Maggots may be the answer to antibiotic-resistant infections, say doctors.

They have found that maggots have been able to clear up methcillin resistant Staphylococcus aureus (MRSA) - the bug which has defeated most other drugs and has become a major problem in many of the country's hospitals.

Researchers at the Princess of Wales Hospital in Bridgend, Wales, say they have found that swabs of MRSA-infected wounds which have been treated with maggots have come back negative.

It is not fully understood how the maggots work.

But there are three main theories - they either produce anti-bacterial agents, suck up bacteria or change the acidity of an infection.

Maggot history

Maggots were widely used for medicinal peurposes at the beginning of the century.

But with the advent of antibiotics in the 1940s, their use died out.

Now, the rise of antibiotic-resistant infections is causing a renewed surge in interest.

They are mostly used to treat ulcers, pressure sores and infections caused by diabetes.

The Princess of Wales Hospital is the sole breeder of sterile greenbottle fly larvae in the UK.

They also export the larvae to other countries in Europe.

Greenbottle larvae are used because they are known only to digest dead tissue and do not burrow down into live flesh.

Other larvae, for example, the screw worm, do eat living tissue.

Last resort

Doctors at the hospital want the NHS to use maggot therapy more.

In a letter to the British Medical Journal, they say doctors now use maggots as a last resort.

"We suggest that the earlier application of maggots should be consider to clean up problems or infected wounds at an earlier stage, which would in many cases obviate the need for topical or systemic antimicrobial treatment."

Andrea Andrews, manager of the hospital's biosurgical research unit, told BBC News Online: "Patients are okay about having maggots applied to their wounds when the process has been explained to them. It is the doctors who are the problem.

"Patients have often been suffering for years and have tried all conventional treatments. They just want to get healed.

"Doctors seem to think maggots are a step backwards. Or maybe they just don't like wriggly maggots."

The maggots are used when they are only three days old and around two millimetres long.

They are applied to the wound, sealed in with a bandage and left to feed.

They churn out enzymes that break up the dead tissue and liquefies it.

The maggots them suck it back up, cleaning up the infection as they go.

The researchers are holding a series of study days around the country to spread the word about maggots.