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Introduction: Small colony variants (SCVs) of Staphylococcus aureus (S. aureus) are associated with persistent infections and poor clinical outcomes. The mechanisms driving stable SCV formation remain poorly understood, particularly concerning metabolic adaptations. This study explores the in-host evolutionary dynamics of S. aureus and identifies a novel genetic determinant linked to SCV formation.
Objectives: To investigate the genetic mutations and phenotypic adaptations underlying SCV formation, with a focus on the role of a novel mutation in the sufB gene, which is critical for Fe-S cluster biosynthesis.
Methods: Sequential isolates from a patient with recurrent infections were analyzed using whole-genome sequencing, antimicrobial susceptibility testing, and functional assays. The phylogenetic relationship of the isolates was determined, and specific mutations were identified. Functional assays included aconitase and glutamate synthase activity measurements, ATP level quantification, reactive oxygen species (ROS) production, and biofilm formation assays. In vivo pathogenesis was assessed using a murine catheter infection model.
Results: A novel frameshift mutation in sufB was identified, disrupting Fe-S cluster biosynthesis and impairing the TCA cycle and electron transport chain, leading to reduced ATP and ROS production. This metabolic reprogramming promoted stable SCV formation, characterized by slow growth, enhanced tolerance to antibiotics and neutrophil-mediated killing, and persistent inflammation in vivo. Restoration of sufB reversed these phenotypes, confirming its pivotal role in SCV-associated persistence.
Conclusion: sufB is a novel genetic determinant of stable SCV formation through Fe-S cluster deficiency, driving metabolic shifts that enhance immune evasion and chronic infection. Our findings highlight antibiotic stewardship and suggest potential therapeutic strategies for managing persistent SCV-associated infections.
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http://dx.doi.org/10.1016/j.jare.2025.05.018 | DOI Listing |
J Am Chem Soc
September 2025
Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States.
Iron homeostasis is essential for the virulence of the opportunistic fungal pathogen . The cytosolic monothiol glutaredoxin GrxD was recently shown to play a critical role in iron metabolism via regulation of iron-sulfur (Fe-S) binding iron-responsive transcription factors and interaction with components of the cytosolic Fe-S cluster assembly pathway. Interestingly, the putative copper-binding metallothionein CmtA was also identified as a binding partner for GrxD; however, the metal-binding properties of both proteins and the nature of their interactions were unclear.
View Article and Find Full Text PDFBiomater Sci
September 2025
Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics Hubei Bioinformatics & Molecular Imaging Key Laboratory, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, Hubei,
Cuproptosis is a copper-dependent programmed cell death triggered by mitochondrial dysfunction, which offers significant anti-tumor potential but requires tumor-specific copper delivery to avoid systemic toxicity. Here, we developed a synergistic nanoplatform (CuO@SiO-Ce6, CSC) integrating cuproptosis induction with photodynamic therapy (PDT). A cuprous oxide (CuO) core was encapsulated in silicon dioxide and covalently linked to the photosensitizer Ce6.
View Article and Find Full Text PDFSmall
September 2025
Department of Chemical Engineering and Technology, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094, P. R. China.
Photocatalytic nitrogen reduction to ammonia (NH) under ambient conditions offers a sustainable alternative to the energy-intensive Haber-Bosch process but faces significant challenges. Inspired by biological nitrogen fixation, a thiosalicylic acid (TSA)-derived Fe-S cluster catalyst with dual active sites (FeS and FeS) is rationally designed and synthesized. Guided by the hard-soft acid-base (HSAB) theory, the Fe⁺/Fe⁺ ratio in the iron source is optimized to regulate the content of these two coordination structures in the catalysts.
View Article and Find Full Text PDFFree Radic Biol Med
August 2025
Department of School of Medicine, Nankai University, Tianjin, 300071, China; Department of Anesthesiology, Tianjin First Central Hospital, Tianjin, 300380, China. Electronic address:
Background And Aims: Myofascial pain syndrome (MPS), driven by dysfunction in myofascial trigger points (MTrPs), remains mechanistically unclear. This study aimed to explore miR-15 b's function in MTrP pathogenesis, focusing on its regulation of iron-sulfur (Fe-S) cluster synthesis and mitophagy.
Methods: A rat MTrP model was established using repetitive mechanical injury and eccentric exercise.
J Am Chem Soc
September 2025
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
The Mo nitrogenase is more efficient for N reduction than the alternative nitrogenases for reasons that are not fully understood. A set of related hypotheses center on the Mo ion facilitating electron delocalization, which could aid in substrate activation and/or provide enhanced stability during turnover, among other possibilities. To understand how the incorporation of Mo or other 'heterometals' influences the electronic structures of Fe-S clusters, we prepared and characterized an isostructural and isoelectronic series of [MFeS] clusters (M = V, Cr, Mo, W) that includes the first example of a [CrFeS] cluster.
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