Complete Tuberculosis
4,000 Gene Sequence
Code Cracked
By Patricia Reaney
LONDON, June 10 (Reuters) - A Franco-British team of scientists has cracked the genetic code of tuberculosis, an infectious lung disease that kills more people each year than malaria and AIDS combined. The team has deciphered the entire 4,000-gene sequence, or genome, of the TB bacillus, which should speed the development of new drugs and vaccines against the chronic airborne ailment that has defied scientists' best efforts at eradication. ``I think it will be a landmark in the history of tuberculosis research,'' Dr Stewart Cole, one of the researchers, said in a telephone interview.
``We've identified all the genes and predicted what quite a few of them are doing, so it opens up thousands and thousands of new areas for people to do research in.'' It took the scientists from the Pasteur Institute in France and Britain's Sanger Centre more than two years to complete the joint project, financed by the Wellcome Trust and reported in the science journal Nature on Wednesday. Tuberculosis is not the first disease to be decoded. Scientists have already mapped out the genome for Lyme disease and other bacteria, but the TB bacillus, Mycobacterium tuberculosis, is the most sophisticated sequencing achievement and one that could have far-reaching implications for public health.
``I personally think it is the most important one to date,'' Cole said, adding that sequencing the genome for malaria, another infectious killer, would have similar significance. Douglas Young, a microbiologist at Imperial College School of Medicine in London, said the history of the disease, together with the clues to conquering it, were hidden in the genome. ``Thanks to Cole et al, we now have the sequence of every potential drug target and of every antigen we many wish to include in a vaccine,'' he said in a commentary in Nature. One third of the world's population is infected with the TB bacillus. Three million people die of the disease each year. It is particularly dangerous for HIV sufferers because each disease speeds the progress of the other. TB accounts for nearly one-third of AIDS deaths worldwide. Such is the scale of the epidemic that the World Health Organisation (WHO) predicts that between 1998 and 2020, nearly one billion more people will be infected, 200 million people will become ill and 70 million will die unless controls are strengthened.
New drug-resistant strains are emerging and, in spite of the best efforts of the WHO, the disease has reached epidemic proportions in many poor countries. After being nearly wiped out, it is re-emerging in some rich countries. ``With the globalisation of communities people are moving around the world more easily and more frequently. There is an increasing likelihood that Westerners will get infected if they visit developing countries and this will be imported inadvertently,'' Cole said. The ground-breaking project removes much of the laborious preparatory work for other scientists and pharmaceutical firms, allowing them to focus better on their research. ``It will certainly lead to drug companies and vaccine designers taking more interest in the subject because they have all this free data there at their disposal,'' Cole said. ``If they've got some clever ideas they can just apply them now.''

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