Breakthrough 'may contain superbug'

The bug can cause particular problems in intensive care

Scientists have discovered the genetic characteristic that turns a bacterium into a serious health threat for hospitals.

They say hospital patients should be screened to discover who is carrying the form of the bug that can cause a disease epidemic.

Isolating these patients could be the only effective way to prevent infection from running rife.

The bacterium, Enterococcus faecium can cause serious illness among vulnerable hospital patients whose immune systems are weakened.

Those most at risk include transplant patients and those receiving intensive care.

This is a powerful diagnostic tool

Dr Rob Willems, National Institute of Public Health

The bug poses an ever-increasing threat because it is becoming increasingly resistant to all commercially available antibiotics.

It is already a serious problem in the US, and although outbreaks in Europe are relatively rare, they are believed to be on the increase.

Three instances of hospital-based infections have recently been reported in the Netherlands.

Rob Willems and colleagues from the National Institute of Public Health, Bilthoven, Netherlands, did a genetic analysis of the bug.

Virulent form

They discovered that one particular form was responsible for hospital outbreaks in the US, Europe and Australia.

This form carries a variant of a gene called the ESP gene which makes it more virulent than other strains and which allows the bacterium to spread more easily in hospitals.

Because in many cases all forms of treatment are ineffective, patients infected by the bug remain infectious for prolonged periods of time.

This enables the bug to spread rapidly within a hospital, and once it has taken hold it is almost impossible to control its further spread.

However, Dr Willems believes that it should now be possible to prevent the bug from spreading by isolating patients who are carrying the epidemic form.

He told BBC News Online: "This is a powerful diagnostic tool which should allow hospitals to take action to prevent the spread of infection."

It is estimated that 1% to 2% of enterococcus faecium bacteria found in Europe are resistant to the most powerful antibiotic currently available, vancomycin.

Dr Willems said the best way to ensure that the problem did not become worse was to restrict use of the antibiotic to minimise the opportunity for the bug to develop resistance.

A spokesperson for the Public Health Laboratory Service said: "The research is scientifically interesting and may help to control of future hospital outbreaks."

However, he added that screening required specialist skills and equipment likely to be available only in research laboratories in the UK.

He said newly licensed antibiotics had proved effective at treating vancomyin-resistant forms of the bug.

The research is published in The Lancet medical journal.