This paper is about Zosurabalpin novel tethered macrocyclic peptide antibiotic that kills carbapenem-resistant Acinetobacter baumannii.In two recent studies published back-to-back in Nature, Bradley′s and Kahne′s teams reported a novel tethered macrocyclic peptide (MCP) antibiotic called zosurabalpin, which targets the LptB2FGC complex in the inner membrane to block lipopolysaccharide (LPS) transport, leading to the accumulation of this endotoxin in the cell, ultimately resulting in the death of the bacteria .Zosurabalpin not only showed excellent antibacterial activity against carbapenem-resistant Acinetobacter baumannii (CRAB) in vivo and in vitro, but is also expected to break through the resistance mechanisms of existing antibiotics, offering new prospects for clin. treatment.A.baumannii, a Gram-neg. bacterium with an outer membrane containing LPS, is resistant to penetration by a wide range of antibiotics, making it difficult to kill. It.It Is one of the common causative agents of hospital-acquired infections and results in hospital-acquired pneumonia, bloodstream infections, urinary tract infections, and soft tissue skin infections.In summary, zosurabalpin, with its distinctive mechanism of action, selective antibacterial activity, highly potent in vitro and in vivo efficacy, and favorable tolerability, exhibits notable competitive advantages in the domain of CRAB therapy.First, zosurabalpin is highly selective for CRAB and has limited activity against other Gram-neg. and Gram-pos. bacteria, helping to minimize the impact on normal flora and thus potentially reducing associated side effects.Second, due to the novel mechanism of action of zosurabalpin, CRAB currently lacks an effective defense mechanism in the face of zosurabalpin, which will provide a new option for the clin. treatment of drug-resistant strains.Consequently, it is imperative to investigate the potential of combining zosurabalpin with other antibiotics to enhance thera- peutic efficacy and impede the emergence of resistance.We can also further chem. modify MCPs to improve their stability, bioavailability, and reduce potential side effects.