A Biosurfactant-Inspired Heptapeptide with Improved Specificity to Kill MRSA.

The emergence and rapid spread of methicillin-resistant Staphylococcus aureus (MRSA) poses a serious threat to public health. New antibiotics and strategies are urgently needed to combat S. aureus associated infections. Bacaucin, a novel cyclic lipopeptide from Bacillus subtilis CAU21, is reported. Bacaucin shows broad antibacterial activity against Gram-positive bacteria, but is also hemolytic and cytotoxic. However, bacaucin-1, a bacaucin-inspired ring-opened heptapeptide, shows specific antibacterial activity against MRSA by a membrane-disruptive mechanism without detectable toxicity to mammalian cells or induction of bacterial resistance. Bacaucin-1 was efficient in preventing infections in both in vitro and in vivo models and is a valuable prototype antibiotic with high potential against S. aureus infections.