The influence of maggot excretions on PAO1 biofilm formation on different biomaterials.

Biofilm formation in wounds and on biomaterials is increasingly recognized as a problem. It therefore is important to focus on new strategies for eradicating severe biofilm-associated infections. The beneficial effects of maggots (Lucilia sericata) in wounds have been known for centuries. We hypothesized sterile maggot excretions and secretions (ES) could prevent, inhibit, and break down biofilms of Pseudomonas aeruginosa (PAO1) on different biomaterials. Therefore, we investigated biofilm formation on polyethylene, titanium, and stainless steel. Furthermore, we compared the biofilm reduction capacity of Instar-1 and Instar-3 maggot ES and tested the temperature tolerance of ES. After biofilms formed in M63 nutrient medium on comb-forming models of the biomaterials, ES solutions in phosphate-buffered saline or M63 were added in different concentrations. PAO1 biofilms adhered tightly to polyethylene and titanium but weakly to stainless steel. Maggot ES prevent and inhibit PAO1 biofilm formation and even break down existing biofilms. ES still had considerable biofilm reduction properties after storage at room temperature for 1 month. ES from Instar-3 maggots were more effective than ES from Instar-1 maggots. These results may be relevant to patient care as biofilms complicate the treatment of infections associated with orthopaedic implants.