Antimicrobial effects of novel Hermetia illucens peptides

Abstract

Abstract Antimicrobial resistance represents a significant global health challenge, implicated in nearly 5 million deaths per year. This study investigates the antimicrobial properties of selected peptides derived from the Black Soldier Fly (BSF), identified in silico . Ten synthesized peptides were evaluated in vitro against Gram-positive bacteria ( Staphylococcus aureus , Bacillus cereus ), Gram-negative bacteria ( Escherichia coli , Pseudomonas aeruginosa ), and fungi ( Aspergillus fumigatus , Candida albicans ). Cytotoxicity was assessed using human lung fibroblasts and red blood cells. Among the peptides, Hill_BB_C7176 demonstrated broad-spectrum antibacterial activity, no cytotoxicity and low hemolytic activity (IC₅₀: 31.6 - >32 µM). The peptide displayed rapid bactericidal activity achieving complete eradication at 8× its minimal inhibitory concentration. Propidium iodide uptake increased in a concentration dependent manner, indicating membrane permeabilization contributing to antibacterial activity. In addition, Hill_BB_C7176 exhibited strong binding affinity to lipopolysaccharide (lipid A). In vivo , Hill_BB_C7176 improved survival of Galleria mellonella larvae infected with S. aureus and E. coli , showing similar survival outcomes to reference antibiotics under the experimental conditions tested. These findings highlight the antibacterial potential of BSF-derived antimicrobial peptides, particularly Hill_BB_C7176, supporting the further research on the antibacterial activity of BSF antimicrobial peptides.