Dynamics of Pseudomonas aeruginosa genome evolution.

Proc Natl Acad Sci U S A
Authors
Keywords
Abstract

One of the hallmarks of the Gram-negative bacterium Pseudomonas aeruginosa is its ability to thrive in diverse environments that includes humans with a variety of debilitating diseases or immune deficiencies. Here we report the complete sequence and comparative analysis of the genomes of two representative P. aeruginosa strains isolated from cystic fibrosis (CF) patients whose genetic disorder predisposes them to infections by this pathogen. The comparison of the genomes of the two CF strains with those of other P. aeruginosa presents a picture of a mosaic genome, consisting of a conserved core component, interrupted in each strain by combinations of specific blocks of genes. These strain-specific segments of the genome are found in limited chromosomal locations, referred to as regions of genomic plasticity. The ability of P. aeruginosa to shape its genomic composition to favor survival in the widest range of environmental reservoirs, with corresponding enhancement of its metabolic capacity is supported by the identification of a genomic island in one of the sequenced CF isolates, encoding enzymes capable of degrading terpenoids produced by trees. This work suggests that niche adaptation is a major evolutionary force influencing the composition of bacterial genomes. Unlike genome reduction seen in host-adapted bacterial pathogens, the genetic capacity of P. aeruginosa is determined by the ability of individual strains to acquire or discard genomic segments, giving rise to strains with customized genomic repertoires. Consequently, this organism can survive in a wide range of environmental reservoirs that can serve as sources of the infecting organisms.

Year of Publication
2008
Journal
Proc Natl Acad Sci U S A
Volume
105
Issue
8
Pages
3100-5
Date Published
2008 Feb 26
ISSN
1091-6490
URL
DOI
10.1073/pnas.0711982105
PubMed ID
18287045
PubMed Central ID
PMC2268591
Links
Grant list
S06 GM008205 / GM / NIGMS NIH HHS / United States
R01 GM068516 / GM / NIGMS NIH HHS / United States
R15 AT002626 / AT / NCCIH NIH HHS / United States
S06 GM08205 / GM / NIGMS NIH HHS / United States
GM068516 / GM / NIGMS NIH HHS / United States
1-R15-AT002626-01 / AT / NCCIH NIH HHS / United States
R25 GM61347 / GM / NIGMS NIH HHS / United States
R25 GM061347 / GM / NIGMS NIH HHS / United States
HHSN26620040001C / PHS HHS / United States