Isolation and the antibacterial activity against MRSA strains of low molecular weight antibacterial substances from maggots of the black soldier fly, Hermetia illucens

Maggots have become highly successful in the treatment of non-healing wounds and multidrug-resistant pathogen infections. The objective of the present study was to induce and extract antibacterial substances from larvae of the black soldier fly, Hermetia illucens. To induce immune responses, we have septically injured the larvae with a contaminated needle, and subsequently, isolated the antibacterial substances from the larval extracts, which were shown to be highly stable as a freeze-dried preparation. In addition, we have examined the antibacterial effects of the low molecular weight (<3 kDa) antibacterial factors within the larval extracts on the growth of a broad range of bacteria, including the Gram-positive Staphylococcus aureus, methicillin resistant Staphylococcus aureus (MRSA), and the Gram-negative Pseudomonas aeruginosa. These investigations revealed that larval extracts possessed a broad-spectrum of antibacterial activity, demonstrating that secretions of H. illucens larvae prove useful in the fight against MRSA and can potentially be a source of novel antibiotic-like compounds for infection control.