Novel antibiotics effective against gram-positive and -negative multi-resistant bacteria with limited resistance

The authors generated a new family of peptidomimetics—cyclic heptapseudopeptides—inspired from a natural bacterial peptide. Out of the 4 peptides studied, 2 are effective against methicillin-resistant Staphylococcus aureus (MRSA) in mild and severe sepsis mouse models without exhibiting toxicity on human erythrocytes and kidney cells, zebrafish embryos, and mice. These new compounds are safe at their active doses and above, without nephrotoxicity. Efficacy was also demonstrated against Pseudomonas aeruginosa and MRSA in a mouse skin infection model. Importantly, these compounds did not result in resistance after serial passages for 2 weeks and 4 or 6 days’ exposure in mice.