Waking dormant TB bacteria

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http://news.bbc.co.uk/1/hi/health/4450057.stm

'Alarm clock' protein TB aid hope 

There is a growing problem of drug-resistant TB in the developing

world

" Waking up " tuberculosis bacteria lying dormant in the body could

help treat the disease faster and more effectively, researchers

suggest.

A team from University College London found a protein that acts as

an 'alarm clock' to stir 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.

  " Dormant TB bacteria have been a problem "

Dr Ward, University College London

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 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 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. "