Larval therapy for a leg ulcer with methicillin-resistant Staphylococcus aureus

A molecular approach to maggot debridement therapy with Lucilia sericata and its excretions/secretions in wound healing

Chronic wounds caused by underlying physiological causes such as diabetic wounds, pressure ulcers, venous leg ulcers and infected wounds affect a significant portion of the population. In order to treat chronic wounds, a strong debridement, removal of necrotic tissue, elimination of infection and stimulation of granulation tissue are required. Maggot debridement therapy (MDT), which is an alternative treatment method based on history, has been used quite widely. MDT is an efficient, simple, cost-effective and reliable biosurgery method using mostly larvae of Lucilia sericata fly species. Larvae can both physically remove necrotic tissue from the wound site and stimulate wound healing by activating molecular processes in the wound area through the enzymes they secrete. The larvae can stimulate wound healing by activating molecular processes in the wound area through enzymes in their excretions/secretions (ES). Studies have shown that ES has antibacterial, antifungal, anti-inflammatory, angiogenic, proliferative, hemostatic and tissue-regenerating effects both in vivo and in vitro. It is suggested that these effects stimulate wound healing and accelerate wound healing by initiating a direct signal cascade with cells in the wound area. However, the enzymes and peptides in ES are mostly still undefined. Examining the molecular content of ES and the biological effects of these ingredients is quite important to illuminate the molecular mechanism underlying MDT. More importantly, ES has the potential to have positive effects on wound healing and to be used more as a therapeutic agent in the future, so it can be applied as an alternative to MDT in wound healing.

Therapeutic arthropods and other, largely terrestrial, folk-medicinally important invertebrates: a comparative survey and review

Traditional healing methods involving hundreds of insect and other invertebrate species are reviewed. Some of the uses are based on the tenet of "similia similibus" (let likes be cured by likes), but not all non-conventional health promoting practices should be dismissed as superstition or wishful thinking, for they have stood the test of time. Two questions are addressed: how can totally different organ systems in a human possibly benefit from extracts, potions, powders, secretions, ashes, etc. of a single species and how can different target organs, e.g. bronchi, lungs, the urinary bladder, kidneys, etc. apparently respond to a range of taxonomically not even closely related species? Even though therapeutically used invertebrates are generally small, they nevertheless possess organs for specific functions, e.g. digestion, gas exchange, reproduction. They have a nervous system, endocrine glands, a heart and muscle tissue and they contain a multitude of different molecules like metabolites, enzymes, hormones, neurotransmitters, secretions, etc. that have come under increased scientific scrutiny for pharmacological properties. Bearing that in mind it seems likely that a single species prepared and used in different ways could have a multitude of uses. But how, for example, can there be remedies for breathing and other problems, involving earthworms, molluscs, termites, beetles, cockroaches, bugs, and dragonflies? Since invertebrates themselves can suffer from infections and cancers, common defence reactions are likely to have evolved in all invertebrates, which is why it would be far more surprising to find that each species had evolved its own unique disease fighting system. To obtain a more comprehensive picture, however, we still need information on folk medicinal uses of insects and other invertebrates from a wider range of regions and ethnic groups, but this task is hampered by western-based medicines becoming increasingly dominant and traditional healers being unable and sometimes even unwilling to transmit their knowledge to the younger generation. However, collecting and uncontrolled uses of therapeutic invertebrates can put undue pressure on certain highly sought after species and this is something that has to be borne in mind as well.

Maggot debridement therapy with Lucilia cuprina: a comparison with conventional debridement in diabetic foot ulcers

This is prospective case-control study of more than 18 months performed to assess the effectiveness of maggot debridement therapy (MDT) with the sterile larvae of Lucilia cuprina (a tropical blowfly maggot) for the treatment of diabetic foot ulcers. Literature thus far has only reported results with the temperate maggot, Lucilia sericata. This study documents outcome in diabetic foot wounds treated with maggot debridement versus those treated by conventional debridement alone. In this series of 29 patients treated with MDT, 14 wounds were healed, 11 were unhealed and 4 were classified under others. The control group treated by conventional debridement had 30 patients of which 18 wounds were healed, 11 unhealed and 1 classified under others. There was no significant difference in outcome between the two groups. The conclusion that can be made from this study is that MDT with L. cuprina is as effective as conventional debridement in the treatment of diabetic foot ulcers. It would be a feasible alternative to those at high risk for surgery or for those who refuse surgery.

Selective antimicrobial activity of maggots against pathogenic bacteria

Maggot therapy, also known as biosurgery, is an ancient method for the healing of chronic infected wounds. Although clinicians have reported on the beneficial activities of the Lucilia sericata larvae that have been used for healing chronic wounds, the selectivity of this therapy against the different pathogenic micro-organisms that are found in chronic wounds has never been analysed. In the present study, we have investigated the in vitro activities of larval excreta/secreta both against selected bacterial strains that frequently occur in chronically infected wounds, and against bacteria isolated directly from the larvae and their excreta/secreta. Additionally, the antibacterial activities were investigated in in vivo studies, by comparing bacterial diversity in wounds before and after the application of L. sericata larvae. In conclusion, larval therapy is highly recommended, particularly for the treatment of wounds infected with Gram-positive bacteria, like Staphylococcus aureus, but less so for wounds infected with Gram-negative bacteria, especially Proteus spp. and Pseudomonas spp. strains. Bacteria from the genus Vagococcus were resistant to the maggot excreta/secreta.

Larval therapy from antiquity to the present day: mechanisms of action, clinical applications and future potential

When modern medicine fails, it is often useful to draw ideas from ancient treatments. The therapeutic use of fly larvae to debride necrotic tissue, also known as larval therapy, maggot debridement therapy or biosurgery, dates back to the beginnings of civilisation. Despite repeatedly falling out of favour largely because of patient intolerance to the treatment, the practice of larval therapy is increasing around the world because of its efficacy, safety and simplicity. Clinical indications for larval treatment are varied, but, in particular, are wounds infected with multidrug-resistant bacteria and the presence of significant co-morbidities precluding surgical intervention. The flies most often used in larval therapy are the facultative calliphorids, with the greenbottle blowfly (Lucilia sericata) being the most widely used species. This review summarises the fascinating and turbulent history of larval therapy from its origin to the present day, including mechanisms of action and evidence for its clinical applications. It also explores future research directions.

Cost of managing chronic wounds in the UK, with particular emphasis on maggot debridement therapy

The importance of debridement in wound healing is well established. This review calculates the cost savings that might be achieved when using maggot debridement therapy on chronic wounds instead of autolytic debridement.

Maggots and wound healing: an investigation of the effects of secretions from Lucilia sericata larvae upon the migration of human dermal fibroblasts over a fibronectin-coated surface

Lucilia sericata larvae, or greenbottle fly maggots, placed within chronic wounds have been observed to remove necrotic tissue and infection. They are also believed to actively promote granulation tissue formation. Interactions between fibroblasts and the surrounding extracellular matrix play a crucial role in tissue formation, influencing fibroblast proliferation, migration, and tissue remodeling. For example, the strength of cell adhesion to surfaces coated with extracellular matrix influences cell motility. L. sericata larval excretory/secretory products having previously been shown to modify fibroblast adhesion to collagen and particularly fibronectin, it was hypothesized that these products would alter fibroblast migration. This was investigated using a two-dimensional in vitro wound assay, time-lapse digital photography, enzyme class-specific substrates and inhibitors, and gel electrophoresis. Results showed that L. sericata excretory/secretory products promoted fibroblast migration upon a fibronectin-coated surface. This was related to the degradation of fibronectin by serine proteinases within maggot excretion/secretions. The presence of a metalloproteinase activity may also have played a role. Thus, a possible mechanism by which maggots enhance tissue formation within wounds may be via the promotion of fibroblast motility, providing for a wider distribution of viable fibroblasts.

Rearing larvae of Lucilia sericata for chronic ulcer treatment--an improved method

Larval therapy is a biological 'dressing' for chronic ulcers which is used for debridement, to initiate healing and to reduce bacteria and unpleasant odour. One condition for being able to employ larval therapy is access to disinfected larvae of good quality. We therefore started rearing Lucilia sericata larvae in 1998. Rearing necrophagous larvae in a hospital setting makes it essential to control odour. The improvement of the method includes the use of a controlled, humid, warm environment with artificial light and inexpensive disposable material, as well as the use of ready-made, constantly available and aseptically produced nutrition for feeding larvae and flies. With equipment such as a refrigerator and freezer, larval food is kept fresh and odour-free and chloramine solution is used to disinfect the eggs and thus the larvae. Adhering to a proposed weekly working schedule makes the rearing procedure effective and reliable.

Maggot therapy for foot and leg wounds

Maggot debridement therapy has been used for more than 70 years to treat nonhealing soft tissue wounds. Blowfly larvae are used to debride, disinfect, and promote healing of chronic wounds. The use of maggot therapy is on the rise, owing to recognized limitations in our current medical and surgical wound care options. Anecdotal evidence of maggot therapy efficacy is plentiful, but large prospective comparative clinical trials are desperately needed. Until data from such studies become available, treatment criteria and safety data must be derived from retrospective studies, case series, and other published accounts. Based on these limited sources of data,treatment guidelines are proposed for the safe and effective use of maggots for treating problematic foot and leg wounds.

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.

Presurgical maggot debridement of soft tissue wounds is associated with decreased rates of postoperative infection

Postoperative complications were assessed for all patients who received presurgical maggot debridement therapy (MDT) and for a matched group of patients who did not. Ten wounds were debrided by maggots within 1-17 days prior to surgical closure. Debridement was effective in all cases, and there were no postoperative wound infections. Six (32%) of 19 wounds not treated presurgically with MDT developed postoperative wound infections (95% CI, 10%-54%; P<.05). Presurgical MDT was effective in preparing the wound bed for surgical closure, without increased risk of postsurgical wound infection.

Wound care in geriatrics

Wound care is a crucial aspect in caring for the geriatric population. It is important to recognize a wound when it begins and know the proper treatment once a wound develops. First, it is important to assess the wound and determine the type of wound that is being dealt with. One must establish whether the wound is acute of chronic. Then a proper treatment plan must be devised. This article will take you through step by step process of different types of wounds and the proper treatment of those wounds that commonly occur within the geriatric population.

Maggot therapy for wound debridement in a traumatic foot-degloving injury: a case report

A 43-year-old man was treated for a traumatic degloving injury to his foot with a transmetatarsal amputation and wound care because of the extensive soft tissue loss. After biweekly sharp debridements in the office for 4 weeks, very minimal skin ingrowth was noted. Maggot therapy was then implemented for a 48-hour treatment and a second treatment for 72 hours to help reduce excessive fibrosis and to painlessly debride the tissues to expose the granular base. Daily dressing changes for the next 6 weeks successfully allowed complete wound closure without any additional interventions. During the follow-up course, no complications were encountered and the patient has returned to ambulation with the use of a cane.

Maggots and wound healing: an investigation of the effects of secretions from Lucilia sericata larvae upon interactions between human dermal fibroblasts and extracellular matrix components

BACKGROUND

Through clinical observation, Lucilia sericata (greenbottle fly) larvae are credited with exerting the following beneficial effects upon a chronic nonhealing wound: removal of necrotic tissue ('debridement'), disinfection of the wound and active promotion of granulation tissue formation. As a major cellular component of granulation tissue, fibroblasts play an extensive role in healing. The composition of extracellular matrix (ECM) located in the wound is another important factor, partaking in a dynamic feedback loop with the fibroblasts that produce it. Fibroblast-ECM interactions therefore exert considerable influence upon new tissue formation.

OBJECTIVES

To investigate the effects of L. sericata larval excretory/secretory products (ES) upon the behaviour of fibroblasts, seeded upon ECM component surfaces.

METHODS

ES were collected by washing freshly hatched larvae in phosphate-buffered saline. Human dermal neonatal fibroblast cells were seeded upon fibronectin- or collagen-coated surfaces, together with untreated (or 'native') ES, heat-treated ES, or no ES (ES blank). Following incubation, fibroblast adhesion was determined using an adenosine triphosphate assay and, for confirmation, a total nucleic acid content assay. Cell spreading was observed using microscopy. The effect of ES upon fibronectin structure was observed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Peptide sequencing of suspected fibronectin fragments was performed using an 'electrospray' type time of flight mass spectrometer and 'Peptident' database search.

RESULTS

ES significantly reduced fibroblast adhesion to both fibronectin and, to a lesser extent, collagen. Cell spreading was also reduced, yet cells remained viable. For both spreading and adhesion, heat-treated ES exerted significantly less activity than native, untreated ES. However, they still exhibited significant activity when compared with the ES blank. ES appeared to modify fibroblast adhesion indirectly via proteolytic fragmentation of the fibronectin protein surface.

CONCLUSIONS

L. sericata larval secretions modify fibroblast adhesion and spreading across ECM protein surfaces, while keeping cells viable. Proteolytic activity of the ES played a significant role. If transferred to the wound situation, such alteration of fibroblast-ECM interactions may enhance new tissue formation.

Maggot versus conservative debridement therapy for the treatment of pressure ulcers

To define the efficacy and safety of maggot therapy, a cohort of 103 inpatients with 145 pressure ulcers was evaluated. Sixty-one ulcers in 50 patients received maggot therapy at some point during their monitored course; 84 ulcers in 70 patients did not. Debridement and wound healing could be quantified for 43 maggot-treated wounds and 49 conventionally treated wounds. Eighty percent of maggot-treated wounds were completely debrided, while only 48% of wounds were completely debrided with conventional therapy alone (p=0.021). Within 3 weeks, maggot-treated wounds contained one-third the necrotic tissue (p = 0.05) and twice the granulation tissue (p < 0.001), compared to non-maggot-treated wounds. Of the 31 measurable maggot-treated wounds monitored initially during conventional therapy, necrotic tissue decreased 0.2 cm(2) per week during conventional therapy, while total wound area increased 1.2 cm(2) per week. During maggot therapy, necrotic tissue decreased 0.8 cm(2) per week (p = 0.003) and total wound surface area decreased 1.2 cm2 per week (p = 0.001). Maggot therapy was more effective and efficient in debriding chronic pressure ulcers than were the conventional treatments prescribed. Patients readily accepted maggot therapy, and adverse events were uncommon.

Clinical applications for maggots in wound care

Maggot debridement therapy (MDT) was first introduced in the US in 1931 and was routinely used there until mid-1940s in over 300 hospitals. With the advent of antibacterials, maggot therapy became rare until the early 1990s, when it was re-introduced first in the US, and later in Israel, the UK, Germany, Sweden, Switzerland, Ukraine and Thailand. Sterile maggots of the green bottle fly, Lucilia (Phaenicia) sericata, are used for MDT. Up to 1000 maggots are introduced in the wound and left for 1 to 3 days. MDT could be used for any kind of purulent, sloughy wound on the skin, independent of the underlying diseases or the location on the body for ambulatory as well as for hospitalized patients. One of the major advantages of MDT is that the maggots separate the necrotic tissue from the living tissue, making a surgical debridement easier. In 80 to 95% of the cases, a complete or significant debridement of the wound is achieved. As therapy progresses, new layers of healthy tissue are formed over the wounds. The offensive odor emanating from the necrotic tissue and the intense pain accompanying the wound decrease significantly. In a significant number of patients, an immediate amputation can be prevented as a result of MDT. In other cases, a more proximal amputation could be avoided. It is also possible that in patients with deep wounds, where septicemia is a serious threat, this can be prevented as a result of MDT. The majority of patients do not complain of any major discomfort during the treatment. Psychological and esthetic considerations are obvious. Maggots can occasionally cause a tickling or itching sensation. Approximately 20 to 25% of the patients with superficial, painful wounds, complain of increased pain during treatment with maggots, and are treated with analgesics. MDT has been proven to be an effective method for cleaning chronic wounds and initiating granulation. It is a simple, efficient, well tolerated and cost-effective tool for the treatment of wounds and ulcers, which do not respond to conventional treatment and surgical intervention.