Hepcidin contributes to largemouth bass ( Micropterus salmoides ) against bacterial infections

The increasing emergence and dissemination of bacterial pathogens in largemouth bass culture accelerate the desire for new treatment measures. Antimicrobial peptides as the host ' s antimicrobial source dominate the preferred molecules for discovering antibacterial agents. Here, the potential of Hepcidin-1 from largemouth bass ( Micropterus salmoides ) (MsHep-1) against bacterial infection is demonstrated. MsHep-1 not only improved the survival rate in infection experiments involving Nocardia seriolae (12 %) and Aeromonas hydrophila (18 %) but also coped with iron overload conditions in vivo . Moreover, the antibacterial activity of MsHep-1 in vitro was identified against both gram -negative and gram -positive bacteria. Mechanistic studies show MsHep-1 leads to bacterial death by changing the bacterial membrane potential and disrupting the bacterial membrane structure. These findings demonstrate that MsHep-1 may play an important role in the host response to bacterial infection. It provides promising strategies in the application of immunosuppression prevention and control in fish. AMPs may be a promising and available reservoir for treating the current bacterial diseases.