A potent enzybiotic against methicillin-resistant Staphylococcus aureus

Area of Science:

• Microbiology
• Biochemistry
• Drug Discovery

Background:

• Staphylococcus aureus is a significant cause of human and animal infections.
• Multidrug-resistant (MDR) strains, including MRSA, pose a growing therapeutic challenge.
• Bacteriophage-derived endolysins are emerging as potent antibacterials targeting conserved bacterial structures.

Purpose of the Study:

• To characterize the physical, chemical, and antibacterial properties of LysMR-5.
• To evaluate LysMR-5 as a potential therapeutic agent against MDR Staphylococcus aureus.
• To assess the lytic efficacy of LysMR-5 against clinical isolates.

Main Methods:

• Cloning, expression, and purification of LysMR-5.
• In silico analysis of protein domains.
• Biochemical characterization, including optimal activity conditions and ion effects.
• Circular dichroism for thermal stability assessment.
• Antibacterial assays against various staphylococcal strains.

Main Results:

• LysMR-5 possesses two active catalytic domains and a cell wall-binding domain.
• Optimal activity observed at 37°C, pH 7.0, and high salt concentrations (≥300 mM NaCl).
• LysMR-5 exhibits potent bactericidal activity against diverse staphylococcal isolates, including MRSA.
• High lytic efficacy demonstrated at low concentrations (15 µg/ml) within 30 minutes.

Conclusions:

• LysMR-5 is a thermostable endolysin with significant antibacterial activity.
• Its rapid and potent bactericidal action makes it a promising candidate for combating MDR S. aureus infections.
• LysMR-5 represents a viable alternative or adjunct to current antibiotic therapies.