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Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus MRSA
Published on: February 9, 2011
Isovitexin Protects Mice from Methicillin-Resistant Staphylococcus aureus-Induced Pneumonia by Targeting Sortase A
Lili Tian1, Xinliang Wu2, Hangqian Yu3
1Institute of Animal Husbandry and Veterinary Medicine, Jinzhou Medical University, Jinzhou 121001, P.R. China.
Abstract:
The rise of methicillin-resistant Staphylococcus aureus (MRSA) has resulted in significant morbidity and mortality, and clinical treatment of MRSA infections has become extremely difficult. Sortase A (SrtA), a virulence determinant that anchors numerous virulence-related proteins to the cell wall, is a prime druggable target against S. aureus infection due to its crucial role in the pathogenicity of S. aureus. Here, we demonstrate that isovitexin, an active ingredient derived from a variety of traditional Chinese medicines, can reversibly inhibit SrtA activity in vitro with a low dose (IC50=24.72 μg/ml). Fluorescence quenching and molecular simulations proved the interaction between isovitexin and SrtA. Subsequent point mutation experiments further confirmed that the critical amino acid positions for SrtA binding to isovitexin were Ala-92, Ile-182, and Trp-197. In addition, isovitexin treatment dramatically reduced S. aureus invasion of A549 cells. This study shows that treatment with isovitexin could alleviate pathological injury and prolong the life span of mice in an S. aureus pneumonia model. According to our research, isovitexin represents a promising lead molecule for the creation of anti-S. aureus medicines or adjuncts.
Insights
Isovitexin, a natural compound, effectively inhibits Sortase A (SrtA) in Staphylococcus aureus. This discovery offers a promising new strategy for developing treatments against difficult-to-treat MRSA infections.
Area of Science:
- Microbiology
- Pharmacology
- Natural Products Chemistry
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant global health threat due to high morbidity, mortality, and treatment challenges.
- Sortase A (SrtA) is a critical enzyme in S. aureus pathogenicity, anchoring virulence factors to the cell wall, making it a key therapeutic target.
Purpose of the Study:
- To investigate the inhibitory potential of isovitexin, a compound from traditional Chinese medicine, against S. aureus Sortase A (SrtA).
- To elucidate the mechanism of interaction between isovitexin and SrtA and evaluate its therapeutic efficacy in vitro and in vivo.
Main Methods:
- In vitro enzyme inhibition assays to determine isovitexin's effect on SrtA activity.
- Fluorescence quenching and molecular simulations to study isovitexin-SrtA interactions.
- Point mutation experiments to identify key binding sites.
- Cell invasion assays and a mouse model of S. aureus pneumonia to assess therapeutic effects.
Main Results:
- Isovitexin demonstrated reversible inhibition of SrtA in vitro with a low IC50 value (24.72 μg/ml).
- Fluorescence quenching and molecular simulations confirmed direct interaction between isovitexin and SrtA, with binding sites identified at Ala-92, Ile-182, and Trp-197.
- Isovitexin treatment significantly reduced S. aureus invasion of A549 cells and alleviated pathological injury while prolonging survival in a mouse pneumonia model.
Conclusions:
- Isovitexin is a potent reversible inhibitor of S. aureus Sortase A.
- Isovitexin exhibits therapeutic potential by reducing bacterial invasion and improving outcomes in S. aureus infection models.
- Isovitexin represents a promising lead compound for developing novel anti-S. aureus therapeutics or adjunct treatments.
