"Waking up" tuberculosis bacteria lying dormant in the body could help treat the disease faster and more effectively, researchers suggest.
There is a growing problem of drug-resistant TB in the developing world
A team from University College London say a protein that acts as an 'alarm clock' stirs the bacteria into life,
Patients often stop taking TB drugs early because they feel better.
But writing in Nature Structural & Molecular Biology, the researchers warn this means the dormant bacteria which remain can be activated months later.
World Health Organization figures suggest 8.8 million people worldwide are infected with TB.
It is estimated that two million deaths resulted from TB in 2002 alone.
TB usually attacks the lungs but it can affect almost any part of the body.
People with weakened immune systems, such as people with HIV, are at increased risk. The elderly, the malnourished, people who misuse alcohol and IV drug users are also at high risk.
While antibiotics are available to treat the disease, there is a growing problem of drug-resistant TB in the developing world.
'Unlock the secrets'
The UCL team analysed the molecular structure of resuscitation promoting factor (RpF) within the bacteria.
They now hope to deduce exactly how it stirs the bacteria into life.
Once they have done this, they believe they will be able to create a synthetic version of the protein which could be used as a treatment.
Dr John Ward, of the Department of Biochemistry and Molecular Biology at UCL, said: "The antibiotics we give to patients are effective in killing active TB bacteria but not ones that are lying dormant.
"People feel better quickly after starting their treatment course, which should last six months, and then they stop taking their medication.
"But four or five months later, the bacteria lying dormant in the body is activated."
'Not a cure'
He added: "We need to unlock the secrets behind the RpF protein and mimic its effect in a molecule that we can give orally - so that we can wake-up all the bacteria - in the same way that we give antibiotics.
"It's not the cure for TB but these dormant TB bacteria have been a problem."
Professor Peter Davies, a consultant at Liverpool's Cardiothoracic Centre, said: "It is only when TB bacteria are reproducing and dividing that you have the chance to get the antibiotics through and kill them.
"But that happens very infrequently, usually once every month or two months, which is why people have to take a six-month course of antibiotics - to ensure all the bacteria in their bodies are killed.
"But if you could make the bacteria active, and therefore dividing, you may only need to give one or two months' worth of treatment, which would be better because of the problems in people finishing long courses of treatments."