Dermal infections requiring treatment are usually treated
with
conventional antibiotics, but the rise of bacterial resistance to
first-line antibiotics warrants alternative therapeutics. Here, we
report that a backbone-cyclized antimicrobial peptide, CD4-PP, designed
from the human host defense peptide LL-37, has strong direct antibacterial
effects on antibiotic sensitive as well as resistant-type strains
and clinical isolates of common skin pathogens in the low (<2)
μM range. In addition, it influences innate immunity in keratinocytes,
and treatment with CD4-PP is able to clear bacterial infections in
infected keratinocytes. Additionally, CD4-PP treatment significantly
reduces the wound area in a lawn of keratinocytes infected with MRSA.
In conclusion, CD4-PP has the potential to serve as a future drug
treating wounds infected with antibiotic-resistant bacteria.