Globally, tuberculosis (TB) is a major cause of infectious disease deaths. Nearly 2 billion people, comprising roughly one third of the worlds population, are thought to carry M. tuberculosis, the culprit bacterium. Major obstacles to controlling the disease stem from the microbes ability to evade current treatments, which typically require prolonged use by patients and are often not curative. MDR strains, for example, are resistant to two of the most effective first-line TB drugs, and XDR strains can circumvent first-line as well as some second-line drugs. Adding to the problem, inefficient diagnostic methods for TB make it difficult for doctors to determine whether an individual harbors a drug-resistant strain, often delaying proper therapy.
To shed light on the genetic changes that mediate drug resistance, an international team of scientists undertook a large-scale effort to sequence the genomes of drug sensitive, MDR, and XDR TB isolates of a strain responsible for the current XDR-TB epidemic in KwaZulu-Natal, South Africa. This strain corresponds to one found in patients in Tugela Ferry, a rural town in KwaZulu-Natal that has recently experienced a severe outbreak of XDR TB among patients infected with the human immunodeficiency virus (HIV). There, 52 of 53 people infected with this strain died. The research reflects a collaboration among researchers in the Microbial Sequencing Center at the Broad Institute of Harvard and MIT, Megan Murray of the Harvard School of Public Health, and Willem Sturm and his colleagues at the Nelson Mandela Medical School in South Africa.
The draft genome sequences
|Contact: Robin Herman|
Harvard School of Public Health