Amyloid A (SAA) protein family is intricately involved in inflammatory signaling and various disease pathologies. We have previously demonstrated that SAA is associated with increased colitis disease severity and the promotion of tumorigenesis. However, the specific role of SAA proteins in breast cancer pathology remains unclear. Therefore, we investigated the role of systemic SAA1 and SAA2 (SAA1/2) in a triple-negative breast cancer mouse model.

Methods: Syngeneic breast tumors were established in wild-type mice, and mice lacking the SAA1/2 (SAADKO). Subsequently, tumor volume was monitored, species survival determined, the inflammatory profiles of mice …

Poor Water Quality As A Trigger Of Harmful Algal Blooms In Lake Manzala, Mohammed A. Hussein, Alaa Eldin Eissa, Reham M. Eltarabily, Mohamed F. Abdelghany, Mahmoud A. Elnakeeb, Eman M. Ismail, Reham H. Ragab, Amina A. Dessouki

Mansoura Veterinary Medical Journal

Objective: The current study aimed to assess the direct effects of poor water quality on the eruption of heavy harmful algal blooms and to assess the physicochemical properties of water in Lake Manzala, as well as the molecular identification of the retrieved green algae.

Procedures: Subsurface water samples were collected from three different sites in September 2023 for water quality assessment. Moreover, morphological and molecular identification of suspected harmful algae is the most reliable diagnostic tool for this eruption.

Results: This study was conducted in the northern and northeastern regions of Lake Manzala. These regions receive large amounts of municipal, …