Induction of antibacterial activity in larvae of the blowflyLucilia sericataby an infected environment

Abstract

Maggot debridement therapy (MDT) is a method for the treatment of intractable, infected and necrotic wounds. In MDT, sterile larvae of Lucilia sericata Meigen (Diptera: Calliphoridae) are applied to infected wounds, where they exert antibacterial effects. Once the larvae are placed in the wound, they are no longer germ-free. This study analysed the influence of infected environments on larval antibacterial activities. Sterile larvae were mixed in a test tube containing a bacterial suspension of Staphylococcus aureus or Pseudomonas aeruginosa, transferred to liver puree agar, and incubated at 25 °C for set periods. To collect the larval extracts, the incubated larvae were transferred to a test tube containing phosphate buffered saline (PBS), cut into multiple pieces with scissors, and centrifuged. The supernatant was used to test antibacterial activities. The results showed that infected larvae had better antibacterial capacities than sterile larvae. Antibacterial activities were induced by pretreatment with a single bacterial species, S. aureus or P. aeruginosa, within 24 h and 12 h, respectively, and disappeared after 36 h. The activities were effective against S. aureus, but not against P. aeruginosa. This natural infection model is very similar to the clinical wound context in MDT and will be a powerful tool with which to study the antibacterial activities of L. sericata larvae in MDT.

Mechanisms of Maggot‐Induced Wound Healing: What Do We Know, and Where Do We Go from Here?

“…Antimicrobial activity has been seen even against highly antibiotic-resistant bacteria [40, 43] and against the protozoan Leishmania parasite [44, 45]. Kawabata et al [46] demonstrated that the antimicrobial activity could be modified by exposure to microbial challenges (as is the case with many innate immunodefense peptides).…”

Advances in Myiasis Treatment

“…The inducible nature of larval antibacterial activity had been reported previously, but has also been verified yet again more recently, with results indicating that that infected larvae have much better antibacterial capacities than sterile larvae [7]. Researchers argue that the clinical wound situation would enable larvae in the infected environment to influence production of their antibacterial activities.…”

Insect natural products and processes: New treatments for human disease

“…There are many reports showing that the secretions of maggots have anti-bacterial properties (eg. Simmons, 1935;Pavillard and Wright, 1957;Thomas et al, 1999;Kawabata et al, 2010). Kawabata et al (2010) showed that some of these factors are induced in L. sericata by an infected environment.…”

“…Simmons, 1935;Pavillard and Wright, 1957;Thomas et al, 1999;Kawabata et al, 2010). Kawabata et al (2010) showed that some of these factors are induced in L. sericata by an infected environment. A few of the anti-bacterial factors involved have now been identified and characterised (Table 6).…”