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Full-Text Articles in Life Sciences

Utilization Of Ferrioxamine Microarrays For The Rapid Detection Of Pathogenic Bacteria, Nigam Bir Arora Dec 2016

Utilization Of Ferrioxamine Microarrays For The Rapid Detection Of Pathogenic Bacteria, Nigam Bir Arora

Open Access Dissertations

Siderophores are low-molecular weight species utilized by bacteria for the sequestration of iron, an essential nutrient. Siderophores and their cognate receptors are considered to be virulence factors, due to their prominent role in pathogenicity. The work presented here focuses on ferrioxamine (FOx) as an “immutable” ligand for pathogen detection. A number of bacterial strains expressing high-affinity FOx receptors were identified by a proteomic BLAST search, and screened against microarrays patterned with FOx conjugates for detection using label-free optical imaging. Aspects such as inkjet printing and surface chemistry, iron-limiting conditions and bacterial selection protocols, and linker conjugate design were addressed and …


Investigating The Effects Of Ph On Alphaviral E3-E2 Glycoprotein Association, Organization, And Cellular Tropism, Jason Michael Sequra Dec 2016

Investigating The Effects Of Ph On Alphaviral E3-E2 Glycoprotein Association, Organization, And Cellular Tropism, Jason Michael Sequra

Open Access Dissertations

In alphaviruses the role of E3 is required in protecting the fusion peptide region of E1 during intracellular transport. Throughout viral processing, the association of E2 and E3 is required for the successful trafficking and incorporation of E1 into the mature virion. This E3-E2 association has been observed to extend to mature virions in the solved structure for the envelope of Semliki Forest virus (SFV) and supported by the solved structure for the entire Venezuelan equine encephalitis virion (VEEV) with exclusive contacts being made between E3-E2. Immunization with monoclonal antibodies against VEEV E3 provided protection for mice challenged by lethal …


Complex Glycan Utilization Preferences Of Human Gut Bacteria, Yunus Emre Tuncil Dec 2016

Complex Glycan Utilization Preferences Of Human Gut Bacteria, Yunus Emre Tuncil

Open Access Dissertations

Complex glycans, making up dietary fiber, have gained significance in recent years as they are the main energy source for the colonic microbiota which are physiologically important for the host health. Understanding glycan utilization strategies of the members of this community is essential to maximize beneficial health outcomes obtained from them. In order to investigate how the members of our gut microbiota utilize glycans and activate their respective polysaccharide utilization loci (PULs), we performed a series of time-course assays in which two model organisms, Bacteroides thetaiotamicron (Bt) and B. ovatus (Bo), were individually grown in a medium containing carbohydrates utilized …


Genomic And Transcriptomic Analysis Of Biofilm Formation In Persistent And Transient L. Monocytogenes, Clara Assisi Dec 2016

Genomic And Transcriptomic Analysis Of Biofilm Formation In Persistent And Transient L. Monocytogenes, Clara Assisi

Open Access Theses

The Next Generation Sequencing (NGS) has been popularized and aid in the advancement of many fields of science. The other field of science that is being revolutionized is food science and technology, especially food safety. NGS application in food safety, especially the whole genome sequencing analysis (WGS), has been widely used for tracing back the source of outbreaks. The other application of NGS that is also being developed is the analysis of global transcriptomic or RNA-sequencing (RNA-Seq). In this research, we utilize NGS (Ilumina MiSeq Sequencing platform) to perform sequence comparison and identify single nucleotide polymorphisms (SNPs) and observe the …


Repurposing Non-Antimicrobial Drugs To Treat Multi-Drug Resistant Bacterial And Fungal Infections, Shankar Thangamani Dec 2016

Repurposing Non-Antimicrobial Drugs To Treat Multi-Drug Resistant Bacterial And Fungal Infections, Shankar Thangamani

Open Access Dissertations

Bacterial and fungal resistance to conventional antimicrobials is a burgeoning global health epidemic that necessitates urgent action. Even more alarming, the development of new antimicrobials to treat these multidrug-resistant pathogens has not kept pace with the rapid emergence of resistance to current antimicrobials. Antimicrobial drug development through the traditional de novo process is a risky venture given the significant financial and time investment required by researchers and limited success rate of translating these compounds to the clinical setting. This has led researchers to mine existing libraries of clinical molecules in order to repurpose old drugs for new applications (as antimicrobials). …


Antibacterial Activity Of Essential Oil Encapsulated Sodium Iota-Carrageenan Fibers, Carlos D. Carter Dec 2016

Antibacterial Activity Of Essential Oil Encapsulated Sodium Iota-Carrageenan Fibers, Carlos D. Carter

Open Access Theses

Spoilage microorganisms cause food waste and loss of quality. While the foodborne pathogen outbreaks lead to thousands of hospitalizations and deaths. Essential oils (EOs), plant extracts, possess the required antimicrobial activities and thus their usage stands out as a feasible approach for controlling the undesirable bacterial growth in food systems. However, EOs are highly volatile and lose their activity upon exposure to environmental conditions. In this regard, their encapsulation in Generally Recognized As Safe (GRAS) matrices such as food grade polysaccharides especially iota-carrageenan could be one of the viable alternatives. Iota-carrageenan, sulfated polysaccharide from marine algae, is being used in …


Recombinant Listeria Adhesion Protein Expressing Probiotics Protect Against Listeria Monocytogenes Infection In Animal Models, Valerie E. Ryan Dec 2016

Recombinant Listeria Adhesion Protein Expressing Probiotics Protect Against Listeria Monocytogenes Infection In Animal Models, Valerie E. Ryan

Open Access Theses

Listeria monocytogenes (Lm) is a foodborne pathogen, found ubiquitously in nature, and has a high morbidity rate among immunocompromised individuals, the elderly, and especially pregnant women and their fetuses resulting in abortion, stillbirth, and neonatal infection. There are currently no preventative medical interventions against Lm infection. The Listeria adhesion protein (LAP) is present in both pathogenic and non-pathogenic Listeria (i.e., L. innocua) and has shown to interact with host epithelial proteins causing tight junction dysregulation aiding in pathogen attachment and paracellular translocation across the host intestinal epithelium. Our lab has demonstrated that recombinant probiotics, Lactobacillus casei (LbcWT) expressing LAP …


A Compact System For Photon Counting Based On Silicon Photomultiplier, Youngwoo Cho, Youngkee Jung, Euiwon Bae Aug 2016

A Compact System For Photon Counting Based On Silicon Photomultiplier, Youngwoo Cho, Youngkee Jung, Euiwon Bae

The Summer Undergraduate Research Fellowship (SURF) Symposium

A compact and portable detection system is necessary to measure the amount of pollutant from environmental sample by detecting and quantifying the light emitted by bioluminescent reporters. This silicon photomultiplier based project is hoping to acquire even more accurate data at a far lower light level than previously developed smartphone based system. After pre-amplification and comparator, the signal is separated from the internal noise present in the overall circuit. Next, the microcontroller counts the number of pulses generated by the comparator in a set amount of time and transfers the data to the Bluetooth module for the smartphone to receive …


Mitigating Prevalence And Persistence Of L. Monocytogenes Using Novel Sanitation Strategies In Delis, Susan Rose Hammons Aug 2016

Mitigating Prevalence And Persistence Of L. Monocytogenes Using Novel Sanitation Strategies In Delis, Susan Rose Hammons

Open Access Dissertations

Ready-to-eat (RTE) deli meats sliced at retail are predicted to cause 83% of deli meat-associated listeriosis cases annually. While L. monocytogenes is commonly found in delis (55-90%), environmental prevalence varies by store (0-40%). Study 1 evaluated efficacy of 10 standardized SSOPs by testing 28 food and non-food contact surfaces for L. monocytogenes over 6 months in 30 retail delis. Intervention strategies employed in this study significantly decreased L. monocytogenesprevalence on FCS and NFCS in stores with moderate prevalence (0.5%, 0.8% reduction). However, we found that L. monocytogenes could persist despite implementation of SSOP control strategies. Study 2 assessed an …


Affinity Cryo-Electron Microscopy: Methods Development And Applications, Guimei Yu May 2016

Affinity Cryo-Electron Microscopy: Methods Development And Applications, Guimei Yu

Open Access Dissertations

Single particle cryo-electron microscopy (cryo-EM) is an emerging powerful tool for structural studies of macromolecular assemblies. Although less concentrated and smaller amounts of samples are required for single particle cryo-EM compared to X-ray crystallography, it remains challenging to study specimens that are low-abundance, low-yield, or short-lived. The recent development of affinity grid techniques holds great promise to tackle these challenging samples by combining the sample purification and freezing on TEM grids steps in cryo-EM grid preparation into a single step, revolutionize the grid preparation of cryo-EM, and extend single particle cryo-EM to a routine structural biology tool to characterize structures …


Magnesium Regulates Transcription Of The Mgta (Magnesium Transporter) Gene In Salmonella Enterica Serovar Typhimurium Via Prolyl-Bond Formation During Translation Of The Mgtl Leader Orf, Aaron R. Gall Apr 2016

Magnesium Regulates Transcription Of The Mgta (Magnesium Transporter) Gene In Salmonella Enterica Serovar Typhimurium Via Prolyl-Bond Formation During Translation Of The Mgtl Leader Orf, Aaron R. Gall

Open Access Dissertations

In Enterobacteriaceae, the mgtA gene encodes a P-type ATPase that mediates Mg2+ uptake and is up-regulated by the PhoQP two-component system during invasion of host epithelial cells and macrophages. The regulation of mgtA has recently gained special interest given that it exists at several stages, including transcription, post-transcription and post-translation, in response to Mg2+availability. The mgtA mRNA has a 264-nucleotide 5’ leader that contains a 17 codon, proline-rich ORF, termed mgtL, whose translation has been proposed to affect the folding of the 5’ leader mRNA, which in turn regulates whether transcription is terminated before the mgtA structural gene at high …


Community-Scale Water Treatment Systems In The Dominican Republic, Water Supply In The Dr Mar 2016

Community-Scale Water Treatment Systems In The Dominican Republic, Water Supply In The Dr

Engagement & Service-Learning Summit

No abstract provided.


Investigating Physiological Collaborations Between A Lower Termite And Its Symbionts, Brittany F. Peterson Mar 2016

Investigating Physiological Collaborations Between A Lower Termite And Its Symbionts, Brittany F. Peterson

Open Access Dissertations

This project was completed in an effort to better understand the contributions of symbiotic microbes to the biology of Reticulitermes flavipes, the eastern subterranean termite. Lower-termites, like R. flavipes, house symbionts from all three domains of life within their hindgut paunch. This intimate association is reflected in nearly every aspect of termite biology. Here, I investigate these physiological collaborations as they relate to digestion and immunity. My efforts focused on 1) quantifying the role of bacteria in wood digestion within the termite gut, 2) evaluating the role of symbionts in protection against pathogens, and 3) identifying gene products that bacterial …


Factors Affecting Transduction Efficiency Of Pseudotyped Viral Vectors Incorporating Alphaviral Glycoproteins, Aditi Kesari Mar 2016

Factors Affecting Transduction Efficiency Of Pseudotyped Viral Vectors Incorporating Alphaviral Glycoproteins, Aditi Kesari

Open Access Dissertations

The genome of an organism has the complete set of biochemical instructions required for sustenance of life. Mutations or abnormalities in this genome lead to genetic disorders. Currently available therapeutic options mostly focus on treating the symptoms, but not curing them. Gene therapy promises to be a curative form of medicine. In gene therapy cells carrying a defective gene are targeted and replaced with a healthy copy of that gene. The vehicles used for delivering this gene are known as vectors. Retroviruses are popularly used gene therapy/transfer vectors. However, retroviruses are limited in the range of cells they can enter …