A North-East scientist has made a breakthrough which has the potential to save thousands of lives. Health Editor Barry Nelson talks to Dr Gary Black.

IT is one of the most feared diseases which can "eat" flesh from a human arm or leg. Necrotizing fasciitis, sometimes described as the "flesh-eating bug", is a very rare and dangerous condition which needs rapid treatment with powerful antibiotics.

It is caused by the streptococcus aureus bacterium (Strep A), a common bug which can be detected in around 40 per cent of people.

Normally, this microscopic organism lives harmlessly in our nasal cavities, armpit and skin, and is responsible for nothing worse than a sore throat.

But for some unknown reason, usually when an individual is injured or very ill, Strep A can turn into a virulent, invasive and potentially life-threatening infection.

The same, usually innocuous, bacterium can also be responsible for blood poisoning (medical name septicaemia) and toxic shock syndrome. Worryingly, all of these potentially fatal diseases have been on the increase in the last decade.

While most people in Britain and the rest of the developed world who contract any of these conditions can usually be treated successfully, there is growing evidence that the bacterium is becoming resistant to common antibiotics.

And in the wider world, in developing countries where medicines are either unaffordable or non-existent, these diseases kill hundreds of thousands of people every year. Some estimates suggest that a million lives a year are claimed by virulent diseases caused by streptococcus bacterium.

That's why the work of a County Durham scientist is attracting worldwide attention.

Dr Gary Black, as part of a team from Northumbria University's School of Applied Sciences, has made a highly significant discovery. By using cloning techniques which are similar to the approach used in DNA testing, the team was able to isolate one of the main enzymes involved in the disease, known as a hyaluronidase, or HylP1.

By studying this enzyme, which plays a vital role in turning the bug into a potential killer, Dr Black's team believe they might be able to figure out new ways of combating and containing diseases like toxic shock syndrome, septicaemia and flesh-eating necrotizing fasciitis.

The scientist hopes that major pharmaceutical companies will be interested in funding further research to turn pure science into a practical cure.

Although Northumbria University is predominantly a teaching institution and is not renowned for scientific research, the significance of Dr Black's discovery is underlined by the publication of his results in the Proceedings of the National Academy of Sciences of the United States of America (PNAS), one of the world's most cited multidisciplinary scientific serials. Set up in 1914, it publishes cutting-edge research and spans biological, physical and social sciences.

Dr Black, a home-grown North-East scientist who was born in Consett and grew up in Stanley, is delighted that an interest in this particular bacterium has paid off in such a spectacular fashion.

"We have worked out the shape of this enzyme which should allow us to try to figure out how it works," says Dr Black, who started this pioneering research project in conjunction with York University when he joined Northumbria University five years ago.

"The enzyme is important because it is the factor which allows the organism to spread so rapidly. It facilitates the invasion of tissue by degrading the protective barrier. "The shape of this enzyme is quite novel. Most enzymes are globular but this is a long thin fibre, a double-helix like DNA."

The Northumbria University team now hopes they will be able to attract substantial funding to enable them to pursue their work.

"What we need to do is work out which part of the enzyme is important in the process of spreading the disease. It works by cutting and then binding. If we can disable the enzyme in some way it could stop the process," says Dr Black, who now lives in Durham City.

"We still think there is a lot of scientific work to be done. We need at least another three to four years," he adds.

One vital element which remains tantalisingly out of reach is to try to work out what turns a normally harmless organism into a potential killer. "There is clearly a trigger which starts this process but nobody knows what this is at this stage," he says.

What is certain is that these relatively rare conditions are more common in young children or older people.

Dr Black explains: "It is the young and the old who are more vulnerable to these diseases because they have weaker immune systems."

Developing a cure for conditions like toxic shock syndrome will involve major research, probably backed by a pharmaceutical company.

It is too early to speculate on what form a cure might take. But as conditions like toxic shock, septicaemia and necrotizing fasciitis usually depend on cuts or burns to take hold in the body it seems reasonable that some form of protective cream might be developed.

While the Northumbria University scientist is elated at the international attention generated by his scientific paper he is realistic enough to know that his work can only go so far and it is only a small piece in a larger jigsaw puzzle.

"The issue of what triggers something like toxic shock syndrome is big science which will probably need to be done elsewhere," he says.