Bacteria toxic to wound-treating maggots

Feb 04, 2010

Bacteria that infect chronic wounds can be deadly to maggot 'biosurgeons' used to treat the lesions, show researchers writing in the journal Microbiology. The findings could lead to more effective treatment of wounds and the development of novel antibiotics.

Scientists from the Copenhagen Centre, Statens Serum Institut and the University of Copenhagen in Denmark showed that maggots applied to simulated wounds heavily infected with the aeruginosa, were unable to treat the wound and were left dead after 20 hours.

, such as , affect 1% of the Western population and are painful and difficult to treat. Use of maggots to disinfect wounds is an ancient practice that regained popularity in the early 1990s. Maggot Debridement Therapy (MDT) is now a standard procedure at wound care centres all over the world, in which sterile larvae from the green bottle fly Lucilia sericata are applied to the wound either directly or contained within a sealed nylon bag. The maggots gently ingest necrotic (dead) tissue and kill ingested bacteria in the gut. In addition, the maggots secrete antimicrobial compounds into the wound, help reduce inflammation and promote wound healing. The actual biological mechanisms responsible for the process are still largely a mystery.

P. aeruginosa is an opportunistic bacterium responsible for many hospital-acquired infections. It is often associated with chronic wounds in which the bacteria clump together to form biofilms. By effectively talking to each other via a well-studied communication system called quorum sensing (QS), bacteria in biofilms are known to be more successful at avoiding destruction by the host immune system as well as antibiotics.

Dr Anders Schou Andersen, who led the research, explained that QS was also the key to P. aeruginosa's toxicity to maggots. "When we blocked the QS signalling pathways in the bacteria, the maggots were much better at surviving and potentially cleansing the wounds. Signalling between bacteria growing in biofilms is known to lead to the production of lethal toxins, without which the bacteria are more vulnerable to eradication."

Dr Andersen believes the research could benefit patients with persistent wounds. "MDT is generally very effective. It has been said that in a few cases MDT had failed, leaving the maggots dead in the lesion. We now think that this was probably due to the presence of P. aeruginosa in the wound," he said. "If we can find the specific bacterial mechanism that kills the maggots, we could target this when developing new treatments. For example, wounds infected with P. aeruginosa could be treated with an agent that interrupts bacterial signalling to ensure the success of maggot therapy and thereby wound healing."

Explore further: Life's extremists may be an untapped source of antibacterial drugs

More information: A. S. Andersen, B. Jorgensen, T. Bjarnsholt, H. Johansen, T. Karlsmark, M. Givskov and K. A. Krogfelt ‘Quorum-sensing-regulated virulence factors in Pseudomonas aeruginosa are toxic to Lucilia sericata maggots’ Microbiology; 156: 400 - 407.

Provided by Society for General Microbiology

5 /5 (5 votes)

Related Stories

Maggots make a comeback in Mexico

Mar 26, 2007

Doctors in Mexico are beginning to use a centuries-old and cost effective treatment for the healing of wounds -- maggot therapy.

Artificial skin system can heal wounds

Dec 20, 2007

A new study in Artificial Organs tested the effects of a wound dressing created with hair follicular cells. The findings reveal that skin substitutes using living hair cells can increase wound healing.

Washing away painful wounds

Aug 26, 2009

More than six million people in the U.S. suffer from persistent wounds -- open sores that never seem to heal or, once apparently healed, return with a vengeance. The bedridden elderly and infirm are prone ...

Recommended for you

Cohesin molecule safeguards cell division

Nov 21, 2014

The cohesin molecule ensures the proper distribution of DNA during cell division. Scientists at the Research Institute of Molecular Pathology (IMP) in Vienna can now prove the concept of its carabiner-like ...

Nail stem cells prove more versatile than press ons

Nov 21, 2014

There are plenty of body parts that don't grow back when you lose them. Nails are an exception, and a new study published in the Proceedings of the National Academy of Sciences (PNAS) reveals some of the r ...

Scientists develop 3-D model of regulator protein bax

Nov 21, 2014

Scientists at Freie Universität Berlin, the University of Tubingen, and the Swiss Federal Institute of Technology in Zurich (ETH) provide a new 3D model of the protein Bax, a key regulator of cell death. When active, Bax ...

Researchers unwind the mysteries of the cellular clock

Nov 20, 2014

Human existence is basically circadian. Most of us wake in the morning, sleep in the evening, and eat in between. Body temperature, metabolism, and hormone levels all fluctuate throughout the day, and it ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.