Maggot Therapy vs. MRSA –The Antimicrobial Bio-surgeons that Know Best
by Jade Rogers
The battle between infectious bacteria and the antibiotic drugs used to treat them is not a new one, and is far from over. The World Health Organisation reports that many infectious diseases of today are at high risk of becoming uncontrollable due to antibiotic resistance. Approximately 440,000 new cases of multi-drug resistant tuberculosis emerge each year and cause more than 150,000 deaths worldwide. Patients with compromised immune systems are at most risk from such infections – the very old, severely ill, those on chemotherapy or immune-suppressant medication. Despite the revolutionary contribution that antibiotics have made to our healthcare this century, the overuse and misuse of these drugs has drastically reduced their efficacy. With microbes evolving faster than our corporate drug antibiotic resistance research, we are forced to seek other antimicrobial methods, including more natural ones from our past.
Maggot Debridement Therapy (MDT) is a treatment used to aid the healing process of chronic wounds by introducing medicinal (sterile) larvae of specific necrotic tissue-eating blowflies (usually Lucilia sericata – common blowfly or green bottle) to the wound and securing with special dressings. Over a couple of days, the larvae then eat away the necrotic tissue, stimulate new tissue growth and disinfect the area.
It has long been observed throughout history that a maggot infested wound provides a successful healing outcome, especially before medicine as we know it today. This method is thought to have been used by Aboriginal tribes in Australia and there are many accounts from military surgeons who witnessed colonisation of soldier’s wounds with maggots on the battlefield. Dr. William Baer, an orthopedic surgeon serving in World War I, noted that wounded soldiers who had been left and acquired maggots in their wounds had much better outcomes than some of those who were treated conventionally, or received no treatment at all. In late 1920, Baer conducted a study to test the efficacy of maggot therapy, proving it a success and publishing his work. Since then, maggot therapy became a more common treatment for deep and infected wounds until the mid-1940’s when surgical methods had advanced and penicillin became widely available, rendering this traditional method out of date.
After just a few years of penicillin’s mass distribution, resistant strains of bacteria were beginning to emerge. Methicillin was one of the first of many antibiotic drugs to succumb to the constant evolution of the bacterium Staphylococcus aureus, which developed genetic resistance and via continuous mutation and selection became today’s most notorious ‘superbug’, MRSA (Methicillin Resistant Staphylococcus aureus). Bacteria are among the most rapidly evolving organisms due to the extremely short reproduction time of 20 minutes (under optimum growth) and their ability to transfer resistance genes horizontally among a single generation. Therefore it doesn’t take long for bacteria to become ‘wise’ to the medicines that were once able to control them, becoming a constantly moving target for drug developers. S. aureus has continued to evolve resistance to further types of antibiotics, such as vancomycin and erythromycin. Disturbingly, MRSA isn’t the only superbug, with resistance displayed in Streptococcus pneumonia, Streptococcus pyogenes members of the Enterobacteriaceae and Pseudomonas families as well as Escherichia coli among many others.
The Last Resort
The chronic wounds in some patients fail to respond to antibiotics and surgical methods, leaving amputation of the affected area as the only option. However, patients that have turned to MDT after years of failed conventional therapies have in many cases reported success. Although MDT may not appeal to some, for others it has been the final solution to an ongoing battle. A natural, traditional, low cost, speedy and successful remedy versus the loss of a limb or in extreme cases, a life -‘creepy crawlies’ roaming around on your skin is a small price to pay. Only since the rise of multi-resistant strains of infectious bacteria has the science behind maggot therapy begun to be properly researched. Despite having used this treatment for centuries, only recently has the extent of this simple remedy’s complexity been understood.
How it Works
Tiny medicinal larvae are simply applied to the wound and secured with a specialised dressing, left to feed for 1-2 days and then removed. Depending on the wound’s severity, this treatment may be repeated several times over a period. During the time in which they are sealed in the wound, the larvae begin treatment via consumption of the necrotic tissue (debridement), much like a surgeon would using sharp instruments. The larvae are only able to remove necrotic and not live tissue due to the specificity of the digestive enzymes they produce . It is this removal of the dead tissue which kick-starts the healing process by actively promoting new tissue formation. The debridement process alters the interaction between fibroblasts and the extracellular matrix, which are both important components of the healing process.
The most surprising feature that makes MDT so successful and useful where conventional antibiotics fail is the potent antimicrobial properties of the maggot’s slime, more properly known as excretion/secretion (ES). It appears to inhibit biofilm formation (structured bacterial growth), and disrupt that already existing on wounds infected with Staphylococcus species, by up to 92% in some cases. Further studies have shown that blowfly ES in vitro is potent enough to exhibit antimicrobial activity against MRSA.
My own research (under supervision of A. Bexfield and N. A. Ratcliffe, Swansea University, UK, 2008) indicated that the antimicrobial effect of ES against E. coli and S. aureus was significantly increased by pre-exposure of the larvae to each pathogen, suggesting that the immune system of the larva is able to alter the efficacy of the ES. This approach utilises a dynamic biological mechanism to come up with novel antibiotic chemicals, essentially recruiting the creative process of evolution onto our side in the battle to control infection. Further research on this approach may prove highly beneficial to our healthy futures, so long as you can deal with the wriggling beneath your bandages!
Warning – please do not self medicate with maggots! This treatment must be conducted by medical professionals under controlled conditions using sterile larvae.
About the author: Jade Rogers studied Biology at Swansea University, Wales, specialising in medical microbiology. She has since worked as a microbiologist, biology teacher and is currently an environment management officer while volunteering at the local medical emergency department. Jade takes an interest in natural healthcare, nutrition and lifestyle, and hopes to begin a medical degree to pursue her passion for the subject.
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