Title:

The genomics of adaptation and parallelism associated with chronic infection by the opportunistic pathogen Pseudomonasaeruginosa

Abstract:

Of the many complications associated with the genetic disorder cystic fibrosis (CF), arguably the most difficult to manage and treat is chronic infection of the CF airways by the Gram-negative opportunistic pathogen Pseudomonas aeruginosa. Infection occurs in 60-70% of adult CF patients in Canada andis associated with increased morbidity and mortality, irrespective of lung function.  Most infections result ultimately from colonization by environmental strains and can remain permanently associated with the host for decades.  At its core, this transition from free-living strain to chronic infection is an evolutionary process of adaptation to a novel environment: natural selection, imposed by the physical conditions of the host environment and its immune system and the biotic environment of competing strains and species, sorts among genetic variation in the pathogen population introduced through mutation and/or recombination to cause adaptation to the prevailing conditions of growth. My lab has been studying this process using a combination of experimental evolution and comparative genomics with both laboratory and clinical isolates of P. aeruginosa.  I will present the results of recent studies aimed at uncovering the genes responsible for adaptation to life in the CF lung and the fundamental evolutionary processes responsible.