TB strains in Hyderabad and Andhra Pradesh are of ancestral type; Hyderabad scientists discover new lead molecule for TB

Syed Akbar

Hyderabad: A group of city scientists has discovered a novel lead molecule that could effectively kill the bacteria that cause tuberculosis, while another group has found that the TB strains circulating in Hyderabad and other parts of Andhra Pradesh are of “ancestral” type and, thus, relatively less damaging in nature.

Two teams from the Institute of Life Sciences, an associate institute of the University of Hyderabad, have achieved considerable success in understanding the mechanism of the TB pathogen, particularly why there have been no institutionalised outbreaks of TB in India despite high infection burden, illiteracy, crowding, poverty and not so good hygienic practices.

The novel molecule has shown promising results in the laboratory tests and could emerge as a source of new drug to fight tuberculosis, which is turning resistant to a number of drugs. The anti-TB molecule has successfully killed TB bacterium in test tube studies.

The bacterial strains that cause tuberculosis are broadly divided into “ancestral” and “modern” strains. The strains circulating in India are largely of ancestral type. So far, there have been no studies on the types of strains present in TB patients in Hyderabad or other parts of AP. The University of Hyderabad scientists, led by Dr Niyaz Ahmed, associate professor at the Department of Biotechnology, and their collaborators from the Bhagwan Mahavir Medical Research Centre, have made a pioneering attempt to understand the TB pathogen in this part of the world.

“Significant presence of the ancestral type bacteria in the TB patients from AP assumes importance as M. tuberculosis belonging to the ancestral lineage could show reduced transmission as well as ability to acquire drug resistance as compared to other lineages. This perhaps explains why the Indian population has never suffered institutionalised TB outbreaks as seen in some other parts of the world where ancestral type bacteria are not so prevalent,” said Dr Niyaz Ahmed.

The distribution of the Mycobacterium tuberculosis genotypes in India has been characterised by widespread prevalence of ancestral lineages in the south, and the modern forms predominating in the north of India. The pattern was, however, not clearly known in the south-central region such as Hyderabad and the rest of AP where the prevalence of both tuberculosis and human immunodeficiency virus (HIV) infection is one of the highest in the country.

Moreover, this area has been the hotspot of TB vaccine trials. Correct baseline understanding of the prevalent bacterial types would prevent vaccine escape by any novel strains.