Disarming the Pathogenicity of Methicillin-Resistant Staphylococcus aureus via Osmundacetone-Mediated Inhibition of...

Area of Science:

• Microbiology
• Pharmacology
• Natural Products Chemistry

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant global health challenge due to multidrug resistance.
• The emergence of antibiotic resistance necessitates the development of novel therapeutic strategies.
• Sortase A (SrtA) is a critical virulence factor in S. aureus, essential for bacterial adhesion and infection, making it an attractive drug target.

Purpose of the Study:

• To investigate the potential of osmundacetone (OSC), a natural compound, as an inhibitor of Sortase A (SrtA).
• To evaluate the efficacy of OSC against MRSA in vitro and in vivo.

Main Methods:

• Fluorescence resonance energy transfer (FRET) assays were used to determine SrtA inhibitory activity.
• In vitro assays assessed OSC's impact on bacterial adhesion, invasion, and biofilm formation.
• Molecular docking and fluorescence quenching identified the OSC binding site on SrtA.
• In vivo efficacy was evaluated in mouse and Galleria mellonella infection models.

Main Results:

• Osmundacetone (OSC) demonstrated significant inhibition of SrtA with an IC50 of 1.29 μg/mL.
• OSC effectively reduced MRSA adhesion, invasion, and biofilm formation in vitro.
• In vivo studies showed that OSC improved survival rates and reduced bacterial load in infected mice and G. mellonella.

Conclusions:

• Osmundacetone (OSC) is a potent SrtA inhibitor with broad anti-MRSA activity.
• OSC demonstrates therapeutic potential for treating MRSA infections.
• Natural compounds like OSC offer a promising avenue for developing new anti-MRSA therapies.