Research Unit of Analysis and Process Applied on The Environment- APAE (UR17ES32) Higher Institute of Applied Sciences and Technology of Mahdia, University of Monastir, Monastir 5019, Tunisia.
Department of Cell Biology and Histology, Faculty of Biology, University of Murcia, Immunobiology for Aquaculture Group, Murcia 30100, Spain.
J Appl Microbiol. 2024 Sep 2;135(9). doi: 10.1093/jambio/lxae222.
Dermaseptins are one of the main families of antimicrobial peptides (AMPs) derived from the skin secretions of Hylidae frogs. Among them, dermaseptin S4 (DS4) is characterized by its broad-spectrum of activity against bacteria, protozoa, and fungi. In this study, the physicochemical properties of the native peptide DS4 (1-28) and two derivatives [DS4 (1-28)a and DS4 (1-26)a] isolated from the skin of the frog Phyllomedusa sauvagii were investigated and their antimicrobial properties against two marine pathogenic bacteria (Vibrio harveyi and Vibrio anguillarum) were examined.
The results indicate that the peptide DS4 (1-26)a has high-antibacterial activity against the tested strains and low-hemolytic activity (<30% lysis at the highest tested concentration of 100 µg/mL) compared to the other two peptides tested. In addition, all three peptides affect the membrane and cell wall integrity of both pathogenic bacteria, causing leakage of cell contents, with DS4 (1-26)a having the most severe impact. These skills were corroborated by transmission electron microscopy and by the variation of cations in their binding sites due to the effects caused by the AMPs.
These results suggest that DS4 and its derivatives, in particular the truncated and amidated peptide DS4 (1-26)a could be effective in the treatment of infections caused by these marine pathogenic bacteria. Future studies are required to validate the use of DS4 in vivo for the prevention of bacterial diseases in fish.
真皮抗菌肽（dermaseptins）是一类主要的抗菌肽（AMPs），来源于雨蛙科青蛙的皮肤分泌物。其中，真皮抗菌肽 S4（DS4）的特点是对细菌、原生动物和真菌具有广谱活性。在这项研究中，研究了从青蛙 Phyllomedusa sauvagii 皮肤中分离得到的天然肽 DS4（1-28）和两种衍生物[DS4（1-28）a 和 DS4（1-26）a]的理化性质，并研究了它们对两种海洋致病性细菌（哈维弧菌和鳗弧菌）的抗菌特性。
结果表明，与其他两种测试肽相比，肽 DS4（1-26）a 对测试菌株具有高抗菌活性，且溶血活性低（在最高测试浓度 100μg/mL 时<30%溶血）。此外，所有三种肽都影响两种致病性细菌的膜和细胞壁完整性，导致细胞内容物泄漏，其中 DS4（1-26）a 的影响最为严重。这些结果得到了透射电子显微镜和 AMPs 引起的结合部位阳离子变化的证实。
这些结果表明，DS4 及其衍生物，特别是截短和酰胺化的肽 DS4（1-26）a，可能对治疗这些海洋致病性细菌引起的感染有效。需要进一步的研究来验证 DS4 在预防鱼类细菌性疾病中的体内应用。
