Contribution of genomics to bacterial pathogenesis

Genomics is changing the landscape of modern biology. The impact is far-rea ching because it provides both the most economical means of acquiring large amounts of information and because it has forced the creation of new techn ologies to exploit this information. Five of the six genomes published in t he year from August 1998 to August 1999 were human pathogens, all of which are highly host-adapted. Four of these are obligate intracellular pathogens and the study of these genomes is providing novel insights into the intric acies of pathogen-host interactions and co-evolution. These genomes are als o significant because they mark the beginning of an important trend in the sequencing of closely related genomes, including the sequencing of more tha n one strain from a single pathogenic species. As comparative genomics trul y comes of age, the ability to compare the genomes of pathogenic and non-pa thogenic organisms will hopefully provide insight into what makes certain b acterial strains and species pathogens.