Antibacterial Potential of a De-Novo Designed Peptide Against Bacterial Fish Pathogens

Abstract

Antimicrobial peptides (AMPs) are regarded as an alternative to traditional antibiotics for fighting antimicrobial resistance in aquaculture. In this study, we aimed to design and evaluate a novel, short, and compositionally simple peptide RH12 with potent activity against various bacterial pathogens in aquaculture. RH12 is amphipathic in nature with a net charge of +4.3. Molecular docking results showed that RH12 has a strong binding affinity towards the virulence protein of Aeromonas sobria, aerolysin. The peptide was synthesized using Fmoc-chemistry, and its antimicrobial efficacy was investigated against A. sobria, A. salmonicida, A. hydrophila, Edwardsiella tarda, Vibrio parahaemolyticus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, and methicillin-resistant S. aureus. The RH12 demonstrated good antibacterial activity against the tested bacteria, as shown by the MIC and MBC values that varied from 0.98 to 500 µM, and 8 to 600 µM, respectively. The peptide was resistant to high temperatures and continued to exhibit its antimicrobial properties in the presence of serum and salt, indicating its stability. The peptide also demonstrated minimal hemolysis towards fish RBCs even at higher concentrations. These findings suggest that the designed synthetic AMP may be a promising candidate for combating microbial infections in aquaculture.