Genetic diversity of pathogenic microorganisms: Basic insights, public health implications and the Indian initiatives

Although pathogenic microorganisms constitute a small proportion of the microbial species, these are characterized by high genetic diversity. In the past decade or so, there has been considerable advancement in understanding the genetic population structures of pathogenic microorganisms that may range from strictly clonal to effectively panmictic. We, now understand that besides the staple mechanisms like point mutations, gene duplication, gene rearrangements and gene loss, horizontal (lateral) gene transfer including pathogenicity islands play an important role in the generation of genetic diversity among microbial pathogens. Understanding genetic diversity of pathogens may have far-reaching implications for public health intervention strategies such as tracking the global spread of pathogens, understanding emergence of new and drugresistant microbes and rational development of diagnostics, therapeutics and vaccines. The study of pathogen diversity may also help us better understand evolution, taxonomy and pathogenicity per se. The endeavours to understand genetic diversity of extant pathogenic microorganisms in India are discussed here.