Lau, Q.Y., Choo, X.Y., Lim, Z.X. et al. Int J Pept Res Ther (2015) 21: 21. doi:10.1007/s10989-014-9440-x
The rapid emergence of drug-resistant bacteria and the lack of new antibiotics entering the market is a major worldwide concern. Antimicrobial peptides are deemed plausible drug candidates as they specifically target and disrupt microbial cell membranes, causing death by cell lysis. However, their instability towards plasma proteases and perceived high manufacturing cost limit their potential for further drug development. A plausible solution is to identify and develop very short linear peptides as topical agents for treating skin and soft tissue infections. A literature survey yielded 30 ultra-short antimicrobial peptides up to 9 residues in length with antimicrobial activities. They were commercially synthesized and a head-to-head antimicrobial activity comparison was conducted on common skin pathogens including meticillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Candida albicans. The topical broad-spectrum antibiotic Gentamicin and antifungal Nystatin were included as controls. Experimental results revealed only 2 peptides with potent broad-spectrum activities; octapeptide IRIRIRIR-NH2 and nonapeptide Ac-KWRRWVRWI-NH2 exhibited MICs of 6.25 uM against all test microbes. Both peptides have been reported to be non-cytotoxic to human cells, suggesting that they could potentially be further developed as topical antimicrobial agents.