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Full-Text Articles in Life Sciences
Staphylococcus Aureus Small Colony Variants Use Heme And Staphyloferrin B For Iron Acquisition, Izabela Z. Batko
Staphylococcus Aureus Small Colony Variants Use Heme And Staphyloferrin B For Iron Acquisition, Izabela Z. Batko
Electronic Thesis and Dissertation Repository
Iron is an essential nutrient for the bacterium Staphylococcus aureus. Wild-type S. aureus utilizes various iron acquisition systems to support growth in iron deplete conditions. S. aureus small colony variants (SCVs) are associated with chronic infections, yet the mechanisms by which these variants acquire iron are unknown. Mutation of hemB, involved in heme biosynthesis, generated a stable SCV that was auxotrophic for hemin and formed small colonies on solid media. To support growth under iron deplete conditions, my data revealed that S. aureus hemB synthesizes the siderophore staphyloferrin B, but not staphyloferrin A, although both siderophores could be …
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 …
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 …