Scientists decode genomes of diverse T...( Cambridge MA An international colla...)

Cambridge, MA An international collaboration led by researchers in the US and South Africa today announced the first genome sequence of an extensively drug resistant (XDR) strain of the bacterium Mycobacterium tuberculosis, one linked to more than 50 deaths in a recent tuberculosis (TB) outbreak in KwaZulu-Natal, South Africa. As part of this work, genomes of multi-drug resistant (MDR) and drug sensitive isolates were also decoded. Initial comparisons of the genome sequences reveal that the drug-resistant and drug-sensitive microbes differ at only a few dozen locations along the four-million-letter DNA code, revealing some known drug resistance genes as well as some additional genes that may also be important to the spread of TB. The researchers have taken an unusual step of immediately sharing both the genome sequence and their initial analysis far in advance of submitting a scientific paper, in order to accelerate work on drug-resistant TB by researchers around the world.

Tuberculosis is a major threat to global public health that demands new approaches to disease diagnosis and treatment, said Megan Murray, one of the projects principal investigators, an associate member of the Broad Institute of MIT and Harvard and an associate professor at the Harvard School of Public Health. By looking at the genomes of different strains, we can learn how the tuberculosis microbe outwits current drugs and how new drugs might be designed.

Genome information is a powerful tool for understanding the biology of infectious disease, such as tuberculosis, said Eric Lander, founding director of the Broad Institute of Harvard and MIT. It is important that genomic data be made immediately available, particularly to researchers in areas most heavily burdened by disease.

The sequenced strain is responsible for the vast majority of the more than 300 XDR cases identified thus far in the KwaZulu-Natal province of South Africa, said Willem Sturm, one of the pro
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