Touching Lives - October 2008
Maggots could hold key to treating MRSA
Sick and hospitalised patients commonly become infected with superbugs such as MRSA. As the number of cases has risen rapidly, so has the number of deaths — between 2002 and 2006, 6,201 deaths in England and Wales involved MRSA and 15,683 deaths involved C. difficile — making the need for an effective treatment all the more urgent.
The new antibiotic, named Seraticin™, is derived from the maggot secretions of the common green bottle fly (Lucilia sericata) and was discovered by Professor Ratcliffe and his colleagues at Swansea University. They received £160,546 in Action Medical Research funding in 2005 to carry out this ground-breaking work. During the course of the grant, which was supported by The Rosetrees Trust and one of our Action Partners, the team tested Seraticin™ on a number of bacteria and found it to be effective on C. difficile, E coli and no fewer than 12 strains of MRSA. They also purified the antibiotic to carry out a detailed study of its structure, and the mechanism by which it prevents infection.
Dangers of MRSA
MRSA does not usually cause infection in healthy people, and while infection outside hospital is possible, hospital patients are more vulnerable because they are likely to have an entry point for the bacteria to get into the body, such as a surgical wound, catheter or intravenous drip. Once inside, MRSA can cause infection in almost any part of the body including the joints, braintissue, bloodstream and bone marrow. This virulent infection, resistant to many conventional antibiotic treatments, also has huge financial implications, costing the NHS an estimated £1 billion per year.
Modernising age-old science
Using live maggots to clean infected wounds is an age-old method of tackling infection, and they work with amazing speed. It is not uncommon for someone to suffer from chronic infected wounds for 18 months, despite all sorts of conventional treatment, but when maggots are applied to the same wound, infection can often begin to clear in just a few days. They have even been known to save people from amputation. These medicinal maggots certainly captured the imagination of the media when Professor Ratcliffe and his colleagues Professor Russell Newton, Dr Yamni Nigam, Dr Stephen Thomas, Dr Alyson Bexfield and Dr Elizabeth Bond worked closely with Action Medical Research to release the details of their discovery in August. You may have seen it reported on ITN, read about it in the Sun, Daily Mirror or Daily Mail, or on one of the many websites that covered the story online. It was even reported as far afield as America, Iran and New Zealand! Professor Ratcliffe comments, “It has been a huge team effort to get to this level and I am delighted with our progress so far.”
The team have since been awarded a further Action Medical Research grant, worth £190,557, bringing the charity’s investment in this research to over £350,000. This funding will enable the team to complete their study of the chemical make-up of the antibiotic, so that it can be made synthetically and tested in the laboratory. Professor Ratcliffe continues, “^There is more to do if we are to realise the maximum benefits from this discovery^. It takes approximately 20 mugs of maggots to yield just one drop of purified Seraticin™ at present. Thus, the next stage will be to confirm its exact identity using mass spectrometry and nuclear magnetic resonance analyses in order for us to produce this chemically on a larger scale. ” This new antibiotic can then be tested on human cells, and eventually in clinical trials in order to determine its medical effectiveness and properties as a novel antibiotic. The ultimate aim is to develop it into an injection, pill or ointment. Action Medical Research’s Dr Yolande Harley says, “The discovery of a potential new antibiotic is an exciting advance. It could mean a novel treatment for people with chronic wounds that are infected with MRSA or other superbugs. By developing the pure antibiotic into a formula, such as a cream, it could reduce the contact patients need to have with live maggots to heal wounds. It could also offer a potential treatment, through an injection or pill, for internal infections like C. difficile.”
Dr Alun Morgan of ZooBiotic Ltd, the Bridgend-based company that supplied the maggots for the project, says, “Maggots are great little multi-taskers. They produce enzymes that clean wounds, they make a wound more alkaline which may slow bacterial growth and they produce a range of antibacterial chemicals that stop the bacteria growing.”