Removal of infected
wounds using maggots has been known for centuries. Early research has shown that the maggot exosecretion, whole body, and fecal
waste products of Calliphoridae and Sarcophagidae species contain a variety of alkaline
peptides capable of inhibiting bacterial growth. Since the wide application of
antibiotics such as
penicillin, a number of
bacterial infections have become insensitive to
antibiotic treatment. In many of these instances,
maggot therapy has been successfully applied for the treatment of chronic
wounds. To identify and compare the expression patterns of anti-microbial
peptides (AMPs) from some dipteran species, transcriptome analyses were conducted for the maggots of 11 Calliphoridae and Sarcophagidae species. Species of the subfamily Calliphorinae showed relatively higher expression levels of AMPs and anti-microbial
proteins compared with those of Luciliinae and Sarcophagidae species. Furthermore, among all of the dipteran species examined, Lucilia illustris exhibited the highest transcription levels of AMPs.
Cecropin A2 and
defensin, whose expression levels were the highest among the anti-microbial
peptides, were synthesized to test their biological activity. The synthesized
peptides showed anti-microbial activities without hemolytic activities. In particular,
cecropin A2 of L. illustris exhibited the highest anti-microbial activity against all of the bacteria and fungi examined, thereby possessing the potential to be developed as a new alternative to
antibiotics. This comparative transcriptomic study may provide new insights into anti-microbial compositions of some dipteran species.