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Elucidating The Impact Of Sos-Response Timing In On Escherichia Coli Survival Following Treatment With Fluoroquinolone Topoisomerase Inhibitors, Stephanie Schofield May 2023

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 …


Oncolytic Virus Immunotherapy: Development And Potential For Cancer Treatment, Olivia Guinness May 2023

Oncolytic Virus Immunotherapy: Development And Potential For Cancer Treatment, Olivia Guinness

Honors Scholar Theses

The American Cancer Society estimates that in 2023, 1,958,310 new cancer cases and 609,820 cancer deaths will occur in the United States [16]. A promising therapeutic option that has been supported by recent clinical trials is the use of oncolytic viruses to treat malignant tumors. The mechanism of action of existing treatments, such as chemotherapy, radiotherapy, and surgery, differs from that of oncolytic virus therapy because oncolytic viruses are able to affect cancer cells with specificity, minimizing side effects. When infecting a normal, non-cancerous cell, oncolytic viruses do not replicate, leaving healthy cells unaffected. In tumor cells, oncolytic viruses will …


Eskape Pathogens: The Clinical Prevalence And Molecular Mechanisms Of Antibiotic Resistance, Anusha Attre May 2022

Eskape Pathogens: The Clinical Prevalence And Molecular Mechanisms Of Antibiotic Resistance, Anusha Attre

Honors Scholar Theses

The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are the leading cause of all nosocomial, or healthcare-associated (HAI), infections (Navidinia, 2016). The purpose of this research study is to determine the burden of ESKAPE infections on healthcare and study the antibiotic resistance in these high-risk pathogens to provide direction for researchers to develop new antimicrobial innovations to reduce ESKAPE infectivity and improve patient outcomes. To study the burden of ESKAPE infections, this review analyzes the current statistics explaining the clinical prevalence of each pathogen in causing HAIs. Additionally, each pathogen is …


Alterations Of The Gut Mycobiome In Patients With Ms - A Bioinformatic Approach, Saumya Shah May 2022

Alterations Of The Gut Mycobiome In Patients With Ms - A Bioinformatic Approach, Saumya Shah

Honors Scholar Theses

The mycobiome is the fungal component of the gut microbiome and is implicated in several autoimmune diseases. However, its role in multiple sclerosis (MS) has not been studied. We performed descriptive and formal statistical tests using the R language to characterize the gut mycobiome in people with MS (pwMS) and healthy controls. We found that the microbiome composition of multiple sclerosis patients is different from healthy people. The mycobiome had significantly higher alpha diversity and inter-subject variation in pwMS than controls. Additionally, Saccharomyces and Aspergillus were over-represented in pwMS. Different mycobiome profiles, defined as mycotypes, were associated with different bacterial …


Study Of A Putative Niche Adapting Operon In Microbes Inhabiting The Gut Of Blood Digesting Animals, Marlene Abouaassi Aug 2020

Study Of A Putative Niche Adapting Operon In Microbes Inhabiting The Gut Of Blood Digesting Animals, Marlene Abouaassi

Honors Scholar Theses

The sialic acid utilization (SAU) operon is a horizontally acquired gene set that allows bacteria to utilize sialic acid as an alternate source of carbon and nitrogen in the guts of blood eating animals. Sialic acid often occurs as a terminal sugar in complex glycoproteins. It functions in cell signaling and adhesion. Sialic acid is an important component of the cellular envelope of animals. Some microorganisms have evolved to decorate their own surface with sialic acid to evade the host’s immune response (molecular mimicry). The SAU operon encodes enzymes that hydrolyze sialic acid from glycoproteins, transport sialic acid into the …


Contributions Of Gyra And Parc Mutations And Qnrs2 Acquisition To Ciprofloxacin Resistance In Aeromonas Veronii Hm21, Daniel J. Silverstein Jun 2020

Contributions Of Gyra And Parc Mutations And Qnrs2 Acquisition To Ciprofloxacin Resistance In Aeromonas Veronii Hm21, Daniel J. Silverstein

Honors Scholar Theses

In recent years, ciprofloxacin resistant (CpR) Aeromonas veronii and A. hydrophila strains have been isolated from the wounds of patients receiving leech therapy. Genome comparisons of these CpR isolates revealed the presence of chromosomal mutations in gyrA and parC as well as the gain of qnrS2 on either a large, 34 kb, conjugatable, low-copy plasmid, pAv42, or on a small, 6.8 kb, high-copy plasmid, pAh1471. The minimum inhibitory concentration, MIC, for Cp of these clinical isolates ranged from 1 to ≥32 µg/mL and some harbored a qnrS2 containing plasmid. We wanted to assess the contributions of these factors in an …


3,4-Dihydroxyphenylacetate 2,3-Dioxygenase Modulates The Ability Of Enterobacter Hormaechei To Induce Cryptococcus Neoformans Melanization, Amy Nelson Jun 2020

3,4-Dihydroxyphenylacetate 2,3-Dioxygenase Modulates The Ability Of Enterobacter Hormaechei To Induce Cryptococcus Neoformans Melanization, Amy Nelson

Honors Scholar Theses

In this study, we performed transposon mutagenesis to create a library of Enterobacter hormaechei mutants and developed a melanization assay to identify mutants that could not induce the typical melanization phenotype in Cryptococcus neoformans. Relevant phenotype labels included: “hypomelanizer”, a total lack of melanization; “hypermelanizer”, an increased melanization; or “abnormal”, an increased melanization with complete color change of the assay plate to a reddish-brown. Genomic sequencing of 47 mutants and bioinformatic analysis allowed us to pinpoint the transposon insertion site in each E. hormaechei mutant to identify the genes that were affected. A single mutant that induced the abnormal …


Tyrr Regulates The Ability Of Enterobacter Hormaechei To Induce Melanin Production In Cryptoccus Neoformans, Ally Watson May 2020

Tyrr Regulates The Ability Of Enterobacter Hormaechei To Induce Melanin Production In Cryptoccus Neoformans, Ally Watson

Honors Scholar Theses

The yeast Cryptococcus neoformans is present in the microbiota of many plants and animals and produces melanin, a compound that protects cells against UV light and promotes virulence. Melanin production can be induced by exogenous tyrosine, homogentisic acid, catecholamines, or their precursors such as L-DOPA, all of which may be produced by bacteria. The goal of this study was to investigate the interaction between Enterobacter hormaechei (a mosquito gut isolate) and C. neoformans with respect to the production of melanin by C. neoformans in the presence of E. hormaechei, potentially due to the production of L-DOPA or other metabolites …


Rapid Antibiotic Susceptibility Testing Platform For Direct Clinical Samples, Terrance Zhang May 2020

Rapid Antibiotic Susceptibility Testing Platform For Direct Clinical Samples, Terrance Zhang

Honors Scholar Theses

Infectious diseases and septicemia are two of the major causes of death in the U.S., necessitating rapid treatment of septic patients with proper, efficacious antibiotics. Unfortunately, the emergence and spread of multidrug-resistant bacteria are continuously being aggravated by an abuse in antibiotic prescription at a clinical and agricultural level. It is known that antibiotic resistance evolves through the sequential accumulation of multiple mutations in bacteria, which is accentuated by prolonged exposure of bacteria to ineffective antibiotics when implementing traditional septicemia treatment. The goal of this project is to develop a novel, easy-to-use AST platform for rapid antimicrobial susceptibility profiling to …


Identification And Analysis Of Feather Degrading Bacteria: A Search For Keratinase Genes, Nehal Navali May 2020

Identification And Analysis Of Feather Degrading Bacteria: A Search For Keratinase Genes, Nehal Navali

Honors Scholar Theses

Over two million tons of feather waste is generated annually by the poultry industry, the majority of which goes into landfills due to the difficulty of degrading its major component keratin. Although a portion of feather waste is eliminated via incineration or chemical treatment, the use of Feather Degrading Bacteria (FDB) has been proposed as a cheap and eco-friendly alternative. FDBs have been consistently isolated from the feather microbiome of birds and contain genes coding for the specialized protein keratinase which is able to degrade feathers. By doing so, feather waste, which is rich in nutrients, can be repurposed as …


Toxicity Analysis Of 2’-Deoxyguanosine-N2-6-Aminopyrene And 2’-Deoxyguanosine-N2-8-Aminopyrene In Escherichia Coli, Emily Janeiro May 2020

Toxicity Analysis Of 2’-Deoxyguanosine-N2-6-Aminopyrene And 2’-Deoxyguanosine-N2-8-Aminopyrene In Escherichia Coli, Emily Janeiro

Honors Scholar Theses

Cancer is a disease that stems from genomic errors that are not corrected properly by cellular repair mechanisms. Errors are more likely to form when organisms are subjected to DNA damage by mutagenic compounds. 1-Nitropyrene, a nitrated polycyclic aromatic hydrocarbon (nitro-PAH), has been shown to be a potent mutagen that causes cancer. Nitro-PAHs can arise from diesel exhaust products in the environment. Out of all nitro-PAHs, 1-nitropyrene is found in largest quantities in the environment. This poses a great need to study its effects biochemically in order to address its toxicity in DNA. Other nitropyrene derivatives, including 1,6-dinitropyrene and 1,8-dinitropyrene, …


Identification Of Genes Conferring Acid Resistance In Vibrio Parahaemolyticus, Erin Gibbons May 2018

Identification Of Genes Conferring Acid Resistance In Vibrio Parahaemolyticus, Erin Gibbons

Honors Scholar Theses

Vibrio parahaemolyticus has the capability to be acid resistant due to known and unknown mechanisms. The goal of this project was to determine possible genes involved in conferring acid resistance of this bacterium. The vp1277 gene (designated as HA) and its downstream gene vp1999 were investigated for their role in acid resistance. Another potential gene that could contribute to acid resistance is vp0820 because of its similarity to the ToxR gene in Vibrio cholera. All three of these knockout strains and the wild type were grown in neutral LB and then tested with acidic LB’s of pH 4.5, 5, and …


Composition And Function Of The Bacterial Consortium Associated With The Accessory Nidamental Gland Of The Hawaiian Bobtail Squid, Jessica Bertenshaw May 2018

Composition And Function Of The Bacterial Consortium Associated With The Accessory Nidamental Gland Of The Hawaiian Bobtail Squid, Jessica Bertenshaw

Honors Scholar Theses

The bacterial consortium associated with the accessory nidamental gland (ANG) of the Hawaiian bobtail squid, Euprymna Scolopes is posited to confer symbiotic benefits to the eggs of the squid when bacteria are transferred from the gland of the mother to the jelly coat, which surrounds the embryo in the egg. To characterize the composition of this community bacterial isolates from the egg jelly coat and from the ANG were identified using 16S sequencing. To elucidate the function of these bacteria, egg development experiments were performed to determine the effect of antibiotics on egg survival and the composition of the bacterial …


Characterizing Cultivable Bacteria From Trachymyrmex Septentrionalis Fungus Gardens, Hannah Beatty May 2018

Characterizing Cultivable Bacteria From Trachymyrmex Septentrionalis Fungus Gardens, Hannah Beatty

Honors Scholar Theses

The relationship between the fungus-growing ant Trachymyrmex septentrionalis, its symbiotic cultivar fungus, and the transient and residential community of microorganisms is a diverse and complex symbiosis that has evolved over space and time. The fungus garden, comprised primarily of the cultivar fungus belonging to the family Leucocoprineae,provides an environment that hosts many bacteria, which may also play an important role in this symbiosis. Although it is known that Pseudonocardia bacteria defend the ant host against fungal pathogens, other species of bacteria that are present in these fungus gardens also likely contribute to this symbiosis. Previous studies of this …


Investigation Of Bacteria From The Trachymyrmex Septentrionalis Fungus Garden For Potential Antibacterial Drug Leads, Brendan Stewart Apr 2018

Investigation Of Bacteria From The Trachymyrmex Septentrionalis Fungus Garden For Potential Antibacterial Drug Leads, Brendan Stewart

Honors Scholar Theses

Bacterial and fungal strains are growing resistance to antibiotics and antifungal agents at an alarming rate. According to the Centers for Disease Control and Prevention, over two million people in the United States in 2016 were diagnosed with an infection resistant to antibiotics. As such, there has been increased interest in natural products as sources of novel compounds that are essential to the development of new drugs and treatment methods. Within the environment, there are various host-microbe symbioses, one of which is the Trachymyrmex septentrionalis leaf-cutter ant community. The microbes in symbioses like the T. septentrionalis community are hypothesized to …


Identification, Characterization, And Life Cycle Of Intein-Associated Homing Endonucleases, Joshua J. Skydel Jun 2016

Identification, Characterization, And Life Cycle Of Intein-Associated Homing Endonucleases, Joshua J. Skydel

Honors Scholar Theses

Inteins are molecular parasites that have been identified in unicellular organisms from the three domains of life. The intein self-excises following translation of the host gene, and therefore incurs a fitness cost for its carrier. The symbiotic state of the intein to its host is dependent on the presence or absence of a homing endonuclease domain, which facilitates horizontal transfer of the molecule. Identification of this domain provides information on the evolutionary history of the intein, as well as patterns of horizontal gene transfer in microbial communities. I have therefore developed Hidden Markov Models (HMMs) to identify homing endonuclease domains …


Contribution Of Probiotics Streptococcus Salivarius Strains K12 And M18 To Oral Health In Humans: A Review, Turner A. Stowik May 2016

Contribution Of Probiotics Streptococcus Salivarius Strains K12 And M18 To Oral Health In Humans: A Review, Turner A. Stowik

Honors Scholar Theses

The overgrowth and disequilibrium of pathogenic microorganism species both native and non-native to the oral cavity can manifest into a variety of different oral diseases, pathologies, and afflictions in humans, including dental caries, gingivitis, pharyngitis, halitosis, and oral candidiasis. Two bacterial strains with clinically-significant probiotic applications in curtailing the pathogenic bacterial growth involved in these conditions are Streptococcus salivarius strain K12 and Streptococcus salivarius strain M18. To summarize the most up-to-date in vitro, in vivo, and clinical research findings, administration of these S. salivarius strains typically in the form of probiotic lozenges results in colonization, reduction in inflammatory measures, …


The Efficacy Of Zinc And Manganese In Controlling Methicillin-Resistant Staphylococcus Aureus Wound Infections In Vitro, Patrick B. Lau May 2016

The Efficacy Of Zinc And Manganese In Controlling Methicillin-Resistant Staphylococcus Aureus Wound Infections In Vitro, Patrick B. Lau

Honors Scholar Theses

The emergence of Methicillin-Resistant Stapylococcus aureus has triggered an increased interest in finding alternative natural antimicrobials to control the pathogen and combat growing antibiotic resistance. This study investigated the antimicrobial effect of two naturally occurring essential minerals, zinc (Zn) and manganese (Mn) on MRSA for potential application in wound infections. The sub inhibitory concentration (SIC) and minimum inhibitory concentration (MIC) of Zn and Mn against MRSA were determined. The effect of MIC and 2x MIC of Zn and Mn in increasing MRSA susceptibility to oxacillin, and the effect of SIC and MIC of these minerals on MRSA cell adherence and …


Characterization Of Induced Rnai Silencing Of Vaccinia Virus Essential Genes, Kewa Jiang May 2016

Characterization Of Induced Rnai Silencing Of Vaccinia Virus Essential Genes, Kewa Jiang

Honors Scholar Theses

Vaccinia virus (VACV) is a large double-stranded DNA virus and the prototypical member of the family Poxviridae and is most notable for its use as the vaccine that eradicated smallpox (variola virus). More recently, VACV has been used to develop recombinant vaccines and immunotherapies. However, many of these processes require VACV replication to be tightly controlled. RNA interference (RNAi) is a powerful tool for in vitro silencing of mRNAs that are complementary to 19-21 base pairs (bp) of double-stranded RNA (dsRNA). This project outlines the design and preliminary analysis of two inducible RNAi silencing constructs targeting multiple VACV essential genes …


An Exploration Of The Phylogenetic Placement Of Recently Discovered Ultrasmall Archaeal Lineages, Jeffrey M. O'Brien Aug 2015

An Exploration Of The Phylogenetic Placement Of Recently Discovered Ultrasmall Archaeal Lineages, Jeffrey M. O'Brien

Honors Scholar Theses

In recent years, several new clades within the domain Achaea have been discovered. This is due in part to microbiological sampling of novel environments, and the increasing ability to detect and sequence uncultivable organisms through metagenomic analysis. These organisms share certain features, such as small cell size and streamlined genomes. Reduction in genome size can present difficulties to phylogenetic reconstruction programs. Since there is less genetic data to work with, these organisms often have missing genes in concatenated multiple sequence alignments. Evolutionary Biologists have not reached a consensus on the placement of these lineages in the archaeal evolutionary tree. There …


Chemical Profiling And Biological Activity Of Two Tunicate-Associated Marine Bacteria, Lyubina Yankova May 2014

Chemical Profiling And Biological Activity Of Two Tunicate-Associated Marine Bacteria, Lyubina Yankova

Honors Scholar Theses

Marine natural products have recently been an increasingly abundant source of novel antibiotics. Given that there is an increasing resistance to current drug therapies, finding new sources such as marine natural products is essential. Tunicate-associated marine bacteria can be a significant source of antibacterial compounds. Two tunicates of the species Eudistoma were collected from Portobelo National Park on the Salmedina Reef of Panama in the Caribbean Sea. Bacteria associated with the tunicate were isolated, cultured, extracted, and fractionated. Fractions were tested against an array of clinically relevant bacterial pathogens in the BioMAP assay. Two fractions MB0086E and MB0088E demonstrated activity …


In Vitro Characterization Of Avian Influenza Virus Isolates With A Truncated Ns1 Gene Segment, Aaron Dick May 2013

In Vitro Characterization Of Avian Influenza Virus Isolates With A Truncated Ns1 Gene Segment, Aaron Dick

Honors Scholar Theses

Avian Influenza Virus represents a significant threat to the world poultry population, and is a potential threat to humans due to the possibility of cross-species AIV infection. Our approach is to characterize a number of avian virus populations with respect to their content of biologically active particles that include hemagglutinating particles (HAP), plaque forming particles (PFP), interferon inducing particles (IFP), interferon induction-suppressing particles (ISP), defective-interfering particles (DIP), cell-killing particles (CKP) and non-infectious cell killing particles (niCKP) using unique in vitro assays developed for avian influenza virus in the Marcus-Sekellick Laboratory. Specifically, we will use a strain of Avian influenza virus, …


Macroh2a1 Regulation During The Cell Cycle Of Mouse Embryonic Stem Cells, Persis S. Thomas May 2010

Macroh2a1 Regulation During The Cell Cycle Of Mouse Embryonic Stem Cells, Persis S. Thomas

Honors Scholar Theses

MacroH2A is a core histone variant that plays an important role in the X-inactivation process during differentiation of embryonic stem cells. It has been shown that macroH2A changes in localization during the cell cycle of somatic cells. This study aims to determine how macroH2A changes during the cell cycle of embryonic stem cells. Male and female mouse embryonic stem cells were transfected with a GFP::macroH2A construct and the relationship between macroH2A and the cell cycle was determined using FACS. This study shows that macroH2A is altered during the cell cycle of embryonic stem cells as it is in somatic cells …


In Vitro Expression And Purification Of Class I Mhc Molecules, Loi Cheng May 2006

In Vitro Expression And Purification Of Class I Mhc Molecules, Loi Cheng

Honors Scholar Theses

The major histocompatibility complex (MHC) is a gene family responsible for many critical functions of the immune system in most vertebrates. The MHC consists of three classes differentiated by their structure and function, and MHC class I encodes antigen binding proteins as well as chaperone and accessory proteins such as tapasin. The purpose of this project is to reconstitute several human MHC class I molecules in their peptide-filled and peptide-deficient forms, and to purify these proteins for biochemical study. The expressed proteins include wild type and mutant variants of the fusion protein human leukocyte antigen HLA-B*0801-fos, and human beta-2-microglobulin (β2m). …