Niyaz Ahmed BVSc MS PhD
Staff Scientist and Group Leader
Cent DNA Fingerprinting Diag
Hyderabad 500076 India
| Academic and Community Activity General Secretary, ISOGEM Section Editor, PLoS ONE Assoc. Editor, Infectious Agents & Cancer Assoc. Editor, Ann Clin Microb Antimicrobials Faculty Member, Faculty of 1000 Biology and Medicine Corres. Fellow, European Helicobacter Study Group |
| Research interests in this lab constitute analyzing trends in genomic diversity of bacterial pathogens with reference to evolution of survival mechanisms, metabolic machinery and virulence apparatuses etc. and their impact on dissemination dynamics, invasion, persistence, signaling events, molecular pathogenesis, strain evolution and prevention measures. Pathogen genome is analyzed through decipherment of genomic and proteomic diversity as a function of flexibility in gene content (plasticity zones, large deletions), gene order (transposition), and gene regulation (allelic variation, synonymous substitutions, strand displacements), possibly aimed at evolution of fittest genotypes, corresponding to changing host niches and the environment. Ahmed is an elected member of the National Academy of Sciences, India and is currently studying global diversity and evolution of two important pathogens, viz, M. tuberculosis and Helicobacter pylori. Another important pathogen of recent interest is Leptospira interrogans where the research theme is - how a saprophytic organism evolves into a deadly human pathogen? Dr Ahmed is the founder of the ISOGEM, a scientific society headquartered at Sassari in Italy and serves as its General Secretary. Dr Ahmed is a co-principal investigator in the Mycobacterium w (Mycobacterium indicus pranii) genome program, India's first whole genome sequencing project. He has published more than 75 research papers in scientific journals of high value. He is the Section Editor of PLOS ONE, a top tier Open Access journal of high repute. Ahmed also serves as Associate Editor of Annals of Clinical Microbiology and Antimicrobials, Associate Editor of Infectious Agents and Cancer and Associate Editor of Acta Veterinaria Scandinavica. Ahmed is a Faculty of the Faculty of 1000 Biology, the next generation literature evaluation and awareness service for medicine. He was recently elected as the Fellow of the European Helicobacter Study Group (EHSG). Lay summary of ongoing projects and principal achievements Helicobacter pylori, Mycobacterium tuberculosis and leptospira and are some of the bacterial pathogens that trigger diseases with a complex interplay between infection dynamics, pathogen biology and host immune responses. The whole genome sequence determination has greatly facilitated our understanding of these pathogens. The human gastric pathogen H. pylori is presumed to be co-evolved with its human host and is again a very highly diverse and robust pathogen. Our 'geographic genomics' study tested the theory that H. pylori existed in humans as a benign bacterium for thousands of years until it acquired some virulence factors from the microorganisms abundant in the human societies of the neolithic period, after the domestication of agriculture and livestock. We found traces of East Asian ancestry in the gene pool of Native Peruvian strains (Amerindian?). This finding supported ancient human migration across the Bering-strait (20,000 years BP). We also attempted to support the idea that the major single virulence factor of the bacterium, the cag Pathogenicity Island (cagPAI) was acquired during different times, at different places in the world and from a 'local' microbial source. We followed this with theoretical approaches to find significant overlap among the H. pylori population expansion time and domestication of agriculture in the world. This study provides some new insights into the ancient origins and diversity of H. pylori and the significance of such diversity in the development of gastroduodenal pathology. Why has this bacterium survived for this long time in humans? Does this association makes the colonization beneficial or of low biological cost? These are the questions that need to be answered in the near future. Another research project within our group looks at the pathogenic roles of different H. pylori proteins encoded by the core genome (housekeeping) and flexible genome (plasticity region cluster) content of the bacillus. Tuberculosis is the disease with a highest morbidity and mortality worldwide. The disease haunts millions of people in India with a huge death rate. The genetic diversity and evolutionary history of the underlying M. tuberculosis strains are largely unknown in the context of this country that has earned dubious distinctions for tuberculosis prevalence. Our ongoing, large-scale analysis of hund- -reds of strains of tubercle bacilli highlighted a clear predominance of ancestral M. tuberculosis genotypes in the Indian subcontinent, compared to other regions of the world, and support the opinion that India is a historically ancient endemic focus of tuberculosis. It is hypothesized that such 'ancient' bacilli are relatively 'docile' than some of the highly 'killer' ones such as the highly dissemina- -ting Beijing genotypes with an inherent propensity to acquire multiple drug resistance (MDR) and are spreading in India through major metropolitan cities. Beijing strains are likely to evade and replace ancestral reservoirs of M. tuberculosis in the country. This is perhaps a major issue that needs to be addressed in the post-genomic scenario, with the same magnitude of zeal that researchers have shown towards drug discovery and diagnostic or vaccine development. Leptospirosis is another major pestilence, a worldwide zoonosis caused by the spirochetes of the genus Leptospira. The leptospires have been extremely diverse pathogens having more than three hundred different strains or serovars with specific geographic distribution. But this enormous inventory of serovars, based mainly on an ever-changing surface antigen repertoire, throws an artificial and unreliable scenario of strain diversity. It is therefore difficult to track strains whose molecular identity keeps changing according to the host and the environmental niches they inhabit and cross through. To address this problem, we have developed highly sophisticated genotyping systems based on integrated genome analysis approaches to correctly identify and track leptospiral strains. These approaches are expected to greatly facilitate epidemiology of leptospirosis apart from deciphering the origins and evolution of leptospires in a global sense. Last updated: Nov 21, 2008. |
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| Ahmed Lab @ CDFD |
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Group Members and Co-workers |
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Important publications List of Our Publications @ PubMed 1.Ahmed N, Dobrindt U, Hacker J and Hasnain SE |
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Quick Links / Current Topics
| Popular highlights of our activity History debugged: Down to Earth Magazine Birth place of Tuberculosis: New Scientist (London) Birth place of TB: The Times of India (Delhi) The bug's revenge: The Telegraph (Kolkata) Genome of M. indicus: Wall Street Journal |