Synergism between maggot excretions and antibiotics

Animal healer for refractory diseases: Myth or reality?

A vast amount of knowledge has been acquired through human activities such as farming, hunting, and fishing. Throughout history, humans have utilized living creatures for disease treatment, relying on the natural world's healing powers. The special "healers" may be able to treat patients via the power of nature. However, there was no systematic introduction or summary of these treatments. Therefore, we conducted a literature review based on PubMed, Google Scholar, Web of Science, Scopus, CNKI and WanFang DATA. Here, we defined this unique method as "animal healer" and six common kinds of animal healers were reviewed. These are fish therapy, pet therapy, worm therapy, leech therapy, maggot therapy, and bee therapy. According to the different characteristics of healers, treatment methods mainly included bite, parasitism, contact and communication. With the advantages of green and effectiveness, animal healers have great therapy potential against a variety of refractory diseases. The main purpose of this review is to draw people's attention to animal healer, promote it to become a possible clinical treatment strategy, and make further exploration in species cultivation, mechanism research, animal welfare, standard setting, safety evaluation and other aspects. In the future, animal healers will play an increasingly important role in medicine and hopefully solve more medical problems and dilemmas.

Use of biosurgery for the treatment of foot ulcers infected with therapy-resistant bacteria: a case report

Biosurgery (larval therapy) has been used for centuries. However, in recent times, this treatment has been replaced with the use of antibiotics for the treatment of wounds. Due to increasing antibiotic resistance, larval therapy is once again coming to the fore as an effective and efficient treatment. Due to the increasing ageing population, along with an increase in patients with arterial occlusive disease, diabetes and immobility, the number of patients with hard-to-heal wounds will increase. The stressors associated with wounds, such as pain, limited physical functionality, depression and social withdrawal, have a negative impact on patient quality of life. This case report documents the performance of biosurgery in a patient with multimorbidities.

Defensins of Lucilia sericata Larvae and Their Influence on Wound Repair Processes in Practical Assessment-A Study of Three Cases

Bacteria inhabiting chronic wounds form a biofilm that prolongs and slows down the healing process. Increasingly common antibiotic resistance requires clinicians to search for effective and alternative treatment methods. Defensins are the most common antimicrobial peptides capable of eradicating pathogens. Their discovery in maggot secretions allowed for a broader understanding of the healing mechanisms, and approving the use of Lucilia sericata fly larvae in the treatment of infected wounds resulted in an effective and safe procedure. The aim of the study was to present the possibility of biofilm elimination in a chronic wound by means of medical maggots (Lucilia sericata) with the example of three selected clinical cases. The observation included three women who met the inclusion criterion of having venous insufficiency ulcers with inhibited regeneration processes. Medical maggots were applied in a biobag for three days, and observation was conducted for 21 consecutive days. In 2 cases, a significant elimination of necrotic tissue from the wound bed with local granulation tissue was observed 72 h after application of a larvae colony on the wounds. In 1 case, the application of the larvae accelerated the repair process by reducing the wound area by approximately 40% at the time of observation. The formation of biofilm in a chronic wound is one of the main causes of disturbances in its effective healing. Combining procedures (scraping, antiseptic compresses, MDT, NPWT) related to wound debridement increases the effectiveness of biofilm elimination. The use of medical maggots is a safe and effective method of choice, and it enhances the processes of debridement. However, confirmed indisputable data on their effectiveness and frequency of use in the process of stimulating healing processes are still not available in the literature.

Beyond the Risk of Biofilms: An Up-and-Coming Battleground of Bacterial Life and Potential Antibiofilm Agents

Microbial pathogens and their virulence factors like biofilms are one of the major factors which influence the disease process and its outcomes. Biofilms are a complex microbial network that is produced by bacteria on any devices and/or biotic surfaces to escape harsh environmental conditions and antimicrobial effects. Due to the natural protective nature of biofilms and the associated multidrug resistance issues, researchers evaluated several natural anti-biofilm agents, including bacteriophages and their derivatives, honey, plant extracts, and surfactants for better destruction of biofilm and planktonic cells. This review discusses some of these natural agents that are being put into practice to prevent biofilm formation. In addition, we highlight bacterial biofilm formation and the mechanism of resistance to antibiotics.

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.

New Insights Into Culturable and Unculturable Bacteria Across the Life History of Medicinal Maggots Lucilia sericata (Meigen) (Diptera: Calliphoridae)

Because of the nutritional ecology of dung- and carrion-feeding, bacteria are the integral part of Lucilia sericata life cycle. Nevertheless, the disinfected larvae of the blowfly are applied to treat human chronic wounds in a biosurgery named maggot debridement therapy (MDT). To realize the effects of location/diet on the gut bacteria, to infer the role of bacteria in the blowfly ecology plus in the MDT process, and to disclose bacteria circulating horizontally in and vertically between generations, bacterial communities associated with L. sericata specimens from various sources were investigated using culture-based and culture-independent methods. In total, 265 bacteria, including 20 families, 28 genera, and 40 species, were identified in many sources of the L. sericata. Culture-dependent method identified a number of 144 bacterial isolates, including 21 species, in flies reared in an insectary; specimens were collected from the field, and third-instar larvae retrieved from chronic wounds of patients. Metagenetic approach exposed the occurrences of 121 operational taxonomic units comprising of 32 bacterial species from immature and adult stages of L. sericata. Gammaproteobacteria was distinguished as the dominant class of bacteria by both methods. Bacteria came into the life cycle of L. sericata over the foods and transovarially infected eggs. Enterococcus faecalis, Myroides phaeus, Proteus species, Providencia vermicola, and Serratia marcescens were exchanged among individuals via transstadial transmission. Factors, including diets, feeding status, identification tool, gut compartment, and life stage, governed the bacteria species. Herein, we reemphasized that L. sericata is thoroughly connected to the bacteria both in numerous gut compartments and in different life stages. Among all, transstadially transmitted bacteria are underlined, indicating the lack of antagonistic effect of the larval excretions/secretions on these resident bacteria. While the culture-dependent method generated useful data on the viable aerobic gut bacteria, metagenomic method enabled us to identify bacteria directly from the tissues without any need for cultivation and to facilitate the identification of anaerobic and unculturable bacteria. These findings are planned to pave the way for further research to determine the role of each bacterial species/strain in the insect ecology, as well as in antimicrobial, antibiofilm, anti-inflammatory, and wound healing activities.

Diabetic Foot Infections: Update on Management

PURPOSE OF REVIEW

Diabetic foot infections (DFIs) are common in patients with diabetes mellitus complicated by foot ulcers and can be classified in different categories based on their severity. In this report, we present the diagnosis and management of DFIs according to their classification.

RECENT FINDINGS

While appropriate antibiotic regiments and surgical techniques for the treatment of DFIs are well established, new technologies and techniques for example in medical imaging, wound care modalities, and supplementary therapy approaches show potentially promising results in preventing DFIs. As with every complex disease, fine tuning DFI management can be challenging as it requires careful evaluation of different parameters. It demands timely action, close collaboration of different specialties, and patient cooperation.

Pharmacological Properties of the Medical Maggot: A Novel Therapy Overview

In the last decade, maggot has been hailed as the miraculous “medicinal maggot” for its diverse properties, including antimicrobial, antibiofilm, anti-inflammatory, and wound healing activities. The fact that maggots show so many beneficial properties has increased the interest in these tiny larvae dramatically. Whilst there is relatively abundant clinical evidence to demonstrate the success of maggots as debridement agents, not so much emphasis has been placed on the basic science evidence, which was a combination of physical and biochemical actions. This review differs from those earlier works in that it is undertaken to provide an update of the latest scientific basis published on maggot, particularly active ingredients within maggot excretions/secretions (ES). Further investigations should focus on the isolation, identification, recombination, transgenosis, and mass production of the beneficial molecules within maggots.

TIME management by medicinal larvae

Wound bed preparation (WBP) is an integral part of the care programme for chronic wounds. The acronym TIME is used in the context of WBP and describes four barriers to healing in chronic wounds; namely, dead Tissue, Infection and inflammation, Moisture imbalance and a non-migrating Edge. Larval debridement therapy (LDT) stems from observations that larvae of the blowfly Lucilia sericata clean wounds of debris. Subsequent clinical studies have proven debriding efficacy, which is likely to occur as a result of enzymatically active alimentary products released by the insect. The antimicrobial, anti-inflammatory and wound healing activities of LDT have also been investigated, predominantly in a pre-clinical context. This review summarises the findings of investigations into the molecular mechanisms of LDT and places these in context with the clinical concept of WBP and TIME. It is clear from these findings that biotherapy with L. sericata conforms with TIME, through the enzymatic removal of dead tissue and its associated biofilm, coupled with the secretion of defined antimicrobial peptides. This biotherapeutic impact on the wound serves to reduce inflammation, with an associated capacity for an indirect effect on moisture imbalance. Furthermore, larval serine proteinases have the capacity to alter fibroblast behaviour in a manner conducive to the formation of granulation tissue.

Traditional Therapies for Skin Wound Healing

Significance: The regeneration of healthy and functional skin remains a huge challenge due to its multilayer structure and the presence of different cell types within the extracellular matrix in an organized way. Despite recent advances in wound care products, traditional therapies based on natural origin compounds, such as plant extracts, honey, and larvae, are interesting alternatives. These therapies offer new possibilities for the treatment of skin diseases, enhancing the access to the healthcare, and allowing overcoming some limitations associated to the modern products and therapies, such as the high costs, the long manufacturing times, and the increase in the bacterial resistance. This article gives a general overview about the recent advances in traditional therapies for skin wound healing, focusing on the therapeutic activity, action mechanisms, and clinical trials of the most commonly used natural compounds. New insights in the combination of traditional products with modern treatments and future challenges in the field are also highlighted. Recent Advances: Natural compounds have been used in skin wound care for many years due to their therapeutic activities, including anti-inflammatory, antimicrobial, and cell-stimulating properties. The clinical efficacy of these compounds has been investigated through in vitro and in vivo trials using both animal models and humans. Besides the important progress regarding the development of novel extraction methods, purification procedures, quality control assessment, and treatment protocols, the exact mechanisms of action, side effects, and safety of these compounds need further research. Critical Issues: The repair of skin lesions is one of the most complex biological processes in humans, occurring throughout an orchestrated cascade of overlapping biochemical and cellular events. To stimulate the regeneration process and prevent the wound to fail the healing, traditional therapies and natural products have been used with promising results. Although these products are in general less expensive than the modern treatments, they can be sensitive to the geographic location and season, and exhibit batch-to-batch variation, which can lead to unexpected allergic reactions, side effects, and contradictory clinical results. Future Directions: The scientific evidence for the use of traditional therapies in wound healing indicates beneficial effects in the treatment of different lesions. However, specific challenges remain unsolved. To extend the efficacy and the usage of natural substances in wound care, multidisciplinary efforts are necessary to prove the safety of these products, investigate their side effects, and develop standard controlled trials. The development of good manufacturing practices and regulatory legislation also assume a pivotal role in order to improve the use of traditional therapies by the clinicians and to promote their integration into the national health system. Current trends move to the development of innovative wound care treatments, combining the use of traditional healing agents and modern products/practices, such as nanofibers containing silver nanoparticles, Aloe vera loaded into alginate hydrogels, propolis into dressing films, and hydrogel sheets containing honey.

Maggot debridement therapy: a systematic review

Maggot debridement therapy is used extensively in the UK in both community and hospital situations, but remains a potentially under-used modality in many wound care markets. It promotes wound healing by performing three key processes: debridement, disinfection and growth-promoting activity. It can be used for the debridement of non-healing necrotic skin and soft tissue wounds, including pressure ulcers, venous stasis ulcers, neuropathic foot ulcers and non-healing traumatic of post-surgical wounds. With the increase in chronic diabetic foot wounds, maggot debridement therapy is a promising tool for health professionals dealing with difficult wounds. This article presents an overview of the research evidence surrounding maggot debridement therapy that serves as a guide to health professionals who may be users of this form of treatment now and in the future.

Polymicrobial wound infections: pathophysiology and current therapeutic approaches

Acute and chronic wounds represent a very common health problem in the entire world. The dermal wounds are colonized by aerobic and anaerobic bacterial and fungal strains, most of them belonging to the resident microbiota of the surrounding skin, oral cavity and gut, or from the external environment, forming polymicrobial communities called biofilms, which are prevalent especially in chronic wounds. A better understanding of the precise mechanisms by which microbial biofilms delay repair processes together with optimizing methods for biofilm detection and prevention may enhance opportunities for chronic wounds healing. The purpose of this minireview is to assess the role of polymicrobial biofilms in the occurrence and evolution of wound infections, as well as the current and future preventive and therapeutic strategies used for the management of polymicrobial wound infections.

A randomized controlled trial of larval therapy for the debridement of leg ulcers: results of a multicenter, randomized, controlled, open, observer blind, parallel group study

It has been known for centuries that the application of larvae is useful to heal certain wounds by facilitating debridement of necrotic tissue,(1) yet the efficacy of larval therapy continues to be debatable. This study compared the clinical effectiveness of a larval therapy dressing (BioFOAM) with a standard debridement technique (Purilon gel; hydrogel) in terms of time to debridement of venous (VLU) or mixed arterial/venous (MLU) leg ulcers. Data analyses were conducted on 88 subjects. Sixty-four subjects completed the full study. Of these, 31 of the 32 (96.9%) patients who completed treatment in the larvae arm debrided fully, compared with 11 of the 32 (34.4%) patients who completed the hydrogel arm. In addition, 42 (48%) ulcers fully debrided within the 21-day intervention phase, 31 (67.4%) from the larvae arm (n = 46), and 11 (26.2%) from the hydrogel arm (n = 42), which was statistically significant (p = 0.001) in support of larvae. A statistically significant difference was also observed between treatment arms with regard to numbers of dressing changes during the intervention phase of the study (p < 0.001) in that subjects in the larvae arm required significantly fewer dressing changes(mean = 2.83) than those in the hydrogel arm (mean = 5.40). There were no statistically significant differences in the clinical condition of the wound bed and surrounding skin by intervention. Subjects in the larvae arm experienced more ulcer-related pain or discomfort than subjects in the hydrogel arm (p < 0.001). This study provided good evidence to show that larval therapy, in the form of a BioFOAM dressing, debrided VLU and MLU considerably more quickly than a hydrogel, although the possibility of resloughing should be closely monitored.

Excretions/secretions from bacteria-pretreated maggot are more effective against Pseudomonas aeruginosa biofilms

BACKGROUND

Sterile larvae--maggots of the green bottle blowfly Lucilia sericata are employed as a treatment tool for various types of chronic wounds. Previous studies reported that excretions/secretions (ES) of the sterile larvae could prevent and remove the biofilms of various species of bacteria. In the present study we assessed the effect of ES from the larvae pretreated with Pseudomonas aeruginosa on the bacteria biofilms.

METHODS AND FINDINGS

We investigated the effects of ES from the maggot pretreated with P. aeruginosa on the biofilms using microtitre plate assays and on bactericidal effect using the colony-forming unit (CFU) assay. The results showed that only 30 µg of the ES from the pretreated maggots could prevent and degrade the biofilm of P. aeruginosa. However, the CFU count of P. aeruginosa was not decrease when compared to the ES from non pretreated maggots in this study condition. It is suggested that the ES from the pretreated maggot was more effective against biofilm of P. aeruginosa than sterile maggot ES.

CONCLUSIONS

Our results showed that the maggot ES, especially the bacteria-pretreated larva ES may provide a new insight into the treatment tool of the bacterial biofilms.

Biocompatibility of antimicrobials to maggot debridement therapy: medical maggots Lucilia sericata (Diptera: Calliphoridae) exhibit tolerance to clinical maximum doses of antimicrobials

The larvae of calliphorid flies are used to debride wounds of patients with severe tissue destruction, often concurrently with antimicrobials. The current study evaluates the effects of ceftazidime, tobramycin, amikacin, gentamicin, polymyxin B, doxycycline, paromomycin, amphotericin B, sodium stibogluconate, and miltefosine at 1, 10, and 100 x the Maximum Clinical Concentration (mg/kg/d) in raw liver assays. Effects on larvae were small and depended on dose and antimicrobial formulation, with hours in assay (24 or 48 h) having a significant effect on larval survival. Sodium stibgluconate had the strongest effect on maggot survival (80.0% at 48 h). These results suggest that the antimicrobials tested here may be used simultaneously with maggot debridement therapy, and may actually increase the effectiveness of maggot debridement therapy in certain applications where >1 x Maximum Clinical Concentration is indicated, such as topical creams for cutaneous leishmaniasis.

Polymicrobial interactions: impact on pathogenesis and human disease

Microorganisms coexist in a complex milieu of bacteria, fungi, archaea, and viruses on or within the human body, often as multifaceted polymicrobial biofilm communities at mucosal sites and on abiotic surfaces. Only recently have we begun to appreciate the complicated biofilm phenotype during infection; moreover, even less is known about the interactions that occur between microorganisms during polymicrobial growth and their implications in human disease. Therefore, this review focuses on polymicrobial biofilm-mediated infections and examines the contribution of bacterial-bacterial, bacterial-fungal, and bacterial-viral interactions during human infection and potential strategies for protection against such diseases.