Sterilization of immature blowflies (Calliphoridae) for use in larval therapy

Abstract

The larval therapy involves the intentional application of sterilized and alive dipterans larvae on nonhealing wounds with the purpose of cleaning out the necrotic tissue to facilitate the healing process. This study aimed to evaluate the sterilization process and survival of Chrysomya megacephala (Fabricius), Chrysomya putoria (Wiedemann) and Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae) larvae, after treatment with sodium hypochlorite (NaClO). The experimental groups for each species were: control group (CG), in which it was used water; 0.5% sodium hypochlorite group (0.5% SHG); and 1% SHG. For testing the time for each treatment, the eggs were washed for one or three minutes in the described solution. After, aliquots from the "rinsing water" were inoculated in Plate Count Agar (PCA) and blood agar (BA), with incubation at 37ºC and readings performed after 24 and 48 hours for both. For all species, there were no bacterial growth on PCA and BA regarding to both treatments, 0.5% SHG and 1.0% SHG. The survival rate and intervals of immersion were similar among the CG and the different concentrations of NaClO for all species. In conclusion, sterilization of blowflies' eggs made by NaClO is an efficient method to obtain the sterilized larvae for larval therapy.