Excretions/Secretions from Bacteria-Pretreated Maggot Are More Effective against Pseudomonas aeruginosa Biofilms

BACKGROUND: Sterile larvae—maggots of the green bottle blowfly Lucilia sericata are employed as a treatment tool for various types of chronic wounds. Previous studies reported that excretions/secretions (ES) of the sterile larvae could prevent and remove the biofilms of various species of bacteria. In the present study we assessed the effect of ES from the larvae pretreated with Pseudomonas aeruginosa on the bacteria biofilms. METHODS AND FINDINGS: We investigated the effects of ES from the maggot pretreated with P. aeruginosa on the biofilms using microtitre plate assays and on bactericidal effect using the colony-forming unit (CFU) assay. The results showed that only 30 µg of the ES from the pretreated maggots could prevent and degrade the biofilm of P. aeruginosa. However, the CFU count of P. aeruginosa was not decrease when compared to the ES from non pretreated maggots in this study condition. It is suggested that the ES from the pretreated maggot was more effective against biofilm of P. aeruginosa than sterile maggot ES. CONCLUSIONS: Our results showed that the maggot ES, especially the bacteria-pretreated larva ES may provide a new insight into the treatment tool of the bacterial biofilms.