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Full-Text Articles in Medical Microbiology

The Role Of Coagulase-Negative Staphylococcal Secreted Products On Staphylococcus Aureus And Staphylococcus Lugdunensis Infections, Denny Chin Apr 2022

The Role Of Coagulase-Negative Staphylococcal Secreted Products On Staphylococcus Aureus And Staphylococcus Lugdunensis Infections, Denny Chin

Electronic Thesis and Dissertation Repository

The Staphylococcus genus is comprised of over 40 bacterial species. The most well-studied species in this genus is the notorious human pathogen Staphylococcus aureus, a bacterium that produces coagulase among many other virulence factors. Since S. aureus is a major health burden and causes a plethora of diseases in humans, it has received significant attention and much research has been done to understand its biology to treat diseases caused by this pathogen. However, the coagulase-negative staphylococci (CoNS) make up most of the staphylococcal species and have received less attention since they are thought to have a lesser impact on …


Hiv-1 Drug Resistance To Integrase Strand Transfer Inhibitors In Hiv-1 Non-B Subtypes, Emmanuel Ndashimye Apr 2021

Hiv-1 Drug Resistance To Integrase Strand Transfer Inhibitors In Hiv-1 Non-B Subtypes, Emmanuel Ndashimye

Electronic Thesis and Dissertation Repository

Human immunodeficiency syndrome (HIV-1) has infected over 75 million people and over 35 million have succumbed to virus related illnesses. Despite access to a variety of antiretroviral therapy (ART) options, ART programs have been disproportionally spread in the world with low-and middle-income countries (LMICs) facing challenges to access the most potent ART options. With less potent ART remaining in use in LMICs, HIV-1 drug resistance (HIVDR) presents a growing challenge in LMICs. Since approval of the first-generation integrase strand transfer inhibitor (INSTIs), Raltegravir (RAL) in 2007, INSTIs remain the best choice as a backbone of ART. Access to second generation …


Potential Role Of Extracellular Atp Released By Bacteria In Bladder Infection And Contractility, Behnam Abbasian Apr 2019

Potential Role Of Extracellular Atp Released By Bacteria In Bladder Infection And Contractility, Behnam Abbasian

Electronic Thesis and Dissertation Repository

Urgency urinary incontinence (UUI), the result of conditions such as overactive bladder (OAB), could potentially be influenced by both commensal and urinary tract infection-associated bacteria. The sensing of bladder filling involves interplay between various parts of the nervous system eventually resulting in contraction of the detrusor muscle during micturition. Here we model host responses to various urogenital bacteria, firstly by using urothelial bladder cell lines and then with myofibroblast contraction assays. To measure responses, we examined calcium influx, gene expression and alpha smooth muscle actin deposition assays. We found that organisms such as Escherichia coli IA2 and Gardnerella vaginalis ATCC …


Understanding The Impact Of Hiv-1 Genetic Diversity On The Function Of Nef And Its Role In Serinc5 Antagonism, Aaron Leslie Johnson Aug 2018

Understanding The Impact Of Hiv-1 Genetic Diversity On The Function Of Nef And Its Role In Serinc5 Antagonism, Aaron Leslie Johnson

Electronic Thesis and Dissertation Repository

HIV-1 Nef is a key pathogenic protein, allowing HIV-1 to evade the host immune system by downregulating MHC-I and CD4. Furthermore, it was recently discovered that Nef counteracts the host factor SERINC5 to increase HIV-1 infectivity, but the mechanistic details of the Nef:SERINC5 interaction still need to be explored. Throughout this dissertation, I will explore the hypothesis that the genetic diversity that defines HIV-1 has a pronounced effect on the HIV-1 protein Nef, altering its function between and within group M subtypes. To address this hypothesis I investigated how MHC-I and CD4 downregulation differ among all non-recombinant group M subtypes. …


Characterization Of The Atsr/Atst Global Regulatory Pathway In Burkholderia Ceocepacia, Maryam Khodai-Kalaki Aug 2015

Characterization Of The Atsr/Atst Global Regulatory Pathway In Burkholderia Ceocepacia, Maryam Khodai-Kalaki

Electronic Thesis and Dissertation Repository

Phosphorylation cascades governed by two-component signal transduction systems provide key signalling mechanisms in bacteria, simple eukaryotes and higher plants, allowing them to translate signals into adaptive responses. These regulatory pathways consist of a transmembrane sensor protein that responds to an environmental cue leading to autophosphorylation, followed by the transfer of the phosphate to a cytoplasmic response regulator. Here, I study AtsR, a membrane-bound hybrid sensor kinase of Burkholderia cenocepacia, that negatively regulates quorum sensing related virulence factors such as biofilm, type 6-secretion and protease secretion. B. cenocepacia is a Gram-negative opportunistic pathogen which causes severe, chronic respiratory infections in …


Granulocyte Colony-Stimulating Factor: Its Role In Gut-Homing Macrophage Generation And Colitis, And Production By Probiotics, Shahab Meshkibaf May 2015

Granulocyte Colony-Stimulating Factor: Its Role In Gut-Homing Macrophage Generation And Colitis, And Production By Probiotics, Shahab Meshkibaf

Electronic Thesis and Dissertation Repository

The pleiotropic cytokine granulocyte-colony stimulatory factor (G-CSF) is mainly required for the generation of neutrophils, but its role in macrophage generation has also been reported. In addition, G-CSF is effective for the down-regulation of inflammatory cytokines and ameliorating gut disorders, such as colitis. However, the G-CSF function in macrophage generation and gut immunity remains unclear. The first focus of this thesis was to assess the role of G-CSF in macrophage generation and its contribution to gut immunity. G-CSF was found to promote the generation of Gr-1high/F4/80+ macrophages in macrophage (M)-CSF-treated bone marrow cells, most likely through suppressing cell death. Gr-1high …


Systematic Assessment Of The Contribution Of Superantigens To Nasopharyngeal Colonization In A Mouse Model Of Streptococcal Infection, Katherine J. Kasper Jan 2013

Systematic Assessment Of The Contribution Of Superantigens To Nasopharyngeal Colonization In A Mouse Model Of Streptococcal Infection, Katherine J. Kasper

Electronic Thesis and Dissertation Repository

Streptococcus pyogenes is adapted for persistence in humans. It typically colonizes the tonsils and skin, and humans are the only known reservoir. S. pyogenes can cause a wide range of mild to serious infections. Most streptococci-related deaths are due to complications of rheumatic fever and invasive infections. S. pyogenes produces virulence factors that contribute to the pathogen’s ability to colonize and cause disease, including streptococcal superantigens (SAgs), also known as streptococcal pyrogenic exotoxins (Spes). SAgs function by cross-linking T cells and antigen presenting cells (APC) which may cause a massive inflammatory response, and as such have been found to contribute …