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Loyola University Chicago

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Full-Text Articles in Life Sciences

The Characterization Of Rna Content And Biogenesis Pathways Of Extracellular Vesicles That Have Been Implicated In The Pathogenesis Of Hiv-1 Associated Neurocognitive Disorders, Virginia Elizabeth Zwikelmaier Jan 2018

The Characterization Of Rna Content And Biogenesis Pathways Of Extracellular Vesicles That Have Been Implicated In The Pathogenesis Of Hiv-1 Associated Neurocognitive Disorders, Virginia Elizabeth Zwikelmaier

Master's Theses

Patients infected with HIV-1 adhering to Anti-Retroviral Therapy (ART) still suffer from a variety of neurocognitive, behavioral, and motor dysfunctions, collectively referred to has HIV-1 Associated Neurocognitive Disorders (HAND). Current research suggests the manifestations of HAND might in part be due to the dissemination of toxic HIV-1 components throughout the brain via extracellular vesicles (EVs). Our goal is to characterize these pathogenic EVs to begin to gain a better understanding of this EV-mediated pathology.

We took the first steps in developing a technique to assess the microRNA content of individual EVs but it needs to be heavily optimized to eliminate ...


Cryptic Diversification Of Two Widespread Species In Madagascar, Lynika Sharlice Strozier Jan 2018

Cryptic Diversification Of Two Widespread Species In Madagascar, Lynika Sharlice Strozier

Master's Theses

Using phylogenetic and phylogeographic tools to uncover hidden diversity within the genus Newtonia in Madagascar

Madagascar is known for its rich biodiversity and high level of endemic species that are found nowhere else. Cryptic diversification, defined as genetically and evolutionarily distinct species that are hard to detect because they are morphologically indistinguishable from their closest relatives, has been hypothesized to occur in many groups on Madagascar. Currently it is unclear to what extent this phenomenon occurs in birds because only a few studies have been conducted. My study examined the phylogenetic and phylogeographic patterns within a songbird genus, Newtonia, that ...


Chironomidae (Diptera) Community Structure In Lakes Of Contrasting Morphometry, Landscape Position, And Water Chemistry, Conrad Stanley Zack Jan 2018

Chironomidae (Diptera) Community Structure In Lakes Of Contrasting Morphometry, Landscape Position, And Water Chemistry, Conrad Stanley Zack

Master's Theses

Chironomidae (Diptera) surface-floating pupal exuviae were collected monthly during the ice-free season in 2010-2011 from six lakes in the North Temperate Lakes Long-Term Ecological Research site in northern Wisconsin. The goal of this study was to determine whether chironomid community structure reflected differences in lake morphometry (i.e., depth, area, shoreline development, etc.), water chemistry, and/or landscape position (i.e., elevation). Forty-six genera were identified from four subfamilies: Chironominae (57%), Orthocladiinae (28%), Tanypodinae (11%), and Diamesinae (4%). Tanytarsus, Ablabesmyia, and Psectrocladius were found in all six study lakes; whereas certain genera, such as Omisus, Protanypus, and Epoicocladius were each ...


Surveying Host Innate Immune Responses To Interferon Antagonist-Deficient Murine Coronaviruses, Aaron Brian Volk Jan 2018

Surveying Host Innate Immune Responses To Interferon Antagonist-Deficient Murine Coronaviruses, Aaron Brian Volk

Master's Theses

Two coronaviruses (CoVs)—severe acute respiratory syndrome (SARS) virus and Middle East respiratory syndrome (MERS) virus—have emerged in the 21st century from animal reservoirs into the human population, each causing an epidemic associated with significant disease and mortality. CoV epidemics are currently only controllable by rigorous public health measures; no targeted therapeutics or vaccines exist to treat or prevent any human CoV infection. One method of generating attenuated CoV strains to be studied as vaccine candidates involves specifically disrupting CoV-encoded interferon (IFN) antagonists, thereby rendering the virus vulnerable to host innate antiviral immunity. Deubiquitinating (DUB) activity encoded within CoV ...


Characterizing The Requirement Of The Cmi/Trr Compass-Like Complex During Drosophila Development, Timothy Nickels Jan 2018

Characterizing The Requirement Of The Cmi/Trr Compass-Like Complex During Drosophila Development, Timothy Nickels

Master's Theses

The MLR family of COMPASS-like complexes are histone methyltransferase complexes that are associated with the activation of gene enhancers. In D. melanogaster, Cara mitad (Cmi, also known as Lpt) and Trithorax related (Trr) are central subunits of a complex orthologous to mammalian Lysine methyltransferase 2 C and D (KMT2C and KMT2D, also known as MLL3 and MLL2/4) that catalyze H3K4 monomethylation. Previous studies have demonstrated that mutations in these genes are associated with cancer and developmental disorders, but the mechanisms by which these alterations contribute to disease states are unknown. The Cmi-containing COMPASS-like complex and orthologous vertebrate complexes have ...


Investigating Autophagy, Extracellular Vesicles, And Glycobiology, Benjamin Cook Jan 2018

Investigating Autophagy, Extracellular Vesicles, And Glycobiology, Benjamin Cook

Master's Theses

Autophagy is a cellular process of degradation which degrades cellular materials in acidic organelles called lysosomes. Impairment of lysosomal degradation can lead to lysosomal storage disorders such as Parkinson's Disease. In Parkinson's Disease neurotoxic α-synuclein can spread from cell-to-cell via extracellular vesicles. We investigated the changes in extra vesicular glycans upon perturbation of autophagy using a class of glycan binding molecules termed lectins.

We found that upon induction of autophagy causes EV glycans to increase while others remained consistent. Additionally, we found that specific glycans are increased more than others. Conversely, when lysosomal degradation was impaired, we ...


Induction Of Zika Virus-Specific Cd8+ T Cells By Means Of Dna Vaccine, Frank Gambino Jr. Jan 2018

Induction Of Zika Virus-Specific Cd8+ T Cells By Means Of Dna Vaccine, Frank Gambino Jr.

Master's Theses

Zika virus (ZIKV) is a member of the virus family flaviviridae and is transmitted via Aedes aegypti mosquitos. Monoclonal antibodies against dengue virus have been found to cross-react with ZIKV but show no ability to neutralize it. Further studies have shown that Stat2-/- mice given plasma from dengue positive donors exhibit a heightened disease phenotype when challenged with ZIKV. Antibody dependent enhancement is theorized to cause such effect. The goal of this study was to design a plasmid which, when encoded, creates an antigen that will be used to stimulate exclusively CD8+ T cells. The gene sequence of NS3 was ...


Cell Intrinsic Characteristics Of Cord Blood Naive Cd4 T Cells, Taylor Keller Jan 2018

Cell Intrinsic Characteristics Of Cord Blood Naive Cd4 T Cells, Taylor Keller

Master's Theses

The neonatal immune system is functionally distinct from the adult immune system. Neonatal immune responses are less reactive than their adult counterparts, and as such, have an increased susceptibility to infection, resulting in increased duration and severity of disease. There is evidence that T-cells are partially responsible for the observed immunological differences between neonates and adults. Murine studies on neonatal immunity suggest that Th2 like responses predominate the neonatal immune system, an observation not found in the adult immune system. However, studies on human cord blood revealed that human neonates do not exhibit elevated Th2 like cytokines (with the exception ...


Immunobiology Of Adenovirus-Vector Vaccines For Mrsa, Emily Orvis Jan 2018

Immunobiology Of Adenovirus-Vector Vaccines For Mrsa, Emily Orvis

Master's Theses

Staphylococcus aureus is a gram-positive, extracellular bacterium that has emerged as an

important human pathogen. This bacterium is a leading cause of skin and soft tissue infections

(SSTIs) in humans, often leading to invasive and life-threatening infections. Treatment of S.

aureus infections is becoming more complicated due to the rise of methicillin-resistant S. aureus

(MRSA) strains, which are becoming increasingly resistant to a number of antibiotics. In the

United States, invasive MRSA infections result in more deaths annually than any other infectious

agent.

Despite a dire need, there is currently no vaccine against S. aureus infections. The failure

of past ...


Nitric Oxide Inhibits Biofilm Formation By Vibrio Fischeri Via The Nitric Oxide Sensor Hnox, Cecilia Thompson Jan 2018

Nitric Oxide Inhibits Biofilm Formation By Vibrio Fischeri Via The Nitric Oxide Sensor Hnox, Cecilia Thompson

Dissertations

Nitric oxide (NO) is an important signal secreted by the squid, Euprymna scolopes, and is thought to limit symbiotic biofilm formation, the initial step in colonization by the bacterium, Vibrio fischeri. Previous work demonstrated that a mutant defective for NO-sensor HnoX (heme nitric oxide/oxygen binding) had a competitive advantage over wild-type V. fischeri, but the mechanism by which this occurred remains unknown. HnoX is encoded upstream of hahK, a recently identified positive regulator of biofilm formation. I thus hypothesized that HnoX inhibits colonization by controlling HahK-induced biofilm formation during the initiation of colonization.

I assessed the impact of an ...


Characterizing Immune Response To Hiv-1 Infection In Bicd2-Knockout Cells, Omar Abdel-Rahim Jan 2018

Characterizing Immune Response To Hiv-1 Infection In Bicd2-Knockout Cells, Omar Abdel-Rahim

Master's Theses

An important part of the HIV-1 infection cycle is the attachment of the intracellular viral core to the host microtubule network, facilitated by attachment of the viral capsid to cargo adaptor proteins. One such cargo adaptor is Bicaudal D Homolog Protein 2 (BICD2). BICD2 can attach to both the HIV-1 capsid and the dynein/dynactin complex and facilitate the trafficking of the viral core towards the host nucleus. Removal of BICD2 can disrupt this viral translocation, resulting in an elevated immune response that impairs productive HIV-1 infection. In my research, we investigated what viral particles are detected in the absence ...


Molecular Determinants Of Trim5Α Restriction And Recruitment Of Autophagic Effectors, Sabrina Imam Jan 2018

Molecular Determinants Of Trim5Α Restriction And Recruitment Of Autophagic Effectors, Sabrina Imam

Dissertations

TRIM5α is an anti-viral restriction factor that inhibits the lifecycle of retroviruses. TRIM5α binds to and forms a hexameric lattice around the retroviral capsid, thereby initiating its antiviral activities, which include: (1) inhibition of viral infection; (2) inhibition of viral reverse transcription; (3) disassembly of the capsid; and (4), activation of innate signaling pathways. The formation of this assembly also activates the E3 ubiquitin ligase function of TRIM5α. Ubiquitin modification is associated with directing substrates to particular cellular pathways. We and others have shown that TRIM5α cytoplasmic bodies colocalize with proteins involved in the autophagy pathway, and we hypothesized that ...


Uncovering The Mechanisms Underlying The Immunogenicity Of Adenovirus Vaccine Vectors, Natalie Nidetz Jan 2018

Uncovering The Mechanisms Underlying The Immunogenicity Of Adenovirus Vaccine Vectors, Natalie Nidetz

Dissertations

Vaccination is historically the most effective tool for preventing infectious disease but current vaccine strategies fail to generate robust immunity to major infectious diseases such as HIV and malaria. Therefore, newer vaccine approaches are needed. Vaccines generated from viral, adenovirus based, vectors (AdVs) have proven highly immunogenic in multiple disease models. However, the clinical use of many AdVs is limited by the presence of pre-existing antibodies in human populations, which prevent expression of antigenic genes during immunization with AdVs based on common adenovirus (Ad) serotypes, such as HAdV-5C. Immunization with rare serotype based AdVs, such as HAdV-28D, are not affected ...


A Discrete Loop In Serca N-Domain Plays A Role In Serca Headpiece Dynamics And Function, Olga N. Raguimova Jan 2018

A Discrete Loop In Serca N-Domain Plays A Role In Serca Headpiece Dynamics And Function, Olga N. Raguimova

Dissertations

The sarco/endoplasmic reticulum calcium ATPase (SERCA) is the major regulator of Ca2+ levels in the cell. Deficient calcium handling in the heart has been linked to heart failure, a leading cause of death in developed countries. As of today, targeting SERCA to enhance cardiac function has not been successful due to lack of details about SERCA structural dynamics during Ca2+ transport.

In my research, I utilized MD simulations and variety of physical assays to determine the role of Nβ5-β6 loop in regulation of SERCA structural dynamics during Ca2+ transport. Previous MD simulations by our lab predicted that the Nβ5-β6 ...


Comparison Between The Structure-Function Relationship In The Wild Type Gαi1 Protein And Its Oncogenic Mutant, Jesse Lee Goossens Jan 2018

Comparison Between The Structure-Function Relationship In The Wild Type Gαi1 Protein And Its Oncogenic Mutant, Jesse Lee Goossens

Dissertations

Many signal transduction pathways are regulated by guanine nucleotide-binding (G?) proteins, which function as molecular switches fluctuating between active and inactive conformations. Proper function depends on three flexible switch regions that are involved in the relatively slow hydrolysis of GTP. Deep sequencing studies have found mutations in the GNAS and GNAI1 genes involved in tumorigenesis, among which include a mutation corresponding to a highly conserved arginine residue in the switch II region. A mutation in GNAI1 encoding an R208Q change in G?i1 has been linked to intestinal cancers. We investigated the molecular basis of oncogenesis of this mutant by ...


Role Of Micrornas In Impaired Gut Permeability Following Ethanol And Burn Injury, Niya Latrice Morris Jan 2018

Role Of Micrornas In Impaired Gut Permeability Following Ethanol And Burn Injury, Niya Latrice Morris

Dissertations

Every year there are nearly 500,000 reported burn injuries in the United States; half of which occur under the influence of alcohol. Clinical studies have shown that burn patients who are intoxicated at the time of injury have a worse prognosis; including increased risk of multiple organ dysfunction syndrome (MODS) and sepsis. The etiology behind these pathological consequences of ethanol and burn injury remains to be elucidated. The Gut-lymph hypothesis of MODS theorizes that trauma (e.g. ethanol and burn injury) results in a redistribution of blood flow to protect more vital organs which leads to ischemia/hypoxia (diminished ...


Population Genetics And Distribution Of The Oriental Weatherfish, Misgurnus Anguillicaudatus, In Chicago Area Waterways, John Belcik Jan 2017

Population Genetics And Distribution Of The Oriental Weatherfish, Misgurnus Anguillicaudatus, In Chicago Area Waterways, John Belcik

Master's Theses

Oriental Weatherfish (Misgurnus anguillicaudatus), native to Southeast Asia, are freshwater fish belonging to the family Cobitidae (loaches). They are benthic fish with the ability to breathe atmospheric air, and exhibit an unusual behavior of swimming vertically in the water column in response to changes in barometric pressure. Oriental Weatherfish appear to be successful invaders to North American waterways. Within the last century they have been sighted in freshwater systems throughout the United States, yet the distribution and source of this invasion are largely unknown. This study investigates the distribution patterns, surveying methods, and population genetics of the Oriental Weatherfish within ...


Aquatic Insect Community Structure And Secondary Production In Coastal Wetland Ponds Of The Copper River Delta, Alaska: Influence Of Water Temperature And Macrophyte Community Structure, Chantel Caldwell Jan 2017

Aquatic Insect Community Structure And Secondary Production In Coastal Wetland Ponds Of The Copper River Delta, Alaska: Influence Of Water Temperature And Macrophyte Community Structure, Chantel Caldwell

Master's Theses

The Copper River Delta (CRD), southcentral Alaska, is one of the world’s largest continuous coastal wetlands and is largely composed of sloughs, lakes, and ponds. Due to coastal topography the east side of the Copper River (East Delta) is disproportionately impacted by a cold continental air mass. Wetland communities of the CRD were also impacted by a 9.2 magnitude earthquake in 1964 that shifted the more coastal portion of the CRD from tidally influenced ponds to freshwater ponds.

The West-East temperature gradient across the CRD coupled with landscape type (uplifted marsh (UM) and outwash plain (OP)) creates four ...


The Role Of Phage Trnas In The Evolution Of Codon Usage Biases In Giant Pseudomonas Phage Phikz And El, Stephanie Steidel Jan 2017

The Role Of Phage Trnas In The Evolution Of Codon Usage Biases In Giant Pseudomonas Phage Phikz And El, Stephanie Steidel

Master's Theses

As the most abundant and diverse biological agents in the biosphere phage have significant roles in microbial ecology, acting both as lethal bacterial parasites and vehicles of horizontal gene transfer. Phage/host coevolution drives optimization of phage codon usage for use of host translational machinery, thus lowered correspondence between phage and host codon usage reduces viral fitness. Some phage may partially bypass host translational selection on their codon usage by encoding their own tRNAs, although the effects of these tRNAs on phage codon usage and translation has not been well examined. This work explores the influence of phage encoded tRNAs ...


Functional Studies Of Novel Mosquito Stage-Specific Genes In The Malaria Parasite, Plasmodium Berghei., Kaitlyn Kiernan Jan 2017

Functional Studies Of Novel Mosquito Stage-Specific Genes In The Malaria Parasite, Plasmodium Berghei., Kaitlyn Kiernan

Master's Theses

The development and survival of the malaria parasite Plasmodium within its mosquito vector is not very well understood. When the parasite is taken up by an Anopheles mosquito, it is exposed to digestive enzymes, reactive oxygen species, increasing pH, decreasing temperature, and a diverse microbial flora. Our lab is studying the adaptive mechanisms underlying parasite survival in this hostile environment, one of which is movement out of the midgut. In order to escape the midgut, the parasite develops into an elongated, motile form called the ookinete. I am investigating two genes, thioredoxin-like protein 1 (trxl-1) and subpellicular microtubule protein 1 ...


Dexamethasone Treatment Effects On H3k27me3 Chromatin Organization Is Related To Nk Cell Immune Dysregulation, Michael Sarafeno Misale Jan 2017

Dexamethasone Treatment Effects On H3k27me3 Chromatin Organization Is Related To Nk Cell Immune Dysregulation, Michael Sarafeno Misale

Master's Theses

It is well-established that psychological stress reduces natural killer (NK) cell immune function. This reduction is mediated by stress-induced release of glucocorticoids (GC), which can suppress immune function. Associated with suppression of a particular immune function are GC induced histone-epigenetic marks. Histone-epigenetic marks are responsible for the organization and compartmentalization of genomes into transcriptionally active euchromatin domains that are localized to the interior of the nucleus. Transcriptionally silent heterochromatic domains are enriched with methylated epigenetic marks and are localized to the nuclear periphery. The purpose of this investigation was to assess the influence of GC on H3K27me3 chromatin organization by ...


Multifunctional Regulatory T Cells From Human Umbilical Cord Blood And The Role Of Tumor Necrosis Factor In Immune Homeostasis, Alexander Nelson Jan 2017

Multifunctional Regulatory T Cells From Human Umbilical Cord Blood And The Role Of Tumor Necrosis Factor In Immune Homeostasis, Alexander Nelson

Master's Theses

Regulatory T cells (Tregs) are required to suppress inflammation and prevent autoimmunity. During fetal development Tregs are crucial to maintain tolerance between mother and child. After birth, neonates require tolerance to avoid harmful immune responses to foreign antigens in food and allow colonization with commensal microbes. We demonstrate a propensity for T cells in human umbilical cord blood to differentiate into Tregs in response to antigen receptor stimulation ex vivo. Cord blood-derived Tregs potently suppress T cell proliferation, but also produce pro-inflammatory cytokines known to activate innate immune responses. These results suggest that antigen exposure during early life results in ...


Chronic Effects Of Lead Exposure On Atherinops Affinis (Topsmelt): Influence Of Salinity And Organism Age, Erik Joseph Reynolds Jan 2017

Chronic Effects Of Lead Exposure On Atherinops Affinis (Topsmelt): Influence Of Salinity And Organism Age, Erik Joseph Reynolds

Master's Theses

Pb (lead) appears in the environment as a consequence of both natural and anthropogenic processes. Mining, smelting, coal burning, lead acid batteries, and cement manufacturing substantially release Pb into aquatic environments. The goal of this study was to determine the influence of salinity and organism age on chronic toxicity of Pb to Atherinops affinis (topsmelt) in support of development of a species sensitivity distribution (SSD). Species sensitivity distributions assist in ecological risk assessments and establishing quality criteria for contaminants. Three chronic exposure studies were conducted for 28 days in a water flow-through testing system. Survival, standard length, dry weight, and ...


The Effects Of Treating Multispecies Biofilms With Bacteriophage, Alexandria Francis Cooper Jan 2017

The Effects Of Treating Multispecies Biofilms With Bacteriophage, Alexandria Francis Cooper

Master's Theses

Biofilms can be found in any environment within proximity to water and are problematic in an assortment of industries. Numerous efforts have been employed to dislodge biofilms including bacteriophages (viruses that infect bacteria). Phage remediation is a promising solution for combatting biofilms that form on catheters in long term use patients. These biofilms often result in catheter-associated urinary tract infections (CAUTIs) and are the most common type of healthcare related infection reported. Additionally, they result in longer hospital stays and increased morbidity. To date, most of the research on the topic focuses on single species biofilms, despite their rarity in ...


Potential Efficacy Of Targeting Mll1 In Breast Cancer, Austin Gable Holmes Jan 2017

Potential Efficacy Of Targeting Mll1 In Breast Cancer, Austin Gable Holmes

Master's Theses

In 2017, it is estimated that breast cancer will be the most prevalent newly diagnosed cancer in females, at 30% in the U.S. alone1. From the early 1990s to 2014 the death rate in females from breast cancer has dropped by 10% but still stands as the second highest cancer related death in females in the U.S.2. One of the biggest hurdles in breast cancer research is disease heterogeneity. New mechanisms of disease development and progression are encountered frequently. One mechanism studied in the past decades is epigenetics. It has been theorized that the cancer epigenome can ...


The Novel Characterization Of Extracellular Vesicles Containing Proteins Which Have Been Implicated In The Pathogenesis Of Hiv Associated Neurocognitive Disorders, Grace Ispas Jan 2017

The Novel Characterization Of Extracellular Vesicles Containing Proteins Which Have Been Implicated In The Pathogenesis Of Hiv Associated Neurocognitive Disorders, Grace Ispas

Master's Theses

Although Anti-Retroviral Therapy (ART) is practiced, HIV-1 positive individuals still experience HIV-Associated Neurocognitive Disorders (HAND), collectively described as the presentation of neurocognitive, behavioral and motor dysfunctions that decrease the quality of life, while increasing the mortality in ART suppressed HIV-1 positive patients.

Current literature suggests that extracellular vesicles are involved in the pathogenesis of HAND as they are believed to be transferring HIV-1 proteins to nearby neuronal cells. Although most studies assume homogeneity among populations, characterizing cellular proteins or RNA levels in bulk, we hypothesize that distinct populations of extracellular vesicles are released and that environmental conditions, including viral infections ...


Optimizing Clean Catch Urine Collection And Its Applications In Urinary Microbiome Studies, Danielle Johansen Jan 2017

Optimizing Clean Catch Urine Collection And Its Applications In Urinary Microbiome Studies, Danielle Johansen

Master's Theses

Clean catch was developed before the advancement of more sensitive assays for culturing urinary bacteria. I reassessed clean catch, endeavoring to optimize this method. Periurethral swabs and voided urines were routinely collected, while analyzing different aspects of the method. I determined that midstream urine contained the least amount of vulvo-vaginal contamination and that the time of collection did not impact the results. I also determined that the use of antiseptic wipes prior to void increased the level of vulvo-vaginal contamination. A small cohort of females collected daily urines over a 17-day period and kept a strict alcohol diary. Females who ...


Phenotyping Temperature-Sensitive Coronaviruses, Amani Eddins Jan 2017

Phenotyping Temperature-Sensitive Coronaviruses, Amani Eddins

Master's Theses

Coronaviruses (CoVs) can cause a range of symptoms; from a mild common cold to life threatening acute respiratory distress syndrome (ARDS) upon infection. These emerging viruses have the ability to be highly pathogenic and detrimental to the human population. Two prime examples of CoV emergence, SARS-CoV (Severe Acute Respiratory Syndrome) and MERS-CoV, (Middle Eastern Respiratory Syndrome), which exhibits the pandemic potential of emerging CoVs that gain human tropism. Given the increasing potential of an emerging CoV outbreak there is a state of urgency to develop vaccines that will help protect the human population against current and future circulating strains. The ...


Utilizing Genetic Techniques To Identify Amino Acids Within The Putative Glycosyltransferase Sypq That Are Essential For Its Role In Biofilm Formation By Vibrio Fischeri, Mary Kathryn Flaherty Jan 2017

Utilizing Genetic Techniques To Identify Amino Acids Within The Putative Glycosyltransferase Sypq That Are Essential For Its Role In Biofilm Formation By Vibrio Fischeri, Mary Kathryn Flaherty

Master's Theses

The polysaccharide component of the V. fischeri biofilm is produced by proteins encoded by the symbiosis polysaccharide (syp) locus. The syp locus encodes 18 genes, six of which are putative glycosyltransferases (GTs). One of these GTs, sypQ, encodes a putative family 2 glycosyltransferase (GT-2). The mechanism by which SypQ facilitates biofilm formation is not yet understood. To uncover which specific residues are essential for the function of SypQ, I utilized Bioinformatics, site-directed mutagenesis, and random mutagenesis. The Bioinformatics identified putative GT-2 motifs in the SypQ primary sequence. The mutagenesis (both site-directed and random), identified five residues (D95, D151, S153, D236 ...


Characterization Of Inhibitory Molecules Produced By Lactobacillus Crispatus, Giuseppe Anthony Pistone Jan 2017

Characterization Of Inhibitory Molecules Produced By Lactobacillus Crispatus, Giuseppe Anthony Pistone

Master's Theses

Lactobacillus species are widely accepted as beneficial bacteria of the human microbiota1-8. Lactobacilli spp. are well documented to inhibit pathogens by production and secretion of hydrogen peroxide (H2O2), organic acids, and/or proteinaceous bacteriocins into their environment. Most research attributes bactericidal activity of cell free supernatant (CFS) to H2O2 and/or lactic acid. Here, I demonstrate that CFS from a clinical isolate of Lactobacillus crispatus contains a molecule(s) that inhibits uropathogenic Escherichia coli (UPEC) colony formation independently of H2O2 and organic acids. Physiologic concentrations of H2O2 and organic acids produced by L. crispatus do not inhibit UPEC colony formation ...