Abstract
Maggot therapy as an ancient method is succesfully used for treatment of acute and chronic wound infections in traumatology and orthopaedics. In this study, for the first time, the influence of sterile maggot excretions of Lucilia sericata on Pseudomonas aeruginosa (PAO1) biofilm formation on three common used orthopaedic materials was investigated.
Sterile maggot excretions were collected according to a standardized method and the protein concentration was measured. The influence of the excretions on PAO1-biofilm formation was tested on comb-like devices, especially designed for these experiments, made from polyethylene, titanium and stainless steel. These combs were made to fit into a flat-bottom 96-wells microtiter plate. In the wells a suspension of PAO1-bacteria, nutrient medium and maggot excretions were pipetted. In the control wells, no excretions were added. Combs were placed in the wells and incubated for 24 hours at 37°C. The formed biofilms were stained in crystal violet and eluted with ethanol. The Optical Density (OD 595 nm) was read to quantify biofilm formation. The experiments were conducted with excretions from young maggots (Instar-1 maggots) and full grown maggots (Instar-3 maggots). All experiments were done in quadruplicate.
The following can be concluded: PAO1-biofilm formation is the strongest on polyethylene and the weakest on stainless steel. Sterile maggot excretions are effective at preventing initial biofilm formation (p≤0.013) as well as preventing additional accumulation after its initiation (p≤0.038). The excretions even cause a significant breakdown of an existing biofilm (p≤0.028). Excretions from full grown maggots are more effective than those from young maggots.
This study shows for the first time that sterile maggot excretions of Lucilia sericata inhibit biofilm formation, prevent its further grow and break down existing biofilms. While biofilm formation on orthopaedic materials is a severe complication, this experimental study could indicate a new treatment for biofilm formation on infected biomaterials.
Correspondence should be addressed to Vasiliki Boukouvala at Department of Orthopaedic Surgery & Traumatology, University Hospital of Larissa, 110 Mezourlo, Larissa, GREECE. Tel: +30 2410 682722, Fax: +30 2410 670107, Email: malizos@med.uth.gr
