Preoral and Oral Digestion of Leishmania Major Parasite by Lucilia Sericata Larvae

Background: Zoonotic cutaneous leishmaniasis (ZCL) caused by Leishmania major as the cause of chronic wounds is an increasing problem in tropical and subtropical regions of the world. For many years, Lucilia sericata larvae have been considered as a complementary treatment method for chronic wounds. In previous studies, the anti-leishmanial effects of the whole body of the larvae and their excretion/secretion products have been approved, but the time of the effect and ingestion of the parasite by the larvae has not been investigated. In this study, the exposure of L. major parasite to L. sericata in the environment inside and outside the larva's body was investigated. Methods: The life cycle of L. sericata was established in insectarium. The L. major parasite was passaged until the logarithmic phase. Larvae-parasites interaction was investigated in various nutritional environments and times. For the interaction outside of the larval body, tracking of parasites and their viability was done by microscopic, MTT and Trypan blue examinations. Parasites were tracked inside the larva's body with microscopic and molecular methods. Results: Due to the antimicrobial properties of larvae, the parasites were deactivated ۴ hours after interacting with the larvae, and after ۶ hours in the larval nutritional environment, they were lysed. The absence and inactivity of the parasite in the selective interaction environment were confirmed by the indicated methods. The number of alive cells in the treatment group showed a significant increase compared to the control. The genomic DNA of parasites and not alive parasites was detected in the body of L. sericata larvae through molecular methods. Conclusion: For the first time, this study displayed that the interaction of L. sericata with L. major for use in leishmaniasis treatment should last at least ۶ hours so that the parasites are completely destroyed. In addition, intra- and extra-oral digestion of L. sericata larvae kills L. major. It was also shown that increasing the microbiota in the interaction environment could help suppress the Leishmania parasite population. Considering the removal of parasites by L. sericata larvae, the potential of therapeutic larvae could be used in the treatment of ZCL.

کلیدواژه ها:

Zoonotic Cutaneous Leishmaniasis ، maggot therapy ، antimicrobial peptides ، microbiota