A VIRTUALLY untreatable new superbug has been found in Scotland for the first time after causing death and panic in hospitals in the US and England.

Eleven patients have tested positive for the presence of multi-antibiotic-resistant Acinetobacter, which - unlike MRSA - can only be treated with one medicine.

Health chiefs believe the new superbug is now present throughout Scotland and it is only a matter of time before it mutates into a particularly deadly form which does not respond to any known antibiotic.

That form of Acinetobacter has wreaked havoc in the health service south of the Border over the past two years, killing 39 people at one London hospital alone.

Scotland appears to be fighting a losing battle against hospital-acquired infection. Scotland on Sunday recently revealed that cases of MRSA had soared despite a multi-million pound campaign to cut cases of infection.

The revelation that an even more dangerous superbug has been discovered in Scotland will add to the pressure on ministers to take action to reduce the toll of 1,000 Scots infected annually by MRSA alone.

Tests carried out by NHS Tayside found that 11 patients were carrying Acinetobacter over the past year, although none were infected by it. All were immediately isolated.

The bacteria can only be treated with "last-resort" antibiotics called carbapenems. Doctors are keen to use these as sparingly as possible because over-use allows the bacteria to develop resistance.

Microbiologist Dr Ian Gould, from Aberdeen University, said it was likely the bacteria would be present in other Scottish hospitals.

And he called for health boards to step up their surveillance of the bug, warning that it was only a matter of time before carbapenem-resistant Acinetobacter reached Scotland.

He said: "Unfortunately these bacteria will grow increasingly resistant to antibiotics as they evolve. What is causing major concern is the strains that are resistant to carbapenems. Acinetobacter are particularly good at producing enzymes that destroy these antibiotics.

"One would expect them to percolate north of the Border from transfer patients who move between hospitals. Sooner or later carbapenems-resistant Acinetobacter is going to arrive here."

Acinetobacter is commonly found in water and soil but normally causes no problems unless it infects critically ill, elderly or vulnerable patients.

Throughout Scotland, during the first three months of 2006, there were 20 cases of patients being infected with "treatable" strains of Acinetobacter.

Doctors in England are now being forced to resort to outdated antibiotics that were abandoned 50 years ago for being highly toxic to patients in order to defeat the deadliest versions of the bug. At St Mary's Hospital in Paddington, West London, 39 people died after catching Acinetobacter.

The Health Protection Agency in England has issued guidelines on tackling the bug and NHS Trusts have been ordered to monitor drug-resistant strains of the bacterium.

But in Scotland health boards only monitor Acinetobacter on a voluntary basis. The discovery of multi-resistant strains north of the Border has now led to calls for increased surveillance. Gould said: "I think there are so many other pressures that in the current state of alert, it is hard to convince health boards to screen for that particular bacteria as it is not particularly easy to do."

Professor Curtis Gemmell, a microbiologist at Glasgow University, said it was impossible to determine if the bacteria was spreading unless it was monitored more closely.

He said: "Without knowing if this bacteria has become established on hospital wards it could be an isolated case or something more serious that will spread from hospital to hospital.

"At the moment we have not had any infections in patients. Only when that happens do we need to start worrying."

Shona Robison, SNP shadow health minister, said: "The threat this bacteria poses is very concerning and highlights the need for hygiene and cleanliness to be the best it possibly can be."

A spokeswoman for the Scottish Executive said it was attempting to standardise diagnosis and detection of antibiotic resistance for a range of organisms.

She added: "This infection does not present a significant problem in Scotland but we remain vigilant in tackling all sorts of healthcare-associated infections."