A little known mycobacterial organism Mycobacterium indicus pranii (MIP) from India could be the earliest ancestor of the 'generalist' branch of mycobacterial pathogens, according to a study1 .
University of Hyderabad researchers suggest that the prominent 'generalist' pathogen M. avium — a big threat to AIDS patients — descended from (MIP) as did its close associate M. avium paratuberculosis (MAP), the agent of Crohn's disease in humans and Johne's disease in cattle.
The researchers found that the MIP and the MAP bacilli initially inhabited water bodies and infected marine organisms that were eaten up by fishes and finally arrived on soil through bird-droppings.
The 'generalist' bacteria infect anything from cockroaches to human and are capable of surviving in soil and water as against the human-adapted 'specialists' such as tubercle and leprosy bacilli. TB, a disease that killed about 1.7 million humans last year alone, is caused by a member of the mycobacterial family of pathogens.
The MIP bacilli, also called Mycobacterium w (Mw), were first isolated in India by G. P. Talwar at the All India Institute of Medical Sciences, New Delhi in the eighties and is currently used, after an extensive clinical trial, as an immunotherapeutic against leprosy in India. The success with MIP- based leprosy vaccine has led to human clinical evaluations of MIP in interventions against HIV-AIDS, psoriasis and bladder cancer in India.
The comparative genomics study based on complete sequence of the MIP organism reports observations based on the first ever whole genome sequencing project from India.
The authors of this work are from: Pathogen Evolution Laboratory, Centre for DNA Fingerprinting and Diagnostics (CDFD), Hyderabad, India; Interdisciplinary Centre for Plant Genomics, Department of Plant Molecular Biology, University of Delhi, New Delhi, India; Department of Biochemistry, University of Delhi; University of Hyderabad, Hyderabad, India; Institute of Life Sciences, University of Hyderabad; Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India.
