Scientists belonging to India's National Institute of Immunology are reported to have identified an important element which helps us to understand how the tuberculosis (TB) bacteria survives in the human body. This will help in developing newer and more effective medicines to combat the disease, which claims as many as 2 million lives across the world annually. The research team led by Rajesh S. Gokhale have identified the genes that enable the mycobacterium tuberculosis to acquire the iron it needs to grow and promote the infection of the disease in humans. This discovery will contribute towards combating the multi-drug resistant tuberculosis.
Iron is essential for the mycobacterium to survive and for its enzymatic action, according to Gokhale. It takes the iron from the host cell and to get it the mycobacterium develops siderophores, molecules synthesized by it for its own utility. The new anti-TB drugs being developed can use this pathway to attack the mycobacterium.
When the mycobacterium infects humans, it takes up residence in immune cells called macrophages. To survive in this harsh environment, the mycobacterium, like many other types of bacteria, need iron to carry out life-sustaining functions, such as creating proteins and synthesizing nucleotides to form DNA.
Gokhale's group identified the location of the genes that help the mycobacterium gather the iron more efficiently by observing that the expression of the genes, which increased significantly in response to low iron concentrations.