Abstract

The relative antibacterial activities of excretion/secretion (ES) from two carrion-feeding
insects, Calliphora vicina Robineau-Desvoidy and Dermestes maculatus
DeGeer, and a detritivore, Tenebrio molitor Linnaeus, were compared to that of
Lucilia sericata Meigen, a species with ES of known antibacterial capacity, in order
to explore the antimicrobial potential of other carrion and detritivore species.
Viable counts were used to assess time-kill of ES against five bacterial species,
Staphylococcus aureus, Escherichia coli, Bacillus cereus, Pseudomonas aeruginosa and
Proteus mirabilis. Antibacterial activity was recorded in all four insect species
although T. molitor and D. maculatus were the most effective in controlling growth
of P. mirabilis. The blowflies were more effective in controlling a wider range of
both Gram-positive and Gram-negative bacteria. The larval ES from all species was
shown to reduce bacterial growth rate although differences in antibacterial
spectrum were noted and the degree of potency varied between the four species.
These differences may be explained ecologically by the different colonisation times
of each insect species on the corpse. Overall, this study demonstrates that research
into other carrion-feeding insect species has potential to provide an increased
source of antimicrobial chemicals to broaden the range of bacterial species beyond
that currently controlled using L. sericata.