Specialists in Oxford are striving to tackle a virulent strain of drug-resistant tuberculosis at a time when the disease is described as a "world epidemic".

TB now kills more than three million people a year worldwide and London is believed to be close to an epidemic, according to the World Health Organisation.

Those most at risk include the homeless, people in poor housing and those with weak immune systems.

The first drugs to treat TB were introduced in 1944, but strains of Mycobacterium tuberculosis, which causes the disease, have now developed a resistance to four major drugs.

The team at Oxford University, headed by pharmacologist Professor Edith Sim, have discovered that an enzyme N-acetyl transferase (NAT) was active in the TB Mycobacterium. They suspect that the presence of NAT is responsible, at least in part, for the reduced effectiveness of conventional drug treatments against TB.

They believe the secret to treating those strains of TB which are currently drug-resistant may be to identify new enzyme inhibitors which could be given with existing drugs.

Those inhibitors would stop the NAT blocking the action of the preventative drugs.

Story date: Saturday 27 February

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