Designing an ultra-short antibacterial peptide with potent activity against Mupirocin-resistant MRSA.

Staphylococcus aureus is the pathogen responsible for the majority of human skin infections. In particular, the methicillin-resistant variety, MRSA, has become a global clinical concern. The extensive use of mupirocin, the first-line topical antibacterial drug of choice, has led to the emergence of mupirocin-resistant MRSA globally, resulting in the urgent need for a replacement. Antimicrobial peptides are deemed plausible candidates. Herein, we describe a structure-activity relationship approach in the design of an ultra-short peptide with potent anti-MRSA activity with a rapid, bactericidal mode of action. Coupled to a low cytotoxic activity, we believe our lead compound can be developed into a topical antibacterial agent to replace mupirocin as the first-line drug for treating MRSA skin infections.