Bacteria Ingestion by Blowfly Larvae: An in vitro Study

Abstract

Background: Maggot debridement therapy is the medical use of live fly larvae for cleaning chronic and infected wounds, removing devitalized tissue and decreasing the risk of infection. Maggot-derived proteins are able to kill bacteria, and proteolytic enzymes are responsible for the liquefying of necrotic tissue. Objective: The aim of this study is to investigate bacterial ingestion by larvae roaming free on bacterial agar, compared to those larvae contained within vinyl bags. Methods: Free-roaming sterile larvae of Lucilia sericata and larvae contained in vinyl bags were fed on Escherichia coli producing green fluorescent protein (GFP). The time interval to the onset of fluorescent maggots was determined. At different time intervals, maggots were sacrificed, washed in sterile saline, sagittally cut in frozen sections and examined under a microscope with UV light. Results: After feeding on GFP-labelled E. coli, maggots roaming free on bacterial lawn agar demonstrated fluorescence after 3 min, maggots entrapped in vinyl bags after 25 min. In the sagittal frozen sections, the highest fluorescent intensity was detected in the larvae’s rostral part of the alimentary tract, the crop and the anterior midgut. Conclusion: In an in vitro setting, digestion and ingestion of whole or disintegrated bacteria is accomplished within minutes. The vinyl bag’s permeable membrane clearly causes a delay of this process.

Maggot Debridement Therapy in the Treatment of Chronic Wounds in a Military Hospital Setup in Turkey

“…andmethicillin-resistant strains of S. aureus [22, 24]. It was also shown that E. coli were destroyed [25] in the midgut during the passage through the maggot’s digestive tract [26]. These findings are consistent with our results which show that maggots are able to combat clinical infections in a variety of wounds.…”

Lucifensin, the long-sought antimicrobial factor of medicinal maggots of the blowfly Lucilia sericata

“…The application of sterile larvae to an infected non-healing wound results in the removal of necrotic tissue (debridement), disinfection, rapid elimination of infecting microorganisms including methicillinresistant Staphylococcus aureus (MRSA) and enhancement of the healing process [1,2]. It has been suggested that the antimicrobial action results from both larval ingestion of wound bacteria [3], which are killed as they pass through the larvae digestive tracts [4], and by antimicrobial activity of larvae components, including salivary gland secretions and faecal waste products [5]. Not surprisingly, many attempts have been made to isolate and identify in the excretion/secretion (ES) antimicrobial agents responsible for suppressing MRSA and other bacteria in infected wounds.…”

Comparison of Bacterial Diversity in Wheat Bran and in the Gut of Larvae and Newly Emerged Adult of Musca domestica (Diptera: Muscidae) by Use of Ethidium Monoazide Reveals Bacterial Colonization

“…In contrast to the mutually beneÞcial relationship between bacteria and its insect host, such as termites and aphids, house ßy larvae may digest bacteria as a nutrient source and this phenomenon seems to be an ancestral trait of Diptera Cyclorrhapha (Lemos and Terra 1991). Previous studies have indicated that Ͼ80% of bacteria in food would be hydrolyzed and digested by a combination of low pH, lysozyme, cathepsin-DÐlike protease, and aminopeptidase in the larval gut (Greenberg and Klowden 1972, Mumcuoglu et al 2001, Lerch et al 2003, Blahovec et al 2006.…”