Exploring the Antimicrobial Potential of Peptide- Extracts From Black Soldier Fly Larvae and Desert Locust Nymphs

Abstract

The ability of black soldier fly (Hermatia illucens Linnaeus Diptera: Stratiomyidae) larvae and desert locust (Schistocerca gregaria) nymphs to produce antimicrobial peptides makes them ideal candidates for the discovery of novel antimicrobials. Extraction of antimicrobial peptides from various insects have been carried out but research around these two insects is scarce. This study aimed to extract these peptides from non-immune-induced and immune-induced black soldier fly larvae and desert locust nymphs using acidified solvent. Their antimicrobial activity was tested against 10 clinical strains (nine bacteria and a yeast) using agar diffusion and 96-well plate micro-dilution assays. Promisingly, 100% of all the tested extracts from black soldier fly larvae exhibited potent antimicrobial activity against the antimicrobial-resistant microorganism, Pseudomonas aeruginosa, while 81.3% of all the tested extracts were active against the tetracycline-resistant Streptococcus agalactiae. Similarly, all tested extracts from desert locust nymphs demonstrated potent antimicrobial activity against the antimicrobial-resistant microorganisms: Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumonia, and tetracycline-resistant Streptococcus agalactiae. However, all the extracts from both desert locust nymphs and black soldier fly larvae did not show any antimicrobial effect on the yeast, Candida albicans. Additionally, the antimicrobial activity of the extracts increased in the following order with respect to the extracting solvents: butanol, isopropanol, ethanol, and methanol. In a holistic view, these findings offer valuable insights into the potential of black soldier fly larvae and desert locust nymphs as a promising source of novel antimicrobial agents, further underscoring their importance in addressing antimicrobial resistance menace.