Microbiology Commons^™

Understanding Cellular Dynamics: Investigating A Yeast-Two Hybrid Protein-Protein Interaction, Riok3:Cse1l; Also By Investigating Trogocytosis Of Cd4+ T Cells From Rhog-/- Mice, Brittnee N. Crane

Graduate Student Theses, Dissertations, & Professional Papers

Rift Valley fever virus (RVFV) is a negative-sense virus that was first described in 1930 when it was isolated from sheep during an outbreak. In the last 25 years there has been a spread in the geographical range into the Middle East. The most susceptible animals are cattle, goats, sheep, and camels. The most overt symptom of livestock infection is that infected pregnant animals experience spontaneous abortion. Humans are susceptible as well and symptoms range from mild febrile illness to liver necrosis, blindness, hemorrhagic fever, and death. An important player in the cellular innate response to RVFV infections is the …

Investigating Birds As Dispersal Vectors Of Litylenchus Crenatae Subsp. Mccannii (Anguinidae), The Nematode Associated With Beech Leaf Disease, Spencer Rock Parkinson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Beech leaf disease (BLD) is an emerging forest pathogen primarily affecting American beech (Fagus grandifolia, Ehrh.) in North America and has been attributed to tree mortality of sapling sized trees within five to seven years of infection. Symptoms typically occur in regenerating American beech thickets sprouting from roots of trees killed by beech bark disease. Scientists first observed BLD in Ohio in 2012 and currently has spread to 15 states in the USA and one Canadian province. The nematode Litylenchus crenatae subsp. mccannii (Lcm) is highly associated with BLD symptoms, interveinal chlorosis and defoliation of leaves, and is currently …

Characterization Of Host Cell Specific Interactions During Spotted Fever Group Rickettsiae Infection, Emerson Towey

Graduate Theses, Dissertations, and Problem Reports (ETD)

Vector-borne diseases have been increasing over the past few years due to changes in climate and disturbances in the vectors’ natural environment. To mitigate the risks of these diseases, it is necessary to understand pathogen biology and how it interacts with a host to cause disease. Here we focus our attention on the tick-borne pathogen, Rickettsia rickettsii. R. rickettsii is a member of the spotted fever group (SFG) Rickettsiae and is the etiological agent of Rocky Mountain spotted fever (RMSF), a fatal human disease that is lacking an effective vaccine. Members of the bacterial genus Rickettsia are obligate intracellular endoparasites …

The Sewage Microbiome Dynamics Of Different Serving Neighborhoods In Charleston, Illinois, Sandra Chiamaka Okoye

Masters Theses

The complex microbial ecosystem within sewage systems holds significant implications for environmental and public health. Unlike studies on wastewater treatment plant microbiomes, upstream sewage systems have not been studied widely. This research investigated the dynamic sewage microbiome across diverse serving neighborhoods in Charleston, Illinois, encompassing residential, hospital, industrial, and university areas. Drawing upon recent advancements in microbiome research, the study aimed to unravel the spatial and temporal variations in microbial structures. Three times between June to December 2023 sewage samples were collected from manholes in the areas mentioned above. Community DNA was extracted and sequenced for the V4-V5 region of …

Causal Association Between Gut Microbiomes And Different Types Of Aneurysms: A Mendelian Randomization Study, Youjia Qiu, Yucheng Hou, Xingzhou Wei, Menghan Wang, Ziqian Yin, Minjia Xie, Aojie Duan, Chao Ma, Ke Si, Zhong Wang

Faculty, Staff and Student Publications

BACKGROUND: Previous studies suggests that gut microbiomes are associated with the formation and progression of aneurysms. However, the causal association between them remains unclear.

METHODS: A two-sample Mendelian randomization was conducted to investigate whether gut microbiomes have a causal effect on the risk of intracerebral aneurysm (IA), thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA), and aortic aneurysm (AA). Single nucleotide polymorphisms (SNPs) smaller than the locus-wide significance level (1 × 10

RESULTS: The phylum

CONCLUSION: Our MR analysis confirmed the causal association of specific gut microbiomes with AAA, and these microbiomes were considered as protective factors. Our result …

The Role Of Osaa Gene In Aspergillus Fumigatus Development, Secondary Metabolism And Virulence., Apoorva Dabholkar

Graduate Research Theses & Dissertations

Aspergillus fumigatus is the leading cause of aspergillosis, associated with high mortality rates, particularly in immunocompromised individuals. In search of novel genetic targets against aspergillosis, we studied the WOPR transcription factor OsaA. Deletion of the osaA gene resulted in colony growth reduction. Conidiation is also influenced by osaA; both osaA deletion and overexpression resulted in a decrease in spore production. Wild-type expression levels of osaA are necessary for expression of the conidiation regulatory genes brlA, abaA and wetA. In addition, osaA is necessary for normal cell wall integrity. Furthermore, deletion of osaA resulted in a reduction in the ability of …

Ascertaining A Biochemical Approach To Chlorophyll D Biosynthesis In Acaryochloris Spp., Rashmi Shivni

Graduate Research Theses & Dissertations

Photosynthesis is one of the most abundant metabolic systems on Earth, and specifically, oxygenic photosynthesis primed the planet for complex, multicellular life. The hallmark of modern oxygenic photosynthesis is the photopigment chlorophyll a found in nearly all oxygenic phototrophs as their primary photopigment in their photosynthesis pathways. There are also many organisms that tap into a variety of chlorophylls to extend the energetic limits of photosynthesis, which are largely found as accessory pigments. One genus of cyanobacteria, Acaryochloris, has garnered attention for the ability to undergo photosynthesis by harnessing the far-red part of the visible light spectrum using chlorophyll d …

Molecular Investigation Of Tick-Borne Pathogens In Feral Swine (Sus Scrofa) From Seven Us States, Sofiane Aiche

Masters Theses

Feral swine (Sus scrofa) have been proposed as part of the lifecycles of multiple tickborne pathogens (TBP). This is a result of the increase in feral swine populations and increased tick populations and geographic ranges. Few surveys exist on the TBP relevant to human and wildlife of feral swine in the US. The aim of this study is to investigate the prevalence of 10 TBP: Anaplasma spp., Borrelia spp., Cytauxzoon felis, Hepatozoon spp., Babesia spp., Mycoplasma spp., Trypanosoma cruzi, Toxoplasma gondii, Yersinia pestis, and Rickettsia spp. A total of 87 feral swine blood samples …

Sars-Cov-2 Immunogenicity Models Inform Novel Strategies That Can Improve Mrna Vaccines, Katherine S. Lee

Graduate Theses, Dissertations, and Problem Reports (ETD)

The onset of the 2020 COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, issued a call to action in the fields of biomedical science and public health to implement strategies to contain and protect against the viral threat. In record times, pharmaceutical companies produced antiviral therapies and novel mRNA vaccines that were approved by the FDA for human use. With time, these vaccines were able to assist in ending the pandemic. However, time also showed the limits of mRNA vaccine induced immunity. Despite antibody responses being initially robust, titers dramatically wane with time and are limited in cross-neutralizing ability. As …

Leveraging Bioinformatics To Understand Chlorophyll D Biosynthesis In Acaryochloris Spp., Dikshyant Gautam

Graduate Research Theses & Dissertations

Acaryochloris strains can adapt into far red region of the visible spectrum by utilizing its unique chlorophyll called chlorophyll d (Chl d). The genetic machinery behind Chl d has not been discovered yet. Biosynthetic pathway for other chlorophylls like chlorophyll a, chlorophyll b and chlorophyll f found in cyanobacteria are however well known. This research aims to understand the biosynthetic pathway responsible for chlorophyll d production. Bioinformatics approaches like comparative genomics, machine learning, and weighted gene co-expression network analysis (WGCNA) were central in this study to identify candidate genes and regulatory mechanisms potentially involved in chlorophyll d synthesis.

An important …

Dust-Driven Mechanism For Marine Particle Aggregation: Interactions Between Clay Minerals, Heterotrophic Bacteria And Organic Matter Influences Aggregation In Marine Systems, Vignesh Gokuladas Menon

Dartmouth College Master’s Theses

Atmospheric dust deposition plays a crucial role in marine biogeochemical cycles, yet mechanisms underlying its impact on particle dynamics remain unclear. This study investigates the synergistic interactions between marine heterotrophic bacteria and clay minerals in seawater, focusing on their effect on Transparent Exopolymer Particles (TEP) production and organoclay aggregation. Field experiments in the Gulf of Maine and laboratory roller tank studies were conducted using natural microbial communities and model heterotrophic bacterial strains (Alteromonas sp. EZ55, Marinobacter adhaerens HP15, and Sulfitobacter sp. NAS-14.1). Results demonstrate that clay exposure significantly enhances TEP production by bloom-associated heterotrophic bacteria, with increases up to …

Tetrodotoxin, Fungal Pathogen Infection, And Bacterial Microbiome Associations Are Variable In The Skin Microecosystems Of Two Taricha Newt Species, Talon B. Jost

EWU Masters Thesis Collection

Chytridiomycosis is an amphibian disease linked to population declines and species extinctions, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). While chytridiomycosis can result in host death, some amphibians are less susceptible to severe infections through intrinsic factors including host-associated skin microbes aiding defense through resource competition and antifungal metabolite production. Amphibians can also release toxins in response to stress cues to defend against disease, parasitism, and predation. Tetrodotoxin (TTX) is a potent low molecular weight neurotoxin found in genus Taricha, and despite a previously observed negative relationship between differential levels of TTX concentration and Bd infection presence within a …

Investigating The Role And Mechanism Of Host Cell Death In Porcine Reproductive And Respiratory Virus Infection, Michelle Steyn

Electronic Theses and Dissertations

No abstract provided.

Ecophysiology Of Bradyrhizobium Diazoefficiens Usda 110, Armaan Kaur Sandhu

Electronic Theses and Dissertations

With increasing demand for soybean, maximizing plant yield is important yiel is dependent on nitrogen availability, but nitrogen fertilizers can meet the plant's needs but have severe environmental impacts. An economically and environmentally sustainable approach is to enhance nitrogen availability through Biological Nitrogen Fixation by symbiotic rhizobia, Bradyrhizobium, an efficient nitrogen fixer for soybean. This symbiosis begins with attachment of rhizobia to legume roots. Root and rhizobia surface properties play a significant role in this attachment. Another major factor affecting root colonization is bacterial competition ability. There is a lack of knowledge on the role of bacterial surface properties, competition …

Scale And Habitat Effects On Measurement Of Streptomyces Biogeography And Biodiversity, Terilyn A. Stoflet

Cal Poly Humboldt theses and projects

Bacteria in the genus Streptomyces are detected in most soils around the world, as well as on and in seeds, plants, animals, insects and the wind. Currently, more than 700 valid species of Streptomyces have been identified worldwide. Streptomyces produce the majority of antibiotics, antivirals and antifungals, as well as important agricultural bioactive molecules due to their unique genetic capabilities. Their distinct genetic abilities allow them to produce an unlimited amount of biosynthetic gene clusters, or BGC’s. Although many compounds come from Streptomyces, scientists have not discovered the biogeographic patterns of this genus. The biogeography of Streptomyces is a …

Host-Defense Piscidin Peptides As Antibiotic Adjuvants Against Clostridioides Difficile, Adenrele Oludiran, Areej Malik, Andriana C. Zourou, Yonghan Wu, Steven P. Gross, Albert Siryapon, Asia Poudel, Kwincy Alleyne, Savion Adams, David S. Courson, Myriam L. Cotten, Erin B. Purcell

Chemistry & Biochemistry Faculty Publications

The spore-forming intestinal pathogen Clostridioides difficile causes multidrug resistant infection with a high rate of recurrence after treatment. Piscidins 1 (p1) and 3 (p3), cationic host defense peptides with micromolar cytotoxicity against C. difficile, sensitize C. difficile to clinically relevant antibiotics tested at sublethal concentrations. Both peptides bind to Cu²⁺ using an amino terminal copper and nickel binding motif. Here, we investigate the two peptides in the apo and holo states as antibiotic adjuvants against an epidemic strain of C. difficile. We find that the presence of the peptides leads to lower doses of …

Investigation Of L-Serine Synthesis And Transport As Stabilizing Feedback Mechanisms Within The Tsetse-Wigglesworthia Symbiosis, Ryan Phillips

Graduate Theses, Dissertations, and Problem Reports (ETD)

Tsetse flies (Glossina morsitans), which are the obligate vectors of Old-World trypanosomes (Trypanosoma spp.) that cause African trypanosomiasis, have a bacteriome that houses the intracellular endosymbiont Wigglesworthia glossinidia. The ancient coevolution of these species has led to the integration of Wigglesworthia metabolism into tsetse physiology and a subsequent reliance on nutrient exchange for maintaining the fitness of both partners. The establishment of this obligate mutualism has facilitated the emergence of feedback mechanisms that stabilize the symbiosis, such as that which involves the exchange of L-serine and B vitamins. The Gammaproteobacteria Wigglesworthia supplement B vitamins lacking …

The Role Of The Vibrio Cholerae Type Vi Secretion System During Kin Cell Interaction, Biofilm Formation And Priority Effects, Karen A. Castro

Dissertations and Theses

Vibrio cholerae’s Type VI secretion system (T6SS) is one of the arsenals used by the bacteria for its long-term survival in different environments, against a variety of opponents, and for its maintained pathogenicity in vulnerable regions of the world. Therefore, the more we understand about the activity of the T6SS, the closer we get to understanding its role in bacterial competition; inter-and-intra, and how this shapes a bacterial niche. Further, although the probiotic-like effect in the V. cholerae vaccine is described to work fast due to niche uptake hindering colonization of toxigenic strains, it is not yet clear if there …

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 …

Tim/Tam Receptors: A Potential Biomarker For Predicting Sensitivity To Zika Virus-Induced Oncolysis In Non-Small Cell Lung Cancers, Shankari Somasekar

Honors Undergraduate Theses

Non-small cell lung cancers (NSCLC) constitute 80-85% of lung cancers and are the leading cause of cancer-related deaths globally. The most common cause is prolonged smoking. Current treatment options for NSCLC include surgery, radiation, chemotherapy, targeted drug therapy, and immunotherapy. Although these medications are effective in the short term, patients often face issues of drug resistance and debilitating side effects with prolonged use. Currently, the use of Zika virus (ZIKV) is being researched as a possible alternative treatment for cancer, which minimizes side effects and the risk of drug resistance. TIM/TAM proteins are identified as the putative ZIKV receptors on …

Genetic And Biochemical Analysis Of Novel Borrelia Burgdorferi Genes Bb0244 And Bb0246, Christian J. Ruiz-Rodriguez

Honors Undergraduate Theses

As the cause of the most common vector-borne disease in the US, Borrelia burgdorferi continues to affect an estimated hundreds of thousands of patients each year. The spirochete boasts one of the most complex genomes in comparison to all other prokaryotes as it is fragmented across up to 21 different replicons. Moreover, the functions of a majority of the encoded genes remain unknown. Gene of unknown function, bb0244, along with putative co-transcribed genes bb0245, and bb0246 are hypothesized to be involved in the vital functions of cell division and cell wall biogenesis. B. burgdorferi lacking bb0244 demonstrate a significant growth …

Dysbiosis In Parkinson's Disease: A Meta-Analysis Of Gut Microbiota And Its Role In Gastrointestinal Dysfunction And Disease Progression, Ayan M. Siddiqui Mr.

Honors Undergraduate Theses

Parkinson's Disease (PD) is a neurodegenerative disorder characterized by motor and nonmotor symptoms, including gastrointestinal (GI) dysfunction. Symptoms such as constipation, bloating, and nausea often show early signs before the onset of motor symptoms. Recent research has suggested an essential role of the human gut microbiome and gut dysbiosis, an imbalance in gut microbiota composition, in the pathogenesis of PD. This thesis aims to assess the potential relationship between gut dysbiosis and PD by conducting a meta-analysis, focusing on differences in gut microbiota between PD patients and healthy controls and evaluating their implications for GI dysfunction and PD progression. The …

Invasion Of Superbugs: Cockroach-Driven Outbreak Of Multidrug-Resistant Enterobacter In An Icu, Jennifer Hanrahan, Nicholas Schouten, Steven H. Fyffe, Annette Jencson, Stephanie Stroever

Department of Medicine Faculty Publications

Objective: To describe factors in an outbreak of multidrug-resistant Enterobacter cloacae (MRE) in an intensive care unit (ICU) over a 20-month period including the likely contribution of cockroaches to the outbreak.

Design: This is a retrospective descriptive study.

Setting: ICU in an urban hospital.

Patients: All patients admitted to the ICU during the 20-month outbreak period were included in the study.

Interventions: Infection prevention interventions included contact isolation, hand hygiene, dedicated patient equipment, environmental cultures, and pest control.

Results: 25 patients were identified as being colonized or infected with MRE. Relatedness of the outbreak strain and strains found in cockroaches …

Salmonella Detection In Food Using A Hek-Htlr5 Reported Cell-Based Sensor, Esma Eser, Victoria A. Felton, Rishi Drolia, Arun K. Bhunia

Biological Sciences Faculty Publications

The development of a rapid, sensitive, specific method for detecting foodborne pathogens is paramount for supplying safe food to enhance public health safety. Despite the significant improvement in pathogen detection methods, key issues are still associated with rapid methods, such as distinguishing living cells from dead, the pathogenic potential or health risk of the analyte at the time of consumption, the detection limit, and the sample-to-result. Mammalian cell-based assays analyze pathogens’ interaction with host cells and are responsive only to live pathogens or active toxins. In this study, a human embryonic kidney (HEK293) cell line expressing Toll-Like Receptor 5 (TLR-5) …

Optimization Of An Immune Assay To Detect Binding Of Nod2 To Staphylococcus Aureus, Precious Mckenzie

All Student Theses and Dissertations

Staphylococcus aureus, a gram-positive, commensal bacterium, is the cause of a multitude of opportunistic diseases and infections. While S. aureus has evolved ways to escape innate immune responses in the host, the mechanisms are not fully understood. One area of active research involves mechanisms by which S. aureus avoids detection by Pattern Recognition Receptors (PRRs), such as Nuclear Oligomerization Domain 2 (NOD2), present on the surface of and inside innate immune cells. This study aimed to design and optimize an assay that can be utilized to investigate S. aureus components that contribute to the activation of NOD2 receptors. The …

Genomic Analysis And Antimicrobial Resistance Of Vibrio Parahaemolyticus Isolated From Seawater At Bang Pu Recreational Center, Samut Prakan Province, Thailand, Chinnawat Assana

Chulalongkorn University Theses and Dissertations (Chula ETD)

Vibrio parahaemolyticus is a foodborne bacterium that is widely distributed in worldwide marine environments including seawater, marine animals, and soils. This study aimed to identify genetic and antimicrobial resistance (AMR) of V. parahaemolyticus (n=46) isolated from seawater at Bang Pu recreational center, Samut Prakan province, Thailand. Genetic analysis from multi-locus sequence typing (MLST) classified the seawater isolates into 42 sequence types (STs) in total, with 29 being novel STs and 13 STs matched with previously reported strains in worldwide including clinical strains (ST356, ST303, STST320, and ST1919) and environmental strains (ST222, ST1083, ST1089, ST969, ST2965, ST2249 and ST233). A phylogenetic …

Investigating The Protein Interactome Of Escherichia Coli To Understand Metabolic Regulation When Proteins Bind: A Systems Biology Study., Shomeek Chowdhury

Theses and Dissertations

Proteins bind other proteins and work together as machines to perform many biological functions. Metabolic enzymes governing the life-sustaining metabolic reactions and therefore, metabolism are proteins which also binds other proteins. In this dissertation work, I have explored proteins when they interact with metabolic enzymes, play any role in regulating the cell’s metabolism. I study this phenomenon in Escherichia coli whose protein-protein interaction data is readily available in public databases with proper reference to the experimental study. Another good reason is the predictions we make in this computational study can be tested and validated in E. coli as it is …

Erwinia Amylovora Phage Therapy: Biocontrol Formulation, Receptor Identification, Resistance Mechanisms, Nassereldin Ibrahim

Theses and Dissertations (Comprehensive)

Fire blight is known as a disease of Rosaceae and it displays infection symptoms in about 200 species in 40 rosaceous genera. The most economically important crops that are affected by fire blight are apples and pears. Fire blight can cause severe outbreaks and a single fire blight outbreak can disrupt orchard production for years. The bacterium that causes this disease is indigenous in North America, and according to Statistics Canada, economic losses in apples and pears were valued at an estimated $4 million in 2005, which is approximately 5% of the total production. In addition, production costs can increase …