Larval Therapy and Larval Excretions/Secretions: A Potential Treatment for Biofilm in Chronic Wounds? A Systematic Review.

Chronic wounds present a global healthcare challenge and are increasing in prevalence, with bacterial biofilms being the primary roadblock to healing in most cases. A systematic review of the to-date knowledge on larval therapy's interaction with chronic-wound biofilm is presented here. The findings detail how larval therapy-the controlled application of necrophagous blowfly larvae-acts on biofilms produced by chronic-wound-relevant bacteria through their principle pharmacological mode of action: the secretion and excretion of biologically active substances into the wound bed. A total of 12 inclusion-criteria-meeting publications were identified following the application of a PRISMA-guided methodology for a systematic review. The findings of these publications were qualitatively analyzed to provide a summary of the prevailing understanding of larval therapy's effects on bacterial biofilm. A further review assessed the quality of the existing evidence to identify knowledge gaps and suggest ways these may be bridged. In summary, larval therapy has a seemingly unarguable ability to inhibit and degrade bacterial biofilms associated with impaired wound healing. However, further research is needed to clarify and standardize the methodological approach in this area of investigation. Such research may lead to the clinical application of larval therapy or derivative treatments for the management of chronic-wound biofilms and improve patient healing outcomes at a time when alternative therapies are desperately needed.

Evaluating nursing opinion and perception of maggot therapy for hard-to-heal wound management.

OBJECTIVE: Maggot therapy (MT) or larval debridement therapy is a recognised, effective but underutilised treatment for the management of hard-to-heal wounds and infected ulcers. It is available on NHS prescription in the UK, where wound management is predominantly nurse-led. Anecdotal reports and published literature suggest that nurses may be reluctant to utilise the therapy. The aim of this study was to evaluate the feelings and opinions of nurses regarding the use of MT. METHOD: The first stage of this mixed-methods study was a focus group held to discuss MT and opinions of specialist nurse clinicians. Next, an anonymised web-based online survey was launched through the Nursing Times journal and distributed through social media targeting all nurses. Finally, in-depth interviews were held with specialist and generalist nurses. RESULTS: Awareness of MT among all nurses was extremely high. A breakdown of results showed that MT was much more highly regarded by wound specialist nurses than non-wound specialist nurses. The latter exhibited a greater level of reluctance to administer the therapy, with almost one-third of these nurses surveyed saying they found maggots disgusting and that the idea of MT made their skin crawl. In-depth interviews revealed that a lack of knowledge about MT was a prime concern. CONCLUSION: Wound specialist nurses are more likely to embrace MT than non-wound nurse specialists, who report a varying degree of wariness to MT. Our study highlights a need for better education and training in MT for all nurses, to address issues with acceptance and willingness to treat or help treat patients with hard-to-heal wounds which are suitable for MT.

An exploration of public perceptions and attitudes towards maggot therapy.

OBJECTIVE: The aim of the study was to explore public opinion and perceptions of maggot therapy (larval therapy), a treatment option for hard-to-heal wounds. METHOD: The study used a mixed-method approach to obtain quantitative and qualitative data. A focus group was convened to explore opinions and views of maggot therapy with a small group of members of the public. Analysis of emerging themes from the focus group was used to design an anonymised web-based survey, which was made available online to members of the public through email and social media. RESULTS: The focus group participants identified four key themes concerning the acceptability of maggot therapy. The subsequent online survey was completed by 412 participants, analysis of which revealed some worries and fears. Only 36% of survey participants agreed that they would accept maggot therapy as a first choice for a hypothetical painful wound, although this number increased with wound severity. The most predominant concerns regarding maggot therapy were sensation and a feeling of disgust associated with the therapy. However, participants could see some benefits to maggot therapy. CONCLUSION: Our study showed that public perception of maggot therapy is varied. Survey participants expressed worries and fears associated with its use. However, positive relationships existed between knowledge scores and potential acceptability of maggot therapy, suggesting that information dissemination and education may be an important factor in public perception and acceptability of maggot therapy.

Naturally derived factors and their role in the promotion of angiogenesis for the healing of chronic wounds.

Chronic diseases such as vascular disease and diabetes are witnessing a global increase in prevalence. Such diseases often predispose patients to the development of severe, debilitating, chronic wounds. Angiogenesis, the formation of new capillaries from the pre-existing vascular network, is an essential component of wound healing and aberrant angiogenesis is evident in almost all chronic wounds. Natural products, derived from both plants and animals, provide a significant haven of compounds which have proved to be of great benefit to man and his ailments. Whilst significant advances have been made in the understanding of impaired angiogenesis in a non-healing wound, in the clinical setting, few effective agents exist that can expedite wound healing and closure. The lack of effective healing agents has led to a renewed interest in investigations into natural wound healing resources. In this review, we collate new evidence that details the potential for several natural compounds to promote angiogenesis and wound healing, most predominately via the up regulation of VEGF expression, that warrant urgent further investigation for development into new pro-angiogenic/wound healing therapies.

Disruption of Staphylococcus epidermidis biofilms by medicinal maggot Lucilia sericata excretions/secretions.

Chronic infections are commonly associated with biofilms formed by bacteria such as Staphylococcus epidermidis. With the increase in antibiotic resistant bacteria, maggot debridement therapy has been reintroduced for the treatment of chronic wounds. Studies have shown that the excretion/ secretions (ES) of Lucilia sericata larvae (maggots) contain many bioactive compounds which may contribute to the efficacy of maggot therapy. The present study evaluates the effect of L. sericata ES on the formation and disruption of S. epidermidis 1457 and 5179-R1 biofilms. These strains employ either polysaccharide intercellular adhesin (PIA) or accumulation associated protein (Aap) for intercellular adhesion. A semiquantitative biofilm assay was used to measure the formation/disruption of S. epidermidis 1457 and 5179-R1 biofilms by ES. ES activity was characterized according to concentration, incubation time and temperature, thermal stability, and size. Immunofluorescence microscopy was used to ascertain the effect of ES on PIA and Aap. In the presence of ES, S. epidermidis 1457 and 5179-R1 nascent biofilm formation was inhibited, and pre-formed biofilms disrupted. ES activity was temperature and time dependent, inactivated by heat treatment, and disruption depended on the mechanism of intercellular adhesion. The molecule(s) responsible was >10 kDa in size and appeared to have protease or glucosaminidase activity. ES interferes with S. epidermidis biofilm formation, specifically degrading factors employed in biofilm accumulation, which would increase bacterial susceptibility to antibiotics and the host's immune system. In purified form, ES-factors may have general applicability for the treatment or prevention of chronic biofilm infections caused by staphylococci.

Maggot therapy: the science and implication for CAM part II-maggots combat infection.

Maggot therapy employs the use of freshly emerged, sterile larvae of the common green-bottle fly, Phaenicia (Lucilia) sericata, and is a form of artificially induced myiasis in a controlled clinical situation. Maggot therapy has the following three core beneficial effects on a wound: debridement, disinfection and enhanced healing. In part II of this review article, we discuss clinical infections and the evidence supporting the potent antibacterial action of maggot secretions. Enhancement of wound healing by maggots is discussed along with the future of this highly successful, often controversial, alternative treatment.

Maggot Therapy: The Science and Implication for CAM Part I-History and Bacterial Resistance.

It is now a universally acknowledged fact that maggot therapy can be used successfully to treat chronic, long-standing, infected wounds, which have previously failed to respond to conventional treatment. Such wounds are typically characterized by the presence of necrotic tissue, underlying infection and poor healing. Maggot therapy employs the use of freshly emerged, sterile larvae of the common green-bottle fly, Phaenicia (Lucilia) sericata, and is a form of artificially induced myiasis in a controlled clinical situation. In this review article, we will discuss the role of maggots and their preparation for clinical use. Maggot therapy has the following three core beneficial effects on a wound: debridement, disinfection and enhanced healing. In part I we explore our current understanding of the mechanisms underlying these effects.

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).

Maggot therapy is a simple and highly successful method for cleansing infected and necrotic wounds. The use of maggots has become increasingly important in the treatment of non-healing wounds, particularly those infected with the multidrug-resistant pathogen, methicillin-resistant Staphylococcus aureus (MRSA). The increasing challenge concerning the treatment of MRSA infections and the recent finding of vancomycin-resistant strains of MRSA have elicited the search for novel antibacterial compounds and, in particular, investigations into the potent antibacterial mechanism(s) behind maggot therapy. In this study, we report that excretions/secretions (ES) from the blowfly, Lucilia sericata, exhibit potent, thermally stable, protease resistant antibacterial activity against MRSA in vitro. We describe the initial characterisation of two antibacterial factors from native ES of L. sericata. A small, <500 Da factor with significant antibacterial activity against MRSA was partially isolated using ultrafiltration techniques. The potent activity of this factor was comparable to that of native excretions/secretions. A larger, 0.5-3-kDa factor with significant activity against S. aureus was also partially characterised.