In vitro antibacterial activity of Lucilia sericata maggot secretions

Maggots of the green blowfly, Lucilia sericata, are used as an alternative to surgical intervention and long-term antiseptic therapy for the treatment of chronic wounds. The secretions of maggots are known to have antibacterial properties. To quantify the bactericidal effect of secretions from larvae of L. sericata, an in vitro test model based on the modified European quantitative suspension test (EN 1040) was developed, in which a co-culture of maggots and bacteria (Micrococcus luteus,Escherichia coli, methicillin-sensitive Staphylo-coccus aureus) in tryptic soy broth was tested. The numbers of bacterial colonies with and without maggot exposure were compared after 24, 48 and 72 h of exposure. The mean log(10) reduction factor (RF) for bacterial elimination per maggot was >4 at all examined times for all tested bacteria. Thus, maggot secretion fulfilled the required definitions of an antiseptic. In addition, the maggots' ability to ingest bacteria was also evaluated. Maggots contained viable bacteria after 48 h of contact with the respective organisms. These maggots also continued excreting bacteria. Therefore, maggots should be disposed of after use as they must be regarded as medical waste.