Publications by authors named "Mara J Campbell"
Article Synopsis
- - The study shows that mutating the staphylococcal accessory regulator A (sarA) in the USA300 strain LAC significantly reduces virulence in a mouse model for osteomyelitis more effectively than altering the accessory gene regulator (agr), regardless of the status of another gene (likely referring to a specific gene related to virulence).
- - The researchers found that protease production decreased in the sarA mutant, whereas it increased in the agr and another mutant; these changes affected biofilm formation and cytotoxicity of conditioned medium (CM) against bone cells.
- - The research concluded that increased production of extracellular proteases limits the effectiveness of key virulence factors, such as toxins, thereby reducing the overall virulence
Staphylococcus aureus osteomyelitis leads to extensive bone destruction. Osteoclasts are bone resorbing cells that are often increased in bone infected with S. aureus.
View Article and Find Full Text PDFWe previously demonstrated that mutation of in limits biofilm formation, cytotoxicity for osteoblasts and osteoclasts, and virulence in osteomyelitis, and that all of these phenotypes can be attributed to the increased production of extracellular proteases. Here we extend these studies to assess the individual importance of these proteases alone and in combination with each other using the methicillin-resistant USA300 strain LAC, the methicillin-susceptible USA200 strain UAMS-1, and isogenic mutants that were also unable to produce aureolysin (Aur), staphopain A (ScpA), staphylococcal serine protease A (subsp.), staphopain B (SspB), and the staphylococcal serine protease-like proteins A-F (SplA-F).
View Article and Find Full Text PDFBecause biofilm formation is such a problematic feature of infections, much effort has been put into identifying biofilm inhibitors. However, the results observed with these compounds are often reported in isolation, and the methods used to assess biofilm formation vary between labs, making it impossible to assess relative efficacy and prioritize among these putative inhibitors for further study. The studies we report address this issue by directly comparing putative biofilm inhibitors using a consistent assay.
View Article and Find Full Text PDFArticle Synopsis
- Researchers found that several regulatory proteins (MgrA, SarA, SarR, SarS, SarZ, and Rot) interact with promoters of protease genes in certain bacterial strains.
- * They aimed to understand how these proteins affect bacterial virulence by testing mutants in mice, revealing that mutations in SarA and another protein significantly reduced the virulence of one strain but not another.
- * The study concluded that SarA plays a critical role in controlling protease production and that assessing different clinical isolates is crucial for understanding the impact of these mutations on bacterial virulence.
We previously reported the development of an osteogenic bone filler scaffold consisting of degradable polyurethane, hydroxyapatite, and decellularized bovine bone particles. The current study was aimed at evaluating the use of this scaffold as a means of local antibiotic delivery to prevent infection in a bone defect contaminated with Staphylococcus aureus. We evaluated two scaffold formulations with the same component ratios but differing overall porosity and surface area.
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