The therapeutic effects of larval excretion/secretion of Lucilia sericata on Leishmania major under in vitro and in vivo conditions

Background Leishmaniasis is a neglected infectious disease caused by a kinetoplastid protozoan. The disease generally manifests as characteristic skin lesions. Due to the lack of definitive treatment and drugs without side effects, many studies have focused on natural compounds as promising drugs for its treatment. This study aimed to evaluate the effects of larval excretion/secretion products (ES) of Lucilia sericata in crude and fractionated forms on Leishmania parasites under both in vitro and in vivo conditions. Methods In vitro experiments involved evaluation of ES products on both promastigotes and amastigotes inside infected macrophages, whereas in vivo experiments included comparative treatments of Leishmanial lesions of mice using Eucerin-formulated ES products and glucantime. Results The IC50 values were 38.7 µg/ml, 47.6 µg/ml, 63.3 µg/ml, and 29.1 µg/ml for crude ES, over 10 kDa ES-fraction, under 10 kDa ES-fraction, and glucantime respectively. Significant differences were observed between viability percentages of promastigotes treated with crude ES and its fractions compared to negative control (p < 0.0001). Crude ES was more effective on amastigote than other two ES fractions at 300 µg/ml concentration. Macroscopic measurement of lesion sizes revealed that the reduction of lesion size in mice treated with crude ES followed quicker cascades of healing than in those treated with glucantime and fractionated ES. Conclusion The present study showed that larval ES of Lucilia sericata in both crude and fractionated forms are effective on both intracellular and extracellular forms of L. major. It also provided evidence that the larval ES exerts both topical and systemic therapeutic effects on leishmanial lesions of the model animal.

Evaluation of Excreta/Secreta of Lucilia sericata Larvae as a New Antibacterial Candidate for Treatment of MRSA Ocular Infection

Staphylococcus aureus is the most serious cause of bacterial keratitis in most populations. Due to the resistance of this bacteria to methicillin (MRSA), the novel antimicrobial component is required for novel treatments for keratitis. Excretions/secretions (ES) from larvae of Lucilia sericata (maggot) have antibacterial activity against a number of bacteria. Around 500 larvae were washed with 1 mL of sterile water every hour for ES development. Bactericidal activity of ES was examined by time killing assay. MRSA strain was injected intrastromal into rabbit corneas. The rabbits have been split into three categories, including artificial tear, gentamicin, and maggot ES. Following, the eyes were clinically examined by a slit lamp. This evaluation included the conjunctiva, iris, and cornea. Lastly, the cornea of rabbits was collected for bacterial colony counts. After statistical analysis by ANOVA, it was found that gentamicin and ES, significantly reduced ocular infections in rabbits. Comparisons of corneal opacity scores with Mann–Whitney U-test showed a decreasing trend of therapeutic effects as shown below: gentamicin˃ES˃control. Gentamicin and ES significantly decrease CFU (number of colony-forming units) compared with the control. The mean bacterial count (log CFU/mL) from corneal culture for ES, gentamicin, and untreated groups were 6.04, 5.0, and 8.9, respectively (P≤0.05). In conclusion, the extraction of maggot larvae is useful in treating keratitis mediated by MRSA.

Improving Maggot Therapy: Mass Rearing And Molecular Identification of Lucilia Sericata (Meigen, 1826) Larvae In Maggotarium, School of Health, Shiraz

Background: Lucilia sericata as a member of the family Caliphoridae has a complete metamorphosis. They feed on on necrotic and livingtissues as necrophage species. Sterile larvae of this species has been utilized to heal wounds for decades. The aim of this study were to establish the breeding and identifying of the L.sericata species based on morphological and molecular techniques. Freshly harvested grown under standard conditions in the maggotarium of Health School , Shiraz of. They were screened using conventional morphology, then Primarily, different parameters related to larvae were measured morphologically. Subsequently, DNA was extracted and molecular marker of cytochrome C oxidase (co1) was amplified using PCR assay and sequence data were used for molecular and phylogenetic analysis. Result: In this study, 50 samples which grown collected from maggotarium were identified as L. sericata using morphological and molecular methods. This species was placed in a separate clade of the phylogenetic tree based on COI nucleotide sequences of different species and has a phylogenetic similarity to Lucilia purpurascens species of flies. Conclusion: Larval therapy especially by Lucilia sericata is a promising strategy in wound healing. Due to the importance of larval species in this technique, having an accurate knowledge of aplicable species leads to a proper larval therapy. Increasing in resistance of wounds to antibiotics has led to the use of maggot therapy in the past. Larval therapy is a low-cost, non-surgical way to remove dead tissue (predecessors and necrosis) in chronic wounds and prevents excessive soft tissue damage and infection from reaching the underlying tissues and bones (osteomyelitis). Maggot therapy is a promising way to prevent amputation, especially in people with diabetes.