infections by the opportunistic pathogen Pseudomonas
aeruginosa in immunocompromised patients or in patients with
cystic fibrosis (CF) are the result of unique conditions that allow
this Gram-negative bacterium to colonize the lung. This interaction
between the pathogen and host leads to responses in both cells that
ultimately lead to severe lung degeneration in individuals with CF.
Recently, several new resources and technologies have become available
to investigators, which should greatly accelerate our understanding of
the mechanism of P aeruginosa pathogenesis, as well as of
host defenses. Foremost among these are DNA microarrays, which allow
transcriptional profiling of the partial or entire genetic repertoires
of the pathogen and its host. A comprehensive compendium of expression
profiles will serve in understanding the complex interplay between
pathogen and host during respiratory infections.