Coating artificial hips, heart valves and other medical implants with a type of seaweed could prevent patients from contracting life-threatening infections, research suggests.

A study carried out by scientists in Australia has found that chemicals in marine algae can fight the bacteria that cause many of the infections associated with surgery, including the super bug MRSA.

Some of these infections are caused by bacteria, which normally lives harmlessly on skin, attaching themselves to implants during operations.

People who have surgery have in effect a wound opened up and that does give bacteria the opportunity to gain a foothold

PHLS spokesman

These bacteria can often bond together inside the body and cause infection. Neither the body's immune system nor antibiotics can kill them. In many cases, patients have to undergo surgery again to rectify the problem.

However, scientists at the Cooperative Research Centre for Eye Research and Technology in Sydney say their discovery could provide a solution.

Active agent

Jasjit Baveja and colleagues have found that chemicals called furanones reduced the numbers of a bacterium called Staphylococcus epidermidis coating plastic plates by 90% in laboratory experiments.

The agents were also found to inhibit the growth of bugs such as Staphylococcus aureus or MRSA, which grows on metal implants and is often resistant to antibiotics.

Furanones have previously been identified as the agents that keep a red alga called Delisea pulchra free of bacteria and other marine organisms.

The researchers tested their findings in sheep. They found that catheters which had been coated with furanone had 85% less bacteria after 12 weeks than would normally be expected.

Those catheters that had not been coated with the agent were covered in bacteria.

The chemical does not kill the bacteria but instead prevents them from coming together, which in turn prevents infection.

According to New Scientist magazine, the Australian researchers are now planning to examine whether the agents are safe to use in humans. If successful, human trials could begin within five years.

Infection surveillance

The Public Health Laboratory Service introduced mandatory reporting of Staphylococcus aureus infection in 2001 as part of efforts to tackle the problem.

The latest figures available show there were more than 12,000 reports of S. aureus infection in hospitals in England and Wales in 2001.

A recent report by the PHLS suggested that 3% of patients who undergo hip replacement surgery in hospitals in England develop these bacterial infections. The rate for knee replacement surgery was 2%.

Hospitals have introduced infection control measures to try to reduce this figure.

A spokesman for the PHLS said: "Infections following surgery are well established. People who have surgery have in effect a wound opened up and that does give bacteria the opportunity to gain a foothold. That is why good infection control is so important."