Maggot debridement therapy as primary tool to treat chronic wound of animals

The role of medical-grade maggots in facilitating healing of diabetic foot ulcers in Kano, northern Nigeria: a case series

OBJECTIVE

Approximately 13% of people living with diabetes develop one or more ulcers during the course of the disease, and diabetic foot ulcer (DFU) is responsible for >60% of lower limb amputations worldwide. This case series aimed to demonstrate the effectiveness of medical-grade maggots on DFUs in promoting wound healing and reducing related hospital stays in northern Nigeria.

METHOD

Maggot debridement therapy (MDT) was applied to the DFUs of patients who consented to this treatment between January-August 2021 at the Orthopaedic Unit of the Aminu Kano Teaching Hospital (AKTH), Kano, Nigeria. Sterile first instar larvae of Lucilia sericata were obtained indigenously and applied using the confinement (free-range) method under aseptic procedure.

RESULTS

A total of 15 patients with DFUs of Wagner classification grades III (33.3%) and IV (66.7%), were seen and documented. The patients included 10 (66.7%) females and five (33.3%) males, giving a female:male ratio of 2:1. The mean age (±standard deviation) of the respondents was 51.6±10.8 years. The surface area of the wounds ranged from 24-140cm2, with a median value of 75cm2. Among the patients, 60% had two cycles of MDT, with a median duration of five days. Most of the wounds (53.3%) were debrided within five days; 13.3% (two wounds) took seven days to be fully debrided. A paired sample t-test showed a statistically significant association between wound surface area and therapy duration (t=8.0; p=0.000) and between wound surface area and cycles of therapy (t=8.3; p=0.000). Before maggot application, 14 (93.3%) DFUs were completely (100%) covered with slough and only one (6.7%) was 95% covered with slough. After maggot application, 10 (66.7%) wounds were completely debrided while five (33.3%) wounds required bedside surgical debridement to achieve complete debridement. A paired sample t-test showed statistically significant difference between the pre- and post-MDT slough covering the wounds (t=45.1; p=0.000).

CONCLUSION

In this case series, MDT was successfully used in the debridement of DFUs, which facilitated the healing process with an encouraging clinical outcome.

Maggot debridement therapy and complementary wound care: a case series from Nigeria

Objective:

Maggot debridement therapy (MDT) is an emerging procedure involving the application of sterile maggots of the Dipteran species (commonly Lucilia sericata) to effect debridement, disinfection and promote healing in wounds not responding to antimicrobial therapy. Data on MDT in sub-Saharan Africa (including Nigeria) are scarce. This study aimed to use medicinal grade maggots as a complementary method to debride hard-to-heal necrotic ulcers and thereby promote wound healing.

Method:

In this descriptive study, we reported on the first group of patients who had MDT at Aminu Kano Teaching Hospital (AKTH), a tertiary hospital in northern Nigeria. The first instar larvae of Lucilia sericata were applied using the confinement (free-range) maggot therapy dressing method under aseptic conditions.

Results:

Diabetic foot ulcer (DFU) grade III–IV constituted more than half of the wounds (53.3%), followed by necrotising fasciitis (30%), and post-traumatic wound infection (10%). Others (6.7%, included pyomyositis, surgical site infection and post traumatic wound infection). The median surface area of the wounds was 56cm 2 . Of the 30 patients, half (50%) had two MDT cycles with a median time of four days. Of the wounds, 22 (73%) were completely debrided using maggots alone while eight (27%) achieved complete debridement together with surgical debridement. Wound culture pre-MDT yielded bacterial growth for all the patients and Staphylococcus aureus was the predominant isolate in 17 wounds (56.7%) while Pseudomonas aeruginosa and Streptococcus pyogenes were predominant in five wounds (16.7%) each. Only four (13.3%) wound cultures yielded bacterial growth after MDT, all Staphylococcus aureus.

Conclusion:

A good prognosis was achieved post-MDT for various wounds. MDT effectively debrides and significantly disinfects wounds involving different anatomical sites, thus enhancing wound healing and recovery. MDT is recommended in such wounds.

Local wound management: A review of modern techniques and products

Management of wounds is a commonly performed and essential aspect of small animal veterinary medicine. Appropriate wound management is a difficult art to master, due to the inherent complexity of the clinical scenario, as well as the ever-evolving nature of the field with the constant addition of new products and techniques. This article reviews key concepts that may help the practitioner better understand the natural process of wound healing, factors that delay healing and strategies to help improve the local wound environment to make it more conducive to healing during open wound management. The concept of wound bed preparation is defined before common local wound management strategies, such as wound lavage and debridement, are discussed in more detail. Key aspects of the management of biofilms and appropriate use of antimicrobial agents are also reviewed. Finally, the concept of moist wound healing and its impact in modern wound management is explained before a broad variety of types of wound dressings are reviewed, with a particular focus on active dressings.

Análisis comparativo de la actividad antimicrobiana de secreciones y excreciones larvales de Calliphora vicina y Sarconesiopsis magellanica (Diptera: Calliphoridae)

Introducción.

La creciente resistencia bacteriana a los antibióticos representa una amenaza mundial de salud pública. Las excreciones y secreciones larvarias derivadas de moscas necrófagas de la familia Calliphoridae podrían configurar una fuente promisoria para contrarrestar sus efectos.

Objetivo.

Comparar la actividad antimicrobiana de las excreciones y secreciones larvarias nativas, y de las mayores y menores de 10 kDa de Calliphora vicina y Sarconesiopsis magellanica (Diptera: Calliphoridae).

Materiales y métodos.

El bioensayo se hizo a partir de la técnica de turbidimetría y en el caso de las excreciones y secreciones menores de 10 kDa se determinó la concentración inhibitoria mínima (CIM).

Resultados.

Las excreciones y secreciones nativas y las menores de 10 kDa de C. vicina y S. magellanica, evidenciaron una potente actividad antibacteriana contra tres cepas de Staphylococcus aureus y cuatro bacterias Gram negativas, siendo las menores de 10 kDa más efectivas que las nativas en las dos especies de moscas evaluadas. Además, las menores de 10 kDa presentaron la misma efectividad, aunque en las pruebas de CIM se observó que las de S. magellanica fueron más potentes en todas las bacterias evaluadas, excepto contra la cepa de S. aureus ATCC 25923. Las mayores de 10 kDa no inhibieron el crecimiento bacteriano.

Conclusión.

Los resultados validaron, en general, que estas sustancias son fuente importante para el aislamiento y la caracterización de agentes antimicrobianos.

Management of severe burn injuries with novel treatment techniques including maggot debridement and applications of acellular fish skin grafts and autologous skin cell suspension in a dog

CASE DESCRIPTION

A 3-year-old 27-kg female spayed American Bulldog with severe burn injuries caused by a gasoline can explosion was evaluated.

CLINICAL FINDINGS

The dog had extensive partial- and full-thickness burns with 50% of total body surface area affected. The burns involved the dorsum extending from the tail to approximately the 10th thoracic vertebra, left pelvic limb (involving 360° burns from the hip region to the tarsus), inguinal area bilaterally, right medial aspect of the thigh, and entire perineal region. Additional burns affected the margins of the pinnae and periocular regions, with severe corneal involvement bilaterally.

TREATMENT AND OUTCOME

The dog was hospitalized in the hospital's intensive care unit for 78 days. Case management involved provision of aggressive multimodal analgesia, systemic support, and a combination of novel debridement and reconstructive techniques. Debridement was facilitated by traditional surgical techniques in combination with maggot treatment. Reconstructive surgeries involved 6 staged procedures along with the use of novel treatments including applications of widespread acellular fish (cod) skin graft and autologous skin cell suspension.

CLINICAL RELEVANCE

The outcome for the dog of the present report highlighted the successful use of maggot treatment and applications of acellular cod skin and autologous skin cell suspension along with aggressive systemic management and long-term multimodal analgesia with debridement and wound reconstruction for management of severe burn injuries encompassing 50% of an animal's total body surface area.

The effect of Lucilia sericata larval excretion/secretion (ES) products on cellular responses in wound healing

Chronic wounds are still regarded as a serious public health concern, which are on the increase mainly due to the changes in life styles and aging of the human population. There are different types of chronic wounds, each of which requires slightly different treatment strategies. Nevertheless, wound bed preparation is included in treatment of all types of chronic wounds and involves tissue debridement, inflammation, and infection control, as well as moisture balance and epithelial edge advancement. Maggot therapy (MT) is a form of biological debridement which involves the application of live medical grade Lucilia sericata (Meigen, 1826) (Diptera: Calliphoridae) larvae. Whereas it was initially thought to act mainly through debridement, today MT is known to influence all four overlapping physiological phases of wound repair: homeostasis, inflammation, proliferation, and remodelling/maturing. During MT, medical-grade larvae are applied either freely or enclosed in tea-bag like devices (biobag) inside the wounds, which suggests that larva excretion/secretion (ES) products can facilitate the healing processes directly without the need of direct contact with the larvae. This review summarizes the relevant literature on ES-mediated effects on the cellular responses involved in wound healing.

Effect of Temperature on Heart Rate for Phaenicia sericata and Drosophila melanogaster with Altered Expression of the TrpA1 Receptors

The transient receptor potential (TrpA-ankyrin) receptor has been linked to pathological conditions in cardiac function in mammals. To better understand the function of the TrpA1 in regulation of the heart, a Drosophila melanogaster model was used to express TrpA1 in heart and body wall muscles. Heartbeat of in intact larvae as well as hearts in situ, devoid of hormonal and neural input, indicate that strong over-expression of TrpA1 in larvae at 30 or 37 °C stopped the heart from beating, but in a diastolic state. Cardiac function recovered upon cooling after short exposure to high temperature. Parental control larvae (UAS-TrpA1) increased heart rate transiently at 30 and 37 °C but slowed at 37 °C within 3 min for in-situ preparations, while in-vivo larvae maintained a constant heart rate. The in-situ preparations maintained an elevated rate at 30 °C. The heartbeat in the TrpA1-expressing strains could not be revived at 37 °C with serotonin. Thus, TrpA1 activation may have allowed enough Ca2+ influx to activate K(Ca) channels into a form of diastolic stasis. TrpA1 activation in body wall muscle confirmed a depolarization of membrane. In contrast, blowfly Phaenicia sericata larvae increased heartbeat at 30 and 37 °C, demonstrating greater cardiac thermotolerance.

Changing attitudes toward maggot debridement therapy in wound treatment: a review and discussion

Maggot debridement therapy is the real-time placement of maggots into a wound by health professionals for the treatment of diabetic ulcers or hard-to-heal wounds infected with antibiotic-resistant bacteria. Maggot debridement therapy shortens healing and disinfects wounds. This paper is a literature review of maggot debridement therapy in the clinical setting today and addresses the costs and benefits of this therapy. It includes recommendations to engage healthcare providers and increase awareness of this therapeutic treatment. A case study is presented on the use of maggot therapy for full debridement of a necrotic wound and clearing of a meticillin-resistant Staphylococcus aureus infection. There is also discussion on how to engage healthcare workers and reduce anxieties about the use of maggots as a treatment for hard-to-heal wounds. Education and awareness are the key factors in changing healthcare workers attitudes to maggot debridement therapy.

Proteomics and Lipidomics of Black Soldier Fly (Diptera: Stratiomyidae) and Blow Fly (Diptera: Calliphoridae) Larvae

Farming insects has recently emerged as a new source of protein and lipid production. To date, research has mostly focused on food applications of insects. Focusing on nonfood potential of oil and proteins of insects, high-throughput studies of insect lipids and proteins are needed. We performed proteomics and lipidomics investigation on black soldier fly (Hermitia illucens) and blow fly (Lucilia sericata) larvae to investigate new potential and applications. We used mass spectrometry for proteomics and lipidomics analysis of control and treated larvae. Treatment was performed by incubation with a biological decomposer. We provide the list of all fatty acids with their concentration in control and treated larvae. This result showed high levels of lauric acid in black soldier fly, which could even increase after biological decomposition. Proteomics analysis showed the presence of proteins like collagen of cosmetic interest, and proteins with antimicrobial properties such as phenoloxidases and enzymatic activities, such as amylase and trypsin. Insects harbor high potential for nonfood usage as additives, antimicrobial effects, and even pharmaceuticals and cosmetics. These data open avenues for future research in pharmacological and cosmetic approaches to find new molecules of interests.

The effects of bacterial endotoxin (LPS) on cardiac function in a medicinal blow fly (Phaenicia sericata) and a fruit fly (Drosophila melanogaster)

The bacterial endotoxins, lipopolysaccharides (LPS), are known to have direct effects on mammalian heart cells; thus, LPS is likely to have some effects in other cardiac models. Drosophila melanogaster was used since it serves as a model for cardiac physiology. Larvae of blow flies (Phaenicia sericata) commonly used as therapy for debriding dead tissue, are exposed to high levels of bacterial endotoxins, but their mechanisms of LPS resistance are not entirely understood. Comparative effects of LPS on heart rate (HR) were examined for both Drosophila and blowfly larvae. Acute 10-min direct exposure of in situ heart tubes with saline containing 1, 100, and 500 μg/ml LPS from two common bacterial stains (Pseudomonas aeruginosa and Serratia marcescens) revealed a dose-dependent effect. The effects differed between the two fly models. Larval hearts of Drosophila stopped rapidly in low Ca²⁺ containing saline, but the hearts of blow flies appear unaffected for >30 min. S. marcescens increased HR initially in Drosophila followed by a reduction for low and high doses, but no change was observed in larvae of blow flies. Whereas P. aeruginosa at a high dose decreased HR in larvae of Drosophila but increased HR in larvae of blow flies. The goal of this study is to better the understanding in the direct action of LPS on HR. Knowing the acute and direct actions of LPS exposure on HR in different species of larvae may aid in understanding the underlying mechanisms in other animals during septicemia.

Spatial Distribution of Necrophagous Flies of Infraorder Muscomorpha in Iran Using Geographical Information System

Medically important flies that majority of them are classified to synanthropic flies can be mechanical vectors for some of contagious diseases to human and many animals. Also some species of their larvae are cause of myiasis in human and livestock animals. The aim of this study was to determine the geographical distribution of medically important flies in Iran using Geographical Information System (GIS). All published English and Persian documents on medically important flies of Iran from reliable medical sciences resources were gathered. A database was then designed in Excel format, including all available information regarding flies. The valid data were transferred to ArcGIS 10.3 to prepare the first spatial database of medically important flies and human myiasis foci of Iran. The Iran Medical Important Flies base includes 71 papers and three PhD/MSc theses, reporting studies conducted during 1977-2017. This database contains different available data covering their faunistic and all myiasis data reports related to flies of 102 species in nine families of medical important flies in Iran. Twenty-three out of the 31 provinces of Iran, had some reports of medically important flies. However, these flies have high species diversity, wide geographical distribution and with various ecological niches in different provinces in Iran. Besides that, there are many high-risk foci of human myiasis in a number of provinces of Iran.