A copper-dependent compound restores ampicillin sensitivity in multidrug-resistant Staphylococcus aureus

Area of Science:

• Microbiology
• Infectious Diseases
• Pharmacology

Background:

• Multi-drug resistant Staphylococcus aureus (MRSA) poses a significant global healthcare challenge.
• Drug-resistant S. aureus is increasingly implicated in community-acquired infections.
• Copper-dependent inhibitors (CDIs) are a novel class of antibiotics active in the presence of copper ions.

Purpose of the Study:

• To evaluate the efficacy of a second-generation CDI, APT-6K, against MRSA.
• To investigate APT-6K's ability to synergize with ampicillin and reverse existing drug resistance.
• To assess the safety and therapeutic index of APT-6K in eukaryotic cells.

Main Methods:

• Testing bactericidal activity of APT-6K against MRSA strains.
• Evaluating synergistic effects of APT-6K with ampicillin at sub-bactericidal concentrations.
• Assessing cytotoxicity and mitochondrial activity in eukaryotic cells.

Main Results:

• APT-6K demonstrated potent bactericidal activity against MRSA at nanomolar concentrations.
• APT-6K synergized with ampicillin to reverse drug resistance in multiple MRSA strains.
• APT-6K exhibited a favorable therapeutic index (TI > 30) and did not impact mitochondrial activity.

Conclusions:

• CDIs activated by transition metal ions represent a promising antibiotic class.
• APT-6K is effective against MRSA and can reverse existing antibiotic resistance.
• APT-6K offers a potential new strategy for combating MRSA infections with a favorable safety profile.