Monocaprin, Monolaurin, and Monomyristin Eradicate Staphylococcus aureus Persister Cells Through Membrane Disruption

Area of Science:

• Microbiology
• Biochemistry

Background:

• Staphylococcus aureus persister cells pose a significant challenge to antimicrobial therapy due to their antibiotic tolerance.
• Chronic and recurrent infections are often linked to these resilient bacterial populations.
• The potential of monoglycerides as membrane-active antimicrobials is recognized, but their impact on persister cells requires further investigation.

Purpose of the Study:

• To evaluate the efficacy of monocaprin, monolaurin, and monomyristin against Staphylococcus aureus persister cells.
• To elucidate the mechanism of action of these monoglycerides on persister cell viability.
• To explore the role of membrane disruption in the anti-persister activity.

Main Methods:

• Assessing the anti-persister activity of three monoglycerides against S. aureus.
• Employing membrane permeability assays to investigate cellular effects.
• Utilizing fluorescence microscopy for mechanistic analysis.
• Testing the influence of Tween 80 on monoglyceride activity and membrane permeability.

Main Results:

• Monocaprin, monolaurin, and monomyristin demonstrated reduced survival of S. aureus persister cells.
• Monolaurin showed the highest anti-persister activity; monocaprin and monomyristin exhibited concentration-dependent bactericidal effects.
• Monoglycerides increased membrane permeability, leading to compromised persister cell viability.
• Tween 80 counteracted the bactericidal effects and membrane permeability increase, confirming membrane disruption as the mode of action.

Conclusions:

• The antibacterial action of monocaprin, monolaurin, and monomyristin against S. aureus is intrinsically linked to membrane damage.
• These membrane-active monoglycerides show promise as novel agents for eradicating S. aureus persister cells.
• Targeting bacterial membranes presents a viable strategy against persistent S. aureus infections.