Microbiology Commons^™

Exploring The Dynamics Of Bacterial Populations In The Gut Microbiota, Shaikh Obaidullah

Biology and Medicine Through Mathematics Conference

No abstract provided.

Helices In Fluids And Their Applications, Eva M. Strawbridge

Biology and Medicine Through Mathematics Conference

No abstract provided.

Adenoviral-Vectored Epigraph Vaccine Elicits Robust, Durable, And Protective Immunity Against H3 Influenza A Virus In Swine, Erika M. Petro-Turnquist, Matthew J. Pekarek, Nicholas Jeanjaquet, Cedric Wooledge, David J. Steffen, Hiep Vu, Eric A. Weaver

Nebraska Center for Virology: Faculty Publications

Current methods of vaccination against swine Influenza A Virus (IAV-S) in pigs are infrequently updated, induce strain-specific responses, and have a limited duration of protection. Here, we characterize the onset and duration of adaptive immune responses after vaccination with an adenoviral-vectored Epigraph vaccine. In this longitudinal study we observed robust and durable antibody responses that remained above protective titers six months after vaccination. We further identified stable levels of antigen-specific T cell responses that remained detectable in the absence of antigen stimulation. Antibody isotyping revealed robust class switching from IgM to IgG induced by Epigraph vaccination, while the commercial comparator …

Single-Molecule Super-Resolution Imaging Of Geobacter Sulfurreducens Under Anaerobic Conditions, Ziyi Hu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Geobacter sulfurreducens are anaerobic bacteria capable of making electrical contacts with other organisms and extracellular electron acceptors. The challenge of imaging live Geobacter bacteria is maintaining anaerobic conditions during the imaging process. In this thesis, we augment a single-molecule localization microscope (SMLM) with a home-built anaerobic imaging chamber and use constant argon bubbling to maintain oxygen-free imaging conditions. To validate the imaging protocol, we use the transient binding of Nile red to resolve the spherical morphology of lipid-coated glass spheres with nanoscale resolution. However, when imaging Geobacter, the distribution of Nile red localizations is non-uniform, both between different cells …

Characterization Of Lps As A Virulence Factor In Burkholderia Cepacia During Plant And Human Infection, Jack Klahr, Elizabeth Danka

Biology Senior Theses

Burkholderia cepacia is a gram-negative bacterium first characterized as the causative agent of sour skin in onion crops. More recently, B. cepacia has become a clinical concern as an opportunistic pathogen that can colonize the upper respiratory tract of cystic fibrosis patients and increase mortality in these patients. Infection is exacerbated by the intrinsic resistance to antibiotics found in this genus of organisms. Additional virulence factors help the bacteria persist in the host during infection. However, few of these factors have been described. In this work, we characterized a putative virulence factor that was first identified through an onion infection …

The Effects Of Aloe Vera On The Human Gut Microbiome, Samantha Leon

Honors Theses

The human gut microbiome is a diverse community of bacteria influenced by multiple factors including host age, geographical location, and diet. This study observed the effects of aloe vera juice on the human gut microbiome. Fecal samples were taken every two weeks over a period of one year; the subject consumed aloe vera juice in alternating cycles of consumption “on” and abstaining “off” with each cycle lasting for eight weeks. The bacterial community in each sample was characterized using 16S rRNA gene sequencing. Sequences were identified and their relative abundances were used to look for patterns distinguishing “on” and “off” …

An Analysis Of The Sensory Characteristics And Microbial Constituents Of Kefir, Katherine Quay Robinson

Honors Theses

Kefir is a fermented beverage produced using sugar water or milk, kefir grains, either water kefir grains or milk kefir grains, respectively, and microbial aggregates consisting of diverse bacteria and yeasts. As kefir and fermented beverages in general are increasing in popularity, research related to optimal sensory characteristics and consumer-approval is vital. Desirable sensory characteristics for kefir beverages include low sour taste/aroma, high sweetness, carbonation, and high viscosity (Surja et al., 2019; Margareth et al., 2020). Production methods of kefir can alter sensory characteristics, but sensory characteristics are likely strongly influenced by the microbial composition of the grains/product. Thus, an …

The Development Of A Primer Payload With Microparticles For Uti Pathogen Identification Using Polythymidine- Modified Lamp Primers In Droplet Lamp, Jonas Otoo

KGI Theses and Dissertations

Nucleic acid amplification tests (NAATs) are among the diagnostic tests with the highest sensitivity and specificity. However, they are more complex to develop than other diagnostic tests such as biochemical tests and lateral flow immunoassay tests. Polymerase chain reaction (PCR) is the gold standard for NAATs. PCR requires thermal cycling to achieve clonal amplification of the target pathogen DNA for diagnosis. Thermal cycling poses a challenge in the development of PCR diagnostics for point-of-care (POC) settings. Loop-mediated isothermal amplification (LAMP) offers an isothermal method for NAATs diagnostics. The advancement of the microfluidics field significantly enhances the development of LAMP diagnostics …

Eco-Interoception: What Plants, Fungi And Protista Have Taught My Body, Sara Riley Dotterer

Art Theses and Dissertations

To me, ecology is the relational, full-body awareness that I am made up of and deeply connected to everything around me; and for better or worse, this is reciprocal. I form ecotones, an ecological transitional zone between two ecosystems, with the world around me. I use this ecotonal lens to blur binaries and dissolve boundaries between me and the world “outside my body.” During my Masters of Fine Arts at Southern Methodist University, I have continuously explored and represented the lives of various more-than-human species outside of my body, including plants, fungi and protista through an ecotonal lens. Although these …

Development Of Recombinant Varicella-Zoster Virus Vaccines Expressing Sars-Cov-2 Antigens, Cody Wilson

Honors Theses

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) continues to cause infections and deaths around the globe. Since its emergence, scientists have worked diligently to discover and produce vaccines to battle the virus. While they successfully created and distributed vaccines, the vaccines are not without flaw. These vaccines do not grant long term immunity, require multiple booster shots, and have not prevented the emergence of viral variants. In this study, the SARS-CoV-2 receptor binding domain (RBD), which is a key part of the spike protein (S), and nucleocapsid (N) genetic sequences were inserted into the live varicella …

Mechanistic Examination Of Protist-Mediated Plant Growth Through The Comparative Development Of Medicago Truncatula, Shane Connolly

University Scholar Projects

Protists are known to increase plant growth through two main mechanisms: the microbial loop and the alteration of the root microbiome. The microbial loop is a nutrient recycling method in which protists provide inorganic nitrogen ions to the plant. Alteration of root microbiome leads to the removal of plant pathogens and shifting communities towards plant growth-promoting bacteria (PGPB). This study aimed to elicit which mechanism could produce the largest boost in shoot weight for Medicago truncatula. A series of microcosm experiments were explored in which M. truncatula was grown with variable microbiome structures to allow for mechanism differentiation. The …

The Response Of Microcystis And The Microbiome To Exogenous Hydrogen Peroxide, Bryan A. Puma

Masters Theses, 2020-current

Microcystis spp. produce prolific annual blooms in freshwater systems worldwide. The success of these blooms depends heavily on the Microcystis spp. overcoming environmental factors such as oxidative stress caused by reactive oxygen species (ROS) like hydrogen peroxide. Most Microcystis genomes do not contain many genes for responding to oxidative stress, including those that encode the enzyme catalase. Other cyanobacteria such as Prochlorococcus that also lack hydrogen peroxide degrading enzymes have been shown to benefit from partnerships with heterotrophic bacteria. Microcystis spp. may also receive similar benefits from heterotrophic bacteria in the phycosphere. To test this hypothesis, we examined the …

Causes And Consequences Of Lasr Mutant Selection In Pseudomonas Aeruginosa Populations, Dallas L. Mould

Dartmouth College Ph.D Dissertations

Change is the only constant in life, and these changes, though random in nature, can have consequences. Quorum sensing is heterogeneous in phenotype and prone to negative selection. In P. aeruginosa, the regulator LasR is frequently non-functional in phylogenetically diverse isolates. Through repeated experimental evolution and mathematical modeling, we show that differences in growth enable lasR mutant evolutionary success and this requires a system enabling metabolic choices, known as carbon catabolite repression (or catabolite repression). The differences in catabolite repression between wild type and lasR mutants enable altered metabolite preferences, and the resulting differences in metabolic states enable intraspecies …

Comparative Analysis Of Rhizosphere And Endosphere Microbiome Of Different Blueberry Species (Vaccinium Sp.), Niladri Bhowmik

Master's Theses

Blueberries are an important agricultural commodity in all over the United States. Due to its health benefits, there is a huge demand globally, thus expanding the industry. Breeding programs are essential to maintain such industries. Challenges that play a role in contemporary breeding programs are various biotic and abiotic stress factors. Studies have shown that microorganisms are recruited by plants to alleviate them during stressful conditions. Though blueberries have been cultivated for about 100 years, how the microbiome has been affected due to this is poorly understood. We hypothesized that interspecific crosses and artificial selection have significantly changed the microbiome …

Co-Clinical Imaging Metadata Information (Cimi) For Cancer Research To Promote Open Science, Standardization, And Reproducibility In Preclinical Imaging, Stephen M Moore, James D Quirk, Andrew W Lassiter, Richard Laforest, Gregory D Ayers, Cristian T Badea, Andriy Y Fedorov, Paul E Kinahan, Matthew Holbrook, Peder E Z Larson, Renuka Sriram, Thomas L Chenevert, Dariya Malyarenko, John Kurhanewicz, A Mcgarry Houghton, Brian D Ross, Stephen Pickup, James C Gee, Rong Zhou, Seth T Gammon, Henry Charles Manning, Raheleh Roudi, Heike E Daldrup-Link, Michael T Lewis, Daniel L Rubin, Thomas E Yankeelov, Kooresh I Shoghi

Faculty, Staff and Students Publications

Preclinical imaging is a critical component in translational research with significant complexities in workflow and site differences in deployment. Importantly, the National Cancer Institute's (NCI) precision medicine initiative emphasizes the use of translational co-clinical oncology models to address the biological and molecular bases of cancer prevention and treatment. The use of oncology models, such as patient-derived tumor xenografts (PDX) and genetically engineered mouse models (GEMMs), has ushered in an era of co-clinical trials by which preclinical studies can inform clinical trials and protocols, thus bridging the translational divide in cancer research. Similarly, preclinical imaging fills a translational gap as an …

Elucidating The Impact Of Sos-Response Timing In On Escherichia Coli Survival Following Treatment With Fluoroquinolone Topoisomerase Inhibitors, Stephanie Schofield

Honors Scholar Theses

Antibiotic treatment failure is a public health crisis, with a 2019 report stating that roughly 35,000 deaths occur in the United States yearly due to bacterial infections that are unresponsive to antibiotics (1). One complication in the treatment of bacterial infection is antibiotic persistence which further compromises our battle to effectively treat infection. Bacterial persisters can exist in clonal bacterial cultures and can tolerate antibiotic treatment by undergoing reversible phenotypic changes. They can survive drug concentrations that their genetically identical kin cannot. Some persisters remain in a slow growing state and are difficult to target with current antibiotics. A specific …

A Critical Assessment Of The Role Of Clpxp-Mediated Proteolysis In The Development And Differentiation Of Chlamydia Trachomatis, Nicholas A. Wood

Theses & Dissertations

Chlamydia trachomatis, an obligate intracellular human pathogen, is the etiological agent of the most commonly reported bacterial sexually transmitted infection and the leading cause of preventable infectious blindness worldwide. In adapting to an intracellular niche, Chlamydia has evolved to eliminate superfluous genes from its chromosome. Despite its highly reduced genome, Chlamydia undergoes a complex developmental cycle in which the bacteria differentiate between two functionally and morphologically distinct forms: the infectious, non-replicative elementary body (EB) and the non-infectious, replicative reticulate body (RB). An EB initiates infection by binding to and inducing uptake into a host cell. Within the cell, the EB …

The Future Is Now In Twisted Coil Polymer Actuators (Tcpa), Ryan Ronquillo

Electronic Theses and Dissertations

This thesis aimed to fabricate and test twisted coiled polymer actuators (TCPA) to understand the mechanical and thermal aspects of this artificial muscle fiber. The purpose of this thesis was to find a linear relationship using the LVDT sensor, fabricating TCPA fibers, and interpreting the data. The project tested whether nylon/polymer could be used as a better artificial muscle fiber.

This research accomplished three goals: (1) designing and fabricating a system capable of creating supercoiled muscle fibers consistently, (2) calibrating the Linear Variable Differential Transformer (LVDT) and Core, and (3) analyzing/interpreting the data of the Twisted Coiled Polymer Actuators (TCPA) …

The Role Of Sinorhizobium Meliloti Type Ivb Pili Protein On Legume Nodule Morphology And Infection, Alexis Chun

Honors Thesis

The symbiotic relationship between legumes and rhizobial soil bacteria leads to the conversion of nitrogen gas to biologically available forms of nitrogen. A critical step in this interaction is bacterial attachment to the host root. A variety of factors are involved in attachment, such as the Type IV pili (Tfp). In pathogens, Tfpb mediates tight adherence to host cells, promoting colonization, however in symbiotic interactions, the role of Tfpb–encoded by pilA genes–is not well understood. To assess the role of Tfpb pili during symbiosis, Melilotus alba plants were inoculated with wild type Sinorhizobium meliloti or ΔpilA deletion mutants; roots were …

On The Resurrection Of Microbes: An Eco-Christological Approach To The Resurrection, Denys Janiga Osb

Obsculta

This article attempts to bring ecology and Christology into conversation through a transdisciplinary approach. It looks at the pastoral implications of eco-anxiety, resurrection ecology in the field of biotechnology, Church teaching on the Resurrection, and concludes by initiating an interpretation of the resurrection appearances in the Gospel of Luke through the lens of the microbiome.