Isolation and characterization of novel antimicrobial peptide from the black soldier fly, Hermetia illucens

Maggot therapy is highly successful in cleansing infected and necrotic wounds. The main actions of fly maggots on wounds may be categorized into three modes: debridement, disinfection and bacterial death, and stimulation of tissue granulation and repair. However, the use of maggot therapy declined as antibiotics developed and surgical techniques improved. Nevertheless, new strains of pathogenic fungi and bacteria developed primarily in response to overdose usage of antibiotics and thus found commonly in hospitals and wider. In this study, we report that immunized hemolymph of Hermetia illucens with Staphylococcus aureus exhibit a potent, broad-spectrum activity against Gram negative and Gram positive bacteria including Methicillin-resistant Staphylococcus aureus (MRSA). The larvae of H. illucens were induced with Gram+ bacteria, and their hemolymph extracts were preparatively purified with C18 SPE against various acetonitrile concentrations and, subsequently, using RPC. Fractions exhibiting activity against E. coli, MRSA, and both were separately collected and pooled, and fractions exhibiting anti-MRSA activity were further purified by C18 HPLC column. The data provide evidence that this fraction possesses a novel AMP that could be developed into therapeutically useful anti-infective agents and thus, is worth further studies on its physical/structural and functional properties and, in particular, investigations on its antimicrobial mechanism(s). We will discuss this substance.