MUTANT and highly toxic strains of the killer superbug MRSA could pose a “serious threat”, even to the healthy, experts warn.
Scientists investigating the new infections, which have already migrated here from the United States, say they are far more powerful than any seen before in this country.
The potentially deadly strains are easily passed between people outside of hospitals and are on the increase in Britain.
One version of the killer bug – called USA300 – is passed easily through skin contact and can lead to a flesh-eating form of pneumonia.
It is resistant to even the most powerful antibiotics and could cause widespread infection and large numbers of deaths if it spreads suddenly.
USA300 has already killed thousands of people in America and is the highest single cause of death there from infectious disease.
It can cause large boils on the skin and lead to fatal blood poisoning or a form of pneumonia that can eat away at lung tissue.
Experts say that as well as beating the best treatments which are currently available, the new form can maintain a higher level of toxicity.
This makes it far more infectious than the strains we see in Britain in many hospitals at the moment and can even infect healthy people.
That means it would be capable of infecting people out in the wider community with no way of bringing it under control.
The new warning comes after the World Health Organisation warned last year that the failure to tackle superbugs could lead to a “nightmare scenario” in which the world has no new drugs to treat patients hit by a resistant strain. Now an MRSA expert from the University of Bath has warned that this highly toxic strain of the disease poses a serious threat to people in Britain.
Typically, people in this country become infected with MRSA in hospital when they are already sick and have a reduced ability to fight the bacteria.
Hospital-acquired MRSA has been causing problems for decades but there has been some success in reducing infections in recent years.
However Dr Ruth Massey, from the university’s department of biology and biochemistry, has now expressed concern about the emergence of a new MRSA bacterium over the past few years in the US capable of infecting healthy people.
She said extra vigilance was required around what is known as PVL-positive community acquired MRSA strains, including USA300.
In a new research paper published in the Journal of Infectious Diseases, Dr Massey and colleagues analyse the way community-acquired MRSAs are able to adapt and fine-tune themselves to spread outside hospitals.
MRSA bacteria in hospitals have not been able to migrate into the community in the same way.
Justine Rudkin, a PhD student working on the project, said: “The community-acquired bacteria have evolved further and are able to maintain a higher level of toxicity while also resisting treatment from antibiotics, making it a much larger problem.
“While we are constantly learning more about MRSA, there is a serious threat posed by this newer strain of bacteria capable of causing disease and even death in perfectly healthy people.
“We need to respond seriously to this threat as it reaches Britain.”
A spokeswoman for the Health Protection Agency said: “The HPA are carrying out active surveillance of this type of bacteria and advise healthcare professionals on correct infection control procedures to reduce the likelihood of spread.”