College of Fisheries, Tianjin Agricultural University, 22 Jinjing Road, 300384, Tianjin, China.
College of Fisheries, Tianjin Agricultural University, 22 Jinjing Road, 300384, Tianjin, China; Tianjin Key Laboratory of Aqua-ecology and Aquaculture, 22 Jinjing Road, 300384, Tianjin, China.
Microb Pathog. 2024 Nov;196:106879. doi: 10.1016/j.micpath.2024.106879. Epub 2024 Aug 30.
Epinecidin-1 (Epi-1) is an antimicrobial peptide originated from fish with various pharmacological activities but carries the risk of acquiring resistance with long-term use. In the present study, we use L-lactic acid to enhance the antibacterial activity of synthesized Epi-1 against the aquaculture and food pathogen Aeromonas hydrophila. The results showed that 5.5 mmol/L lactic acid increased the inhibitory and bactericidal activity of 25 μmol/L Epi-1 against two strains of A. hydrophila. The laser confocal images proved that lactic acid pre-treatment improved the attachment efficiency of Epi-1 in A.hydrophila cells. In addition, lactic acid enhanced the damaging effect of Epi-1 on the cell membrane of A. hydrophila, evidenced by releasing more nucleic acids, proteins, and transmembrane pH ingredients decrease and electromotive force dissipation. SEM images showed that compared with the single Epi-1 treatment, the co-treatment of Epi-1 and lactic acid caused more outer membrane vesicles (OMVs) and more severe cell deformation. These findings proved that lactic acid could enhance the efficiency of Epi-1 against A. hydrophila and shed light on new aspects to avoid resistance of pathogens against Epi-1.
鱼源抗菌肽 Epinecidin-1（Epi-1）具有多种药理活性，但长期使用可能会产生耐药性。本研究采用 L-乳酸来增强合成的 Epi-1 对水产养殖和食品病原菌嗜水气单胞菌的抗菌活性。结果表明，5.5mmol/L 乳酸可提高 25μmol/L Epi-1 对两种嗜水气单胞菌的抑菌和杀菌活性。激光共聚焦图像证实，乳酸预处理可提高 Epi-1 在 A.hydrophila 细胞上的附着效率。此外，乳酸增强了 Epi-1 对嗜水气单胞菌细胞膜的损伤作用，表现为释放更多的核酸、蛋白质和跨膜 pH 成分下降以及电动力耗散。SEM 图像显示，与单独使用 Epi-1 相比，Epi-1 和乳酸的联合处理导致更多的外膜囊泡（OMVs）和更严重的细胞变形。这些发现证明了乳酸可以提高 Epi-1 对嗜水气单胞菌的作用效率，并为避免 Epi-1 产生抗药性提供了新的思路。
