Bulletin of Entomological Research

Research Paper

An assessment of the antibacterial activity in larval excretion/secretion of four species of insects recorded in association with corpses, using Lucilia sericata Meigen as the marker species

K.M. Barnesa1 p1 c1, D.E. Gennarda1 and R.A. Dixona1

a1 Department of Forensic and Biomedical Sciences, University of Lincoln, Brayford Pool, Lincoln, LN6 7TS, UK

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.

(Accepted November 05 2009)

(Online publication March 22 2010)

Correspondence:

c1 Author for correspondence Fax: +44 (0) 114 2254449 E-mail: K.Barnes@shu.ac.uk

p1 Current address: Department of Biosciences, Sheffield Hallam University, City Campus, Sheffield, S1 1WB, UK