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Investigating The Impact Of Nonenzymatic Lysine Acetylation On The Function Of The Bacterial Ribosome, Sarah Caldwell Feid Jan 2023

Investigating The Impact Of Nonenzymatic Lysine Acetylation On The Function Of The Bacterial Ribosome, Sarah Caldwell Feid

Dissertations

An under-investigated target of lysine acetylation is the bacterial ribosome. Although lysine acetylations on the ribosome are common and conversed in diverse bacterial species, little work has been done to understand how lysine acetylation affects the bacterial ribosome. The goal of this work is to determine if lysine acetylation has functional impact on the bacterial ribosome.I have identified in vitro and in vivo effects of nonenzymatic, AcP-dependent lysine acetylation on translation and the ribosome. In vitro acetylation of transcription-translation reactions causes a translation-specific defect that is unaffected by the addition of the CobB deacetylase. This suggests certain AcP-sensitive residues that …


Characterization Of Mroq-Dependent Regulation Of Staphylococcus Aureus Quorum Sensing, Madison Ruth Stock Jan 2023

Characterization Of Mroq-Dependent Regulation Of Staphylococcus Aureus Quorum Sensing, Madison Ruth Stock

Dissertations

Gram-positive bacteria produce small autoinducing peptides (AIPs), which act to regulate expression of genes that promote adaptive traits including virulence. The Gram-positive pathogen Staphylococcus aureus generates a cyclic AIP that controls expression of virulence factors via the accessory gene regulatory (Agr) system. S. aureus strains belong to one of four Agr groups (I, II, III, and IV), and each group harbors allelic variants of AgrD, the precursor of AIP. In a prior screen for S. aureus virulence factors, the Alonzo lab identified MroQ, a putative peptidase. A ΔmroQ mutant closely resembled a Δagr mutant and had significant defects in AIP …


Identification Of Conditions That Promote Biofilm Formation By Vibrio Fischeri And Elucidation Of The Underlying Signal Transduction Pathway, Courtney Noelle Dial Jan 2023

Identification Of Conditions That Promote Biofilm Formation By Vibrio Fischeri And Elucidation Of The Underlying Signal Transduction Pathway, Courtney Noelle Dial

Dissertations

Biofilms are communities of microorganisms that have intrinsically antimicrobial properties and are difficult to treat in the clinical setting. The marine bacterium Vibrio fischeri efficiently colonizes its symbiotic squid host, Euprymna scolopes, by producing a transient biofilm dependent on the symbiosis polysaccharide (SYP), making it the perfect model system to study biofilm dynamics. In vitro, however, wild-type (WT) strain ES114 fails to form SYP – dependent biofilms. Instead, genetically engineered strains, such as those lacking the negative regulator BinK, have been developed to study SYP biofilms. Historically, V. fischeri has been grown using LBS, a complex medium containing tryptone and …


Identification Of New Substrates From Pseudomonas Aeruginosa Exos, Adam V. Thota Jan 2023

Identification Of New Substrates From Pseudomonas Aeruginosa Exos, Adam V. Thota

Master's Theses

Pseudomonas aeruginosa is a gram-negative environmental bacterium that uses its intrinsic and acquired antibiotic resistance to infect patients with compromised epithelium, such as cystic fibrosis and burn wounds, and corneal keratitis. In order to cause disease, most strains of P. aeruginosa use the type three secretion system (T3SS) to disrupt cellular signaling and integrity. However, P. aeruginosa may also secrete exotoxins after invading host cells, which prolongs host cell death and maintains an intracellular niche. Of the T3 secreted effector toxins, ExoS, specifically the ADP-ribosyltransferase activity of ExoS, was shown to delay the death of invaded corneal cells, but it …


Interrogating Antagonistic Differences Among Pseudomonas Aeruginosa Cdia Alleles, Haotian Yang Oct 2022

Interrogating Antagonistic Differences Among Pseudomonas Aeruginosa Cdia Alleles, Haotian Yang

Master's Theses

Bacteria are complex social organisms that live within mixed communities where microorganisms compete for limited resources. We studied Contact-Dependent Growth Inhibition (CDI), a particular type of competition mediated by a type 5b, or two-partner, secretion system that is widely spread among Gram-negative bacteria. CdiB and CdiA make up the two-partner secretion system that mediates CDI. CdiB translocates CdiA to the cell surface, and CdiA delivers its C-terminal toxin domain to the target cell. The C-terminal toxin (Tox) domain of CdiA is highly diverse. We studied Tox domains of various Pseudomonas aeruginosa clinical isolates. We found different strains that contain unique …


Role Of Tetraspanins In Sars-Cov-2 Fusion And Entry, Marcos Saul Santiago Figueroa Oct 2022

Role Of Tetraspanins In Sars-Cov-2 Fusion And Entry, Marcos Saul Santiago Figueroa

Master's Theses

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the pandemic the world has been facing in recent years. Even as new countermeasures are developed, there is still much we don’t know in terms of its entry into host cells. Tetraspanins are transmembrane proteins that are near ubiquitous amongst cell types. They fulfill numerous roles, including that of a viral co-receptor. Here, we considered whether tetraspanins, specifically CD9, CD63, and CD81 influence SARS-CoV-2 fusion and entry. Using ACE2-LgBit and tetraspanin overexpressing EVs and HeLa cells, we find that the presence of excess tetraspanins inhibit fusion and entry. However, we …


Calcium-Mediated Induction Of Vibrio Fischeri Es114 Biofilms, Katia Elizabeth Semenchuk Jan 2022

Calcium-Mediated Induction Of Vibrio Fischeri Es114 Biofilms, Katia Elizabeth Semenchuk

Master's Theses

Vibrio fischeri bacteria form biofilms that facilitate symbiotic colonization of the Hawaiian bobtail squid, Euprymna scolopes. These host-associated biofilms require production of the SYP polysaccharide. However, it has been difficult to observe robust biofilm formation in vitro in a laboratory setting using wild-type strain ES114; instead, most work investigating syp-dependent biofilm formation has relied on genetically altered strains. Guided by recent findings that increasing calcium induces c-di-GMP (Tischler et al., 2021), a molecule known in other systems to promote biofilm formation, the question was posed as to whether high levels of calcium alone could promote syp-dependent biofilm formation by ES114. …


Bisacodyl Limits Chikungunya Virus In Vitro And Is Broadly Antiviral, Natalie June Lomascolo Jan 2022

Bisacodyl Limits Chikungunya Virus In Vitro And Is Broadly Antiviral, Natalie June Lomascolo

Master's Theses

Identifying novel antivirals requires significant time and resource investment, and the continuous threat of viruses to human health necessitates commitment to antiviral identification and development. Developing antivirals requires years of research and validation, and recent outbreaks have highlighted the need for preparedness in counteracting pandemics. One way to facilitate development is to repurpose molecules already used clinically. By screening such compounds, we can accelerate antiviral development. Here, we screened compounds from the National Institutes of Health’s Developmental Therapeutic Program for activity against chikungunya virus, an alphavirus that is responsible for a significant outbreak in the Americas in 2013. Using this …


Investigating The Role Of Nagc Reveals It To Be A Global Regulator, Natasha Peterson Jan 2022

Investigating The Role Of Nagc Reveals It To Be A Global Regulator, Natasha Peterson

Master's Theses

Bacterial colonization of host surfaces can result in symbiotic or pathogenic associations.As bacteria becomes more resistant to antibiotics, pathogenic bacterial colonization poses an increasing risk to human health. Symbiotic associations that have beneficial outcomes for both the host and the microbe can serve as models to investigate how bacterial processes affect colonization of host surfaces. The symbiotic relationship between the Gram-negative, bioluminescent bacterium Vibrio fischeri and the Hawaiian bobtail squid is one such model (E. V. Stabb & Visick, 2013). The study of this exclusive relationship has developed in a way where in vitro phenotypes can predict the ability of …


Investigating The Roles Of Lipids In Staphylococcus Aureus Infection, Xi Chen Jan 2021

Investigating The Roles Of Lipids In Staphylococcus Aureus Infection, Xi Chen

Dissertations

The Gram-positive bacterium Staphylococcus aureus is a major threat to public health and causes a multitude of infections, ranging from mild skin and soft infection, to more severe diseases including sepsis, osteomyelitis and infective endocarditis. As a successful pathogen, S. aureus employs various mechanisms to invade host tissues, evade immune responses, and survive in the host environment. One critical adaptive trait of S. aureus that promotes virulence and survival is the ability to maintain membrane homeostasis via flexible modifications to its lipid composition in response to the surrounding lipid environment. Phospholipids are the major component of the bacterial membrane and …


F Plasmids In Escherichia Coli Decrease Permissivity To Coliphage, Cesar Eber Montelongo Hernandez Jan 2021

F Plasmids In Escherichia Coli Decrease Permissivity To Coliphage, Cesar Eber Montelongo Hernandez

Dissertations

The urinary tract contains a community of bacteria called the urinary microbiota (urobiota) thatmay be relevant to health; the genomic component of the urobiota is the urinary microbiome (urobiome). Urinary bacteria have been associated with both asymptomatic states and disease conditions, such as urinary tract infection (UTI), overactive bladder (OAB), and urge urinary incontinence (UUI). Some bacteria, such as E. coli, are considered urinary pathogens (uropathogens) but also can be commensals. Bacteriophage (phage) are ubiquitous in nature and likely shape bacterial populations in every niche; thus, phage may be one factor that modulates the urobiota. Phages have a specific host …


Identification And Characterization Of Calcium As A Biofilm Promoting Signal By Vibrio Fischeri, Alice Hannah Tischler Jan 2021

Identification And Characterization Of Calcium As A Biofilm Promoting Signal By Vibrio Fischeri, Alice Hannah Tischler

Dissertations

The marine bacterium, V. fischeri actively engages in an exclusive partnership in the light organ of its squid host, Euprymna scolopes. A critical step in this colonization process is the formation of a bacterial aggregate, or biofilm, which is a community of bacteria embedded within a protective extracellular matrix. While V. fischeri readily forms biofilms in nature, genetic overexpression must be utilized to achieve biofilm formation in the laboratory. Recent work investigating media composition led myself and others to evaluate how seawater salts impacted growth and biofilm formation in a number of mutant backgrounds, leading to the identification of calcium …


Chga-Depleted Urothelial Amp And Immune Response During Urinary Tract Infection, Theadora Jane Ceccarelli Jan 2021

Chga-Depleted Urothelial Amp And Immune Response During Urinary Tract Infection, Theadora Jane Ceccarelli

Master's Theses

Women are 8 times more likely than men to experience a urinary tract infection (UTI) with up to 60% of women reporting a UTI in their lifetime. This significant healthcare burden is caused by the infection of uropathogenic Escherichia coli in the urinary tract. At this time, treatment is limited to antibiotic therapy, which is challenged by antibiotic-resistance. These factors make UTIs an NIH priority and are motivation for our research.CgA is a protein of the granin family co-released with catecholamines from neuroendocrine cells throughout the body. Pro-hormone convertases post-translationally cleave CgA into peptides, like catestatin, which can have antimicrobial …


Elucidating Regulatory Connections Between The Second Messenger Cyclic-Di-Gmp With Biofilm And Motility Phenotypes Of Vibrio Fischeri, Ali Razvi Jan 2021

Elucidating Regulatory Connections Between The Second Messenger Cyclic-Di-Gmp With Biofilm And Motility Phenotypes Of Vibrio Fischeri, Ali Razvi

Master's Theses

The symbiosis between the gram-negative marine bacterium Vibrio fischeri and its host Euprymna Scolopes occurs when the bacteria reaches and colonizes the light organ. This pathway to colonization begins in the outer marine environment and finishes within the deep crypts of the light organ, with states of biofilm formation and dispersal in between. This switch between biofilm formation to dispersal is important as the bacteria transitions from the surface on the light organ into a pore leading to the interior of the light organ. This dispersal is regulated by LAP system which is dependent on the second messenger c-di-GMP. Through …


Characterizing A Novel Cocksackievirus B3 Protease Mutant And Its Response To Polyamine Depletion, Bridget Hulsebosch Jan 2021

Characterizing A Novel Cocksackievirus B3 Protease Mutant And Its Response To Polyamine Depletion, Bridget Hulsebosch

Master's Theses

Enteroviruses, including Coxsackievirus B3 (CVB3), are pervasive pathogens that cause significant disease, including cardiomyopathies. Unfortunately, no treatments or vaccines are available for infected individuals. We identified the host polyamine pathway as a potential drug target, as inhibiting polyamine biosynthesis significantly reduces enterovirus replication in vitro and in vivo. Here, we show that CVB3 is sensitive to polyamine depletion through the polyamine analog diethylnorspermidine (DENSpm) which enhances polyamine catabolism through induction of polyamine acetylation. We demonstrate that CVB3 acquires resistance to DENSpm via mutation of the 2A protease, which enhances proteolytic activity in the presence of DENSpm. Resistance to DENSpm occurred …


Assessing The Role Of The Interaction Between Polyamines And Heparan Sulfate In Coxsackievirus B3 Viral Infection, Oreoluwa Omoba Jan 2021

Assessing The Role Of The Interaction Between Polyamines And Heparan Sulfate In Coxsackievirus B3 Viral Infection, Oreoluwa Omoba

Master's Theses

Non-polioenteroviruses are highly infectious viruses that typically cause mild asymptomatic cases but can cause severe disease such as aseptic meningitis and dilated cardiomyopathy. Coxsackievirus B3 (CVB3) is a member of this group and is prevalent in the United States and Eastern Asia. Viruses like CVB3 rely on the host cell for many molecules in order to replicate. One such set of molecules is the polyamines. Polyamines are small, positively charged molecules that play a role in a multitude of cellular processes including RNA/DNA stabilization, gene expression, translation, and regulating membrane fluidity. Previous studies have shown CVB3 relies on polyamines for …


Zika Virus Inactivates Polyamine Catabolism Via Alternative Splicing To Enhance Infection, Marion Lea Graham Jan 2020

Zika Virus Inactivates Polyamine Catabolism Via Alternative Splicing To Enhance Infection, Marion Lea Graham

Master's Theses

During viral infection, the virus and host must compete for resources inside the cell. One of these resources is polyamines. Polyamines are small, positively charged molecules that are found in all eukaryotic cells. They play a key role in several cellular functions including growth and proliferation, transcription and translation, and membrane stability. Viruses also rely polyamines for productive replication, utilizing them during DNA/RNa polymerization, nucleic acid packaging, and protein synthesis. in response to a virus infecting a host cell, the host cell will begin to regulate polyamine levels as a way to combat the infection. Polyamine levels are regulated by …


Investigating The Mechanism Of The Coronavirus Endoribonuclease In Antagonizing Innate Immune Signaling, Matthew Hackbart Jan 2020

Investigating The Mechanism Of The Coronavirus Endoribonuclease In Antagonizing Innate Immune Signaling, Matthew Hackbart

Dissertations

Coronaviruses (CoVs) are positive-sense RNa viruses that can emerge from endemic reservoirs and infect zoonotically, causing significant morbidity and mortality. CoVs encode an endoribonuclease (EndoU) that cleaves RNa in biochemical assays, but the target and function of EndoU activity during viral replication was not known. My work focused on characterizing the functions of EndoU during infection. I report that EndoU is an innate immune antagonist. to function as an immune antagonist, EndoU cleaves the 5'-Poly-Uridines from Negative-sense viral RNA, termed PUN RNA, which is the product of polyA-templated RNa synthesis. Using a virus containing an EndoU catalytic-inactive mutation, I detected …


Elucidating The Impact And Mechanism Of Hepatitis C Virus Cell-To-Cell Spread, Karina Durso-Cain Jan 2020

Elucidating The Impact And Mechanism Of Hepatitis C Virus Cell-To-Cell Spread, Karina Durso-Cain

Dissertations

Virus cell-to-cell spread has been implicated in the establishment of persistent infection and has been shown to be involved in the transmission of antiviral resistant mutants. However, relatively little is known about how virus cell-to-cell spread impacts infection or the specific mechanisms by which cell-to-cell spread occurs. as such, this dissertation focused on investigating HCV cell-to-cell spread not only to learn more about this medically important virus, but also to determine the broader impact cell-to-cell spread has on viral infection dynamics, identify the cellular factors involved, and perhaps ultimately provide insight into antiviral strategies that might enhance the barrier to …


Distinct Roles For Carbohydrate And Protein Receptors In Coronavirus Infection, Enya Qing Jan 2020

Distinct Roles For Carbohydrate And Protein Receptors In Coronavirus Infection, Enya Qing

Dissertations

Coronaviruses (CoVs) are common human and animal pathogens. in humans, four endemic CoV species together account for one third of mild respiratory infections worldwide. More severe and frequently fatal respiratory pathologies are caused by recent CoV outbreaks that resulted from occasional zoonotic spillover from animal CoV reservoirs, namely, SARS-CoV in 2002, MERS-CoV in 2012, and SARS-CoV-2 in 2019. Because CoVs threaten global health, any chance of relieving CoV's threat on human populations would rely heavily on our understanding of the mechanistic requirements for CoV tropism, whose major determinant is at the level of viral entry. CoVs have evolved to use …


Elucidating The Targets And Function Of The Mlr Compass-Like Complex During Development, David Joseph Ford Jan 2020

Elucidating The Targets And Function Of The Mlr Compass-Like Complex During Development, David Joseph Ford

Dissertations

MLR COMPASS-like complexes are highly-conserved epigenetic regulators required for enhancer establishment and subsequent reprogramming during differentiation and development. Mutation of MLR complex subunits in humans is associated with cancer and developmental disorder, yet much remains to be determined concerning both the healthy and disease-altered functions of these complexes. Using the developmental model Drosophila melanogaster, I further elucidate the functions of the MLR complex during in vivo organ development as well as stress response. I characterize the miRNa bantam as a regulatory target of the complex, required for proper tissue patterning during wing and compound eye formation. in the same systems …


Investigating The Role Of Hypusine In Viral Translation And Infection, Jeremy Joseph Esin Jan 2020

Investigating The Role Of Hypusine In Viral Translation And Infection, Jeremy Joseph Esin

Master's Theses

Polyamines are small, positively charged, molecules found in eukaryotic cells with roles in cellular function and viral infection. in previous work we have shown RNa viruses, including bunyaviruses, to be sensitive to polyamine depletion, but exact mechanisms are unknown. Bunyaviruses are emerging pathogens that cause encephalitis, hemorrhagic fevers, and meningitis. Rift Valley Fever Virus is a bunyavirus that infects both humans and livestock with severe mortality and morbidity. in previous work done with Rift Valley Fever Virus polyamine depleted results in noninfectious interfering particles without affecting the shape or size of the particles. Here, I investigate a specific metabolic pathway …


A Susceptibility Study Of Urinary Isolates To Methenamine Hippurate And Its Metabolites, Nancy Sloan Jan 2020

A Susceptibility Study Of Urinary Isolates To Methenamine Hippurate And Its Metabolites, Nancy Sloan

Master's Theses

Urinary Tract Infection (UTI) is one of the most common bacterial infections in adult women. Treatment is one of the most common reasons for antibiotic prescription. the rise of antibiotic-resistant infections coupled with the shortage of new antibiotics creates an urgent need for alternative non-antibiotic treatments. One alternative is methenamine hippurate (MH), which is a non-antibiotic prophylaxis. It is reported to be active against some common uropathogens including Escherichia coli and Enterococcus species, but its effects on the newly discovered bladder microbiota (urobiome) are undocumented. Given this knowledge gap, this study aimed to evaluate the drug's spectrum of susceptibility on …


Determining Interactions Between Bacteriophage And Urinary Microbiome Lysogens, Michael Bochert Jan 2020

Determining Interactions Between Bacteriophage And Urinary Microbiome Lysogens, Michael Bochert

Master's Theses

Bacteriophages (phages) are viruses that infect bacteria. They are the most abundant life forms on earth. It is estimated that there are approximately 10³⁰ phages on the planet (Chibani-Chennoufi et al. 2004). They outnumber their bacterial hosts approximately 10 to 1. Bacteria inhabit most niches on the planet including the human body, where they play critical roles in health and disease. Since phages shape bacterial populations the same way that viruses, such as smallpox and measles, shaped human populations, it is important to understand how they interact with their bacterial hosts. The majority of the phages that we know of …


Characterization Of The Φctx-Like Pseudomonas Aeruginosa Phage Dobby Isolated From The Kidney Stone Microbiota, Genevieve Johnson, Alan J. Wolfe, Catherine Putonti Mar 2019

Characterization Of The Φctx-Like Pseudomonas Aeruginosa Phage Dobby Isolated From The Kidney Stone Microbiota, Genevieve Johnson, Alan J. Wolfe, Catherine Putonti

Biology: Faculty Publications and Other Works

Bacteriophages (phages) are vital members of the human microbiota. They are abundant even within low biomass niches of the human body, including the lower urinary tract. While several prior studies have cultured bacteria from kidney stones, this is the first study to explore phages within the kidney stone microbiota. Here we report Dobby, a temperate phage isolated from a strain of Pseudomonas aeruginosa cultured from a kidney stone. Dobby is capable of lysing clinical P. aeruginosa strains within our collection from the urinary tract. Sequencing was performed producing a 37 152 bp genome that closely resembles the temperate P. aeruginosa …


Modulation Of Coxsackievirus Protease Activity By Polyamines, Courtney Noelle Dial Jan 2019

Modulation Of Coxsackievirus Protease Activity By Polyamines, Courtney Noelle Dial

Master's Theses

Coxsackievirus type B (CVB3) is one of the six serotypes of the Coxsackievirus family of non-enveloped, linear, and positive-sense single-stranded RNA viruses. It is a pathogenic enterovirus that belongs to the same genus as the notable pathogen poliovirus. CVB3 can cause a range of illnesses from a fever to gastrointestinal distress but is most noteworthy for the ability to cause viral myocarditis, a swelling of the heart muscle. Coxsackievirus, like all RNA viruses, tends to develop mutations rapidly due to its error prone polymerase and lack of proofreading activity. These mutations can be advantageous for the virus, allowing it to …


The Role Of Polyamines In Enteroviral Attachment, Thomas Mckenzie Kicmal Jan 2019

The Role Of Polyamines In Enteroviral Attachment, Thomas Mckenzie Kicmal

Master's Theses

Polyamines are small polycationic molecules with flexible carbon chains that are found in all eukaryotic cells. Polyamines are involved in the regulation of many host processes and have been shown to be implicated in viral replication. Depletion of polyamine pools in cells with FDA approved drugs restricts replication of diverse RNA viruses. Viruses can exploit host polyamines to facilitate packaging, transcription, translation, and protease activity but other mechanisms remain largely unknown. Picornaviruses, including Coxsackievirus B3 (CVB3), are sensitive to depletion of polyamines and remain a significant public health threat. We employed CVB3 as a model system to investigate a potential …


Regulation Of Acetyl Phosphate-Dependent Acetylation And Identification Of Novel Lysine Acetyltransferases In Escherichia Coli, David George Christensen Jan 2019

Regulation Of Acetyl Phosphate-Dependent Acetylation And Identification Of Novel Lysine Acetyltransferases In Escherichia Coli, David George Christensen

Dissertations

Over billions of years, organisms have organized chemical reactions into metabolic pathways to sustain life. However, metabolic substrates can undergo many uncatalyzed, extra-metabolic reactions. Acetyl phosphate (AcP), an intermediate of the acetate fermentation pathway in E. coli, is one such metabolite that has been shown to non-enzymatically acetylate hundreds of proteins. This diverse set of targets suggests that acetylation could be a way for the cell to sense its nutritional status and regulate protein activity accordingly. However, how E. coli regulates acetylation, if at all, is unknown.Previous work showed that acetylation becomes pronounced in stationary phase cells. I determined that …


Membrane Microdomains As Platforms For Extra-Cellular Fusions, Michael Hantak Jan 2019

Membrane Microdomains As Platforms For Extra-Cellular Fusions, Michael Hantak

Dissertations

Life requires biological membranes. Membrane-enclosed compartments separate and unite through dynamic fission and fusion reactions. These are catalyzed processes that are central in organismal biogenesis. This dissertation focuses on extracellular membrane fusions, which are central to several processes. (1) Enveloped viruses enter cells through membrane fusions. (2) Extracellular vesicles (EVs) also deliver molecules into cells through membrane fusions. (3) Entire cells also fuse together, generating fertilized zygotes, skeletal muscles, and giant cell macrophages.Mechanisms of extracellular membrane fusion are poorly understood. This dissertation aimed to further define these mechanisms. We focused on regulatory cofactors, including tetraspanins, transmembrane proteins that cluster into …


Staphylococcus Aureus Evasion Of The Innate Immune System, James Paul Grayczyk Jan 2019

Staphylococcus Aureus Evasion Of The Innate Immune System, James Paul Grayczyk

Dissertations

Upon entry into the host, pathogens must overcome innate immunity in order to cause disease. The innate immune system represents a fast-acting initial line of defense to prevent infection. In order to withstand innate defenses, bacterial pathogens like the Gram-positive bacterium Staphylococcus aureus, produce a wide array of virulence factors that can inhibit innate immune cell recruitment and antimicrobial activity, or directly target and kill phagocytic leukocytes thereby facilitating pathogenesis. Infection with S. aureus can cause disease in virtually any tissue site and is a significant burden to human health. In this dissertation, we sought to understand how S. aureus …