Mycobacterium indicus pranii: Indian scientists have decoded the genetic makeup of a friendly bacterium, which incidentally is the progenitor of harmful tuberculosis and leprosy bacteria the worldwide

By Syed Akbar
Hyderabad: Indian scientists have decoded the genetic makeup
of a friendly bacterium, which incidentally is the progenitor of
harmful tuberculosis and leprosy bacteria the worldwide. This is the
first time that an Indian team has decoded the complete genome of a
bacterium without the support of foreign scientists.

The decoding of the genome of the soil-living and friendly
Mycobacterium indicus pranii (MIP) will give scientists an insight
into the evolutionary history of the bacteria responsible for
tuberculosis and leprosy. It will also tell the genetic story of how a
harmless bacterial species like MIP had undergone changes over a
period to give rise to the most challenging health problem in the form
of TB. The decoding of the genome is crucial in evolving effective
control measures against mycobacterial infections including leprosy
and TB.

Scientists from the University of Delhi South Campus, the University
of Hyderabad, the Indian Institute of Technology, Delhi, and the
National Institute of Plant Genome Research were involved in the
decoding of MIP genome. Eminent scientist Dr Seyed E Hasnain, who is
no associated with the IIT, Delhi, led the research team. The other team
members are Anil K Tyagi, Vikram Saini, Saurabh Raghvanshi, Jitendra P Khurana,
Niyaz Ahmed and Akhilesh K Tyagi.

“Understanding the evolutionary and genomic mechanisms responsible for
turning the soil-derived saprophytic mycobacteria into lethal
intracellular pathogens is a critical step towards the development of
strategies for the control of mycobacterial diseases,” said Dr
Hasnain, adding that MIP is of specific interest because of its unique
immunological and evolutionary significance.

He told this correspondent that evolutionarily, MIP is the progenitor
of opportunistic pathogens belonging to M avium complex and is endowed
with features that place it between saprophytic (feeding on decaying
material) and pathogenic (disease-causing) species. Interestingly, the
MIP has been used in the treatment of leprosy and India has
successfully controlled it. However, the fight against TB is still on
as it is increasingly becoming resistant to known drugs.

“We show, for the first time for Mycobacterium, that MIP genome has
mosaic architecture. These gene acquisitions have led to the
enrichment of selected gene families critical to MIP physiology,” he
said. The genome of MIP is 5.6 Mb in size and is shaped by a large
number of lateral gene acquisitions.

Mycobacterium indicus pranii has been named after India (indicus) and
senior scientist Dr Gursaran Pran Talwar (pranii). It lives in soil
and feeds on decaying plant and animal material. It shares antigens
with both Mycobacterium leprae (leprosy) and M tuberculosis (TB) and
provides protection against TB infection in mice.