Escherichia coli Challenging Modulate the Humoral Immune Response of Lucilia cuprina(Diptera: Calliphoridae)

Abstract

Antimicrobial compounds are recently emerging as anti-infectious agents that can be applied topically or systemically to speed up wound healing process. Maggot debridement therapy has become more prevalent in the treatment of chronic wound. This study focuses on studying the activity of commonly used natural compounds, which can be extracted from the whole and fat bodies of Lucilia cuprina. The current report was designed to investigate the effect of injecting bacterial suspension of Escherichia coli during the development of Lucilia cuprina at different time points. Measurements involved the assay of (a) total protease activities, (b) semi-quantitative RT-PCR for selected antimicrobial peptides genes expressions and (c) antioxidant capacity measurement as part of normal responding elements to humoral innate immunity (represented by lipid peroxide (Malondialdehyde) and glutathione reduced levels). Total lipid content in immature stages was also assessed. The results revealed an increase in total proteases activities and antioxidant capacities (low Malondialdehyde and high reduced glutathione levels) during the 3rd instar larvae and pupal phases after bacterial challenge. Detection of an increased mRNA expression levels in the fat body for lysozyme, cecropin, and attacin genes after bacterial-infection indicate high antibacterial activity in early pupae at 1h after infection. In conclusion, our findings may draw attention proposing that naturally extracted compounds from the whole and fat body of Lucilia cuprina, which are rich in proteolytic enzymes, as novel larval-based therapy in parallel to the traditional known ones. Further studies are required to illustrate the exact components of the extracts.