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Full-Text Articles in Pathogenic Microbiology
Tetr Family Regulator Farr Variation Controls Antimicrobial Fatty Acid Efflux In Staphylococcus Aureus, Camryn M. Bonn
Tetr Family Regulator Farr Variation Controls Antimicrobial Fatty Acid Efflux In Staphylococcus Aureus, Camryn M. Bonn
Electronic Thesis and Dissertation Repository
To colonize human skin and survive within abscesses, Staphylococcus aureus has evolved mechanisms to evade host innate defenses. USA300 has become the predominate community-acquired methicillin-resistant S. aureus (CA-MRSA) clone, which can be in part attributed to detoxification of unsaturated free fatty acids (uFFA) found in sebum and the nares. Our lab has previously identified the TetR family regulator FarR responsible for induction of the resistance-nodulation-division (RND) superfamily efflux pump FarE to promote efflux of toxic uFFA. However, RND family efflux pumps remain poorly characterized in Gram-positive species and the mechanism by which FarR regulates FarE has yet to be determined. …
The Surreptitious Survival Of The Emerging Pathogen Staphylococcus Lugdunensis In Macrophages Enhances S. Aureus Infection, David Watson
The Surreptitious Survival Of The Emerging Pathogen Staphylococcus Lugdunensis In Macrophages Enhances S. Aureus Infection, David Watson
Electronic Thesis and Dissertation Repository
Staphylococcus lugdunensis is an opportunistic pathogen that can cause invasive infections suggesting an ability to circumvent host immunity. S. lugdunensis was shown to resist killing and persist within macrophages and acetylation of its peptidoglycan is important for this survival. This was consistent in vivo, as S. lugdunensis resides inside Kupffer cells for at least 16 hours post-infection in mice. Despite its capability for survival, S. lugdunensis is unable to replicate within phagolysosomes. Inhibiting phagolysosomal effectors allows S. lugdunensis to initiate replication, after which the bacteria escape phagosomal containment. Moreover, intracellular S. lugdunensis augments the growth S. aureus during co-infection. Eight …
Iron And Copper Homeostasis In Staphylococcus Aureus, Holly A. Laakso
Iron And Copper Homeostasis In Staphylococcus Aureus, Holly A. Laakso
Electronic Thesis and Dissertation Repository
All microorganisms require transition metals for key metabolic processes, thus during infection microbial access to essential metals is tightly regulated by the host in a process termed nutritional immunity. Iron acquisition is critical to the pathogenesis of the formidable human pathogen, Staphylococcus aureus, which utilizes heme-uptake systems and two high-affinity iron-scavenging siderophores, staphyloferrin A (SA) and staphyloferrin B (SB) for iron acquisition. In this study, I identify sbnI as encoding a transcription factor required for expression of genes in the sbn operon, the biosynthetic operon for SB synthesis. I also show that SbnI is a novel hemoprotein, where binding …
Examination Of Bcaa Transport And Synthesis In Staphylococcus Aureus, Julienne Kaiser
Examination Of Bcaa Transport And Synthesis In Staphylococcus Aureus, Julienne Kaiser
Electronic Thesis and Dissertation Repository
Staphylococcus aureus is a human pathogen capable of causing infections that range from mild skin and soft tissue infections to severe infections of the bone, muscle, heart, and lung. To survive and thrive in such diverse host environments, S. aureus must maintain sufficient levels of metabolites and cofactors to support virulence determinant production and replication. The branched-chain amino acids (BCAAs; Ile, Leu, Val) represent an important group of nutrients for S. aureus metabolism, as they are required for protein synthesis and synthesis of membrane branched-chain fatty acids (BCFAs), which are important for S. aureus environmental adaptation. Moreover, the BCAAs are …
The Role Of Superantigens During Staphylococcus Aureus Nasal Colonization And Infection, Stacey Xu
The Role Of Superantigens During Staphylococcus Aureus Nasal Colonization And Infection, Stacey Xu
Electronic Thesis and Dissertation Repository
Superantigens (SAgs) are potent toxins produced by bacteria such as Staphylococcus aureus that function to overactivate T cells resulting in massive cytokine production and immune activation. Despite decades of research on the structure and function of these proteins, as well as their role in severe diseases such as toxic shock syndrome, the question as to why strains of S. aureus produce SAgs and the role that they play in the life cycle of these bacteria remains unanswered. The contribution of SAgs towards pathogenicity and bacterial survival in vivo were assessed using isogenic SAg deletion knockouts in conjunction with SAg-sensitive humanized …