A novel antimicrobial peptide Spamprin(4-23) from Scylla paramamosain exhibiting potent antimicrobial activity and protective effects against Vibrio alginolyticus.

“A novel antimicrobial peptide Spamprin(4-23) from Scylla paramamosain exhibiting potent antimicrobial activity and protective effects against Vibrio alginolyticus. Zhu X(1), Zhang W(1), Li S(1), Chen F(2), Wang KJ(3). Author information: (1)State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, Fujian, China; State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, College of Ocean & Earth Sciences, Xiamen University, Xiamen, Fujian, China. (2)State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, Fujian, China; State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, College of Ocean & Earth Sciences, Xiamen University, Xiamen, Fujian, China; Marine Biological Antimicrobial Peptide Industry Research Institute, Fujian Ocean Innovation Center, Xiamen, China. Electronic address: chenfangyi@xmu.edu.cn. (3)State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, Fujian, China; State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, College of Ocean & Earth Sciences, Xiamen University, Xiamen, Fujian, China; Marine Biological Antimicrobial Peptide Industry Research Institute, Fujian Ocean Innovation Center, Xiamen, China. Electronic address: wkjian@xmu.edu.cn. Vibrio species are ubiquitous in aquatic environments and represent significant pathogens in marine aquaculture, with Vibrio alginolyticus being a primary threat to farmed aquatic animals. The limited availability of therapeutic drugs in aquaculture, compounded by widespread antibiotic resistance, necessitates the development of new antibacterial strategies. In this study, a previously uncharacterized functional gene, designated as Spamprin, was identified in Scylla paramamosain. Its transcripts exhibited tissue-specific distribution and were markedly upregulated following LPS stimulation. Through bioinformatics analysis and prediction using antimicrobial peptide databases, a truncated peptide, Spamprin4-23 derived from Spamprin was screened. The peptide demonstrated potent antimicrobial activity against a wide range of microorganisms in vitro. Mechanistically, Spamprin4-23 significantly increased bacterial membrane permeability and induced morphological changes in target microorganisms. Importantly, it exhibited no cytotoxic effects against crab hemocytes or mammalian HEK293T cells. Although Spamprin4-23 showed no direct bactericidal activity against V. alginolyticus in vitro, it reduced bacterial burden in host tissues and conferred significant protection, leading to improved survival of V. alginolyticus-challenged mud crabs. This effect was most likely associated with the immunomodulatory activity of the peptide, as evidenced by the modulation of immune-related gene expression. Collectively, these findings suggest that Spamprin4-23 may serve as a promising immunomodulatory agent for disease control in aquaculture, offering a viable alternative to conventional antibiotic-based strategies. Copyright © 2026. Published by Elsevier Ltd. Conflict of interest statement: Declaration of Competing Interest There are no conflicts to declare.”