Tuberculosis Breakthrough: New molecule developed to fight Mycobacterium

2009
By Syed Akbar
Hyderabad, Feb 2: Indian scientists have developed a novel compound that would hit the killer tuberculosis bacteria and cure the disease, which claims about 1000 people everyday in the country.

The novel compound has been successfully tested in laboratory and if it works on human beings, a single drug will be sufficient to deal with the menace of tuberculosis. At present, those suffering from TB are made to take a daily
dose of four drugs. The new development will help in fighting the disease through a single drug. This will save money on medication and prevent side-effects related to multi-drug therapy.

Scientists at the city-based Centre for Cellular and Molecular Biology and the Delhi-based National Institute of Immunology have jointly created the compound. Multi-drug therapy is administered in TB cases as different drugs target different metabolic pathways in Mycobacterium, the causative pathogen, killing it. But the new compound has multiple functions and hits the select metabolic pathways in the bacteria to destroy it.

CCMB scientist Dr Rajan Shankarnarayanan, one of the team members, told this correspondent that the compound stops tuberculosis by hitting four of
the bacterium's crucial metabolic pathways at the same time. "The compound weakens the pathogen before finally destroying it. We have demonstrated it in laboratory tests. However, it takes time before it becomes practical in human beings," he said.

According to Dr Rajan, if everything goes on well, a single drug will help tackle the disease. "A single drug that targets multiple pathways could save time and money by eliminating the need to take so many drugs over a period of say six to nine months," he added.

Mycobacterium tuberculosis, the organism that causes tuberculosis, contains a layer of complex lipids on its outer membrane. The CCMB-NII team found out how the bacterium builds up this complex layer that acts as drug resistant. Once they have solved the mystery, they developed a compound that would hit the metabolic pathways of the causative agent.

Although TB bacteria has been known for centuries, tuberculosis still accounts for more than two million deaths every year. The causative agent has a complex arsenal of virulence factors and has evolved elaborate strategies to escape host surveillance. The cell envelope of the bacteria is endowed with complex lipids, many of which play an important role in its pathogenesis.

"The complex lipids displayed by Mycobacterium tuberculosis are a big factor in its pathogenicity and virulence. Since this single molecule could potentially grind the assembly line to a halt at different stages of infection, this approach provides tremendous opportunity to develop unique antituberculosis drugs," he said.