A cure may be on the way for some of the world's most deadly diseases, it was disclosed today.

Toxic shock syndrome, septicaemia and the flesh-eating disease necrotizing faciitis, which kill thousands of people, could be consigned to medical textbooks following a medical breakthrough.

These antibiotic-resistant diseases are caused by the streptococcus bacterium, which has increased significantly over the past 10 years.

Until now, scientists have not understood what turns this ordinary bacterium - which is best known as the cause of sore throats - into something that can prove fatal.

Researchers at Northumbria University in Newcastle now believe they have found a way genetically of curing the streptococcus bacterium.

Dr Gary Black, and a team from the university's school of applied sciences, has isolated one of the main enzymes implicated in disease - known as a hyaluronidase, HylP1.

In a process similar to the one used in DNA testing, pure enzymes were produced in large quantities, by isolating the gene and then inserting it into a safe micro-organism for production.

Once the genes were cloned, the enzyme it produces, HylP1, was crystallised and the shape of the enzyme was examined.

Dr Black discovered that the enzyme has a rare triple-stranded beta-helix shape, which is similar to only four other enzymes out of the thousands tested in recent years.

''Solving the three dimensional structure of the enzyme means we have a better understanding of how the enzymes bind to other matter and how they work,'' he said.

''We need to understand how the enzyme works to understand how we can stop it.''

Dr Black, 39, from Co Durham, now hopes one of the world's leading pharmaceutical companies will take up his research and use his findings to develop revolutionary life saving drugs.

He added: ''This is a major breakthrough which has the potential to save thousands of lives in the future.''

His findings are published in Proceedings of the National Academy of Sciences of the United States of America - one of the world's most cited multidisciplinary scientific journals.