Detection and partial characterisation of two antibacterial factors from the excretions/secretions of the medicinal maggot Lucilia sericata and their activity against methicillin-resistant Staphylococcus aureus (MRSA)

The antibacterial potency of the medicinal maggot, Lucilia sericata (Meigen): Variation in laboratory evaluation

“…From our results and those of other researchers, it is vital to select optimal conditions in which to detect antibacterial activity in L. sericata ES (Thomas et al, 1999;Bexfield et al, 2004;Jaklic et al, 2008;Cazander et al, 2009b). Whilst it is important to use media with a sufficiently high nutritional content for normal bacterial growth in the control vessel, it is also important that the amount and type of media employed is not detrimental to the antibacterial activity exhibited by the ES.…”

“…Consequently, the different concentrations of ES and types of media employed in the LCAs will have contributed to the variation in results to date reported by previous researchers (Thomas et al, 1999;Bexfield et al, 2004;Jaklic et al, 2008;Cazander et al, 2009b).…”

“…A number of studies have demonstrated that bacteria, such as Escherichia coli are consumed and then eradicated in the acidic midgut of L. sericata larvae (Robinson and Norwood, 1934;Greenberg, 1968;Mumcuoglu et al, 2001;Daeschlein et al, 2007) and that the externalised larval excretion/secretion (ES) can reduce the viability of a number of Gram-negative and Gram-positive organisms (Simmons, 1935;Thomas et al, 1999;Bexfield et al, 2004;Kerridge et al, 2005;Bexfield et al, 2008;Jaklic et al, 2008;van der Plas et al, 2008;Cazander et al, 2009a;Harris et al, 2009). …”

“…To date, the quantification of the antibacterial effectiveness of L. sericata ES has been most successful using liquid culture assays (LCAs) (Bexfield et al, 2004;Jaklic et al, 2008). However, a review of studies provided contradictory results on the duration and potency of antibacterial activity against common wound bacterial species.…”

“…However, a review of studies provided contradictory results on the duration and potency of antibacterial activity against common wound bacterial species. For example, some research demonstrated L. sericata ES inhibited growth of Pseudomonas aeruginosa over a 24-hour period at an estimated concentration of 5g larvae per ml (Bexfield et al, 2004) whereas others reported a prolonged lag phase of 5-6 hours at an estimated concentration of 7.5 g larvae per ml (Jaklic et al, 2008) or either partial or no inhibition of P. aeruginosa (Thomas et al, 1999;Cazander et al, 2009b).…”