During the development of antimicrobial peptides (AMP) as potential therapeutics, antimicrobial susceptibility testing (AST) stands as an essential part of the process in identification and optimisation of candidate AMP. Standard methods for AST, developed almost 60 years ago for testing conventional antibiotics, are not necessarily fit for purpose when it comes to determining the susceptibility of microorganisms to AMP. Without careful consideration of the parameters comprising AST there is a risk of failing to identify novel antimicrobials at a time when antimicrobial resistance (AMR) is leading the planet toward a post-antibiotic era. More physiologically/clinically relevant AST will allow better determination of the preclinical activity of drug candidates and allow the identification of lead compounds. An important consideration is the efficacy of AMP in biological matrices replicating sites of infection, e.g., blood/plasma/serum, lung bronchiolar lavage fluid/sputum, urine, biofilms, etc., as this will likely be more predictive of clinical efficacy. Additionally, specific AST for different target microorganisms may help to better predict efficacy of AMP in specific infections. In this manuscript, we describe what we believe are the key considerations for AST of AMP and hope that this information can better guide the preclinical development of AMP toward becoming a new generation of urgently needed antimicrobials.

在抗菌肽 (AMP) 作为潜在治疗药物的开发过程中，抗菌药敏感性测试 (AST) 是候选 AMP 识别和优化过程的重要组成部分。大约 60 年前开发的用于测试传统抗生素的 AST 标准方法不一定适合确定微生物对 AMP 的敏感性。当抗菌素耐药性 (AMR) 正在引领地球迈向后抗生素时代时，如果不仔细考虑 AST 组成的参数，就有可能无法识别新型抗菌药物。更多的生理/临床相关 AST 将有助于更好地确定候选药物的临床前活性，并识别先导化合物。一个重要的考虑因素是 AMP 在复制感染部位的生物基质中的功效，例如血液/血浆/血清、肺细支气管灌洗液/痰、尿液、生物膜等，因为这可能更能预测临床疗效。此外，针对不同目标微生物的特定 AST 可能有助于更好地预测 AMP 在特定感染中的功效。在这篇手稿中，我们描述了我们认为 AMP AST 的关键考虑因素，并希望这些信息能够更好地指导 AMP 的临床前开发，使其成为新一代急需的抗菌药物。