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Dynamics of Pseudomonas aeruginosa genome evolution
Journal article   Open access   Peer reviewed

Dynamics of Pseudomonas aeruginosa genome evolution

Kalai Mathee, Giri Narasimhan, Camilo Valdes, Xiaoyun Qiu, Jody M Matewish, Michael Koehrsen, Antonis Rokas, Chandri N Yandava, Reinhard Engels, Erliang Zeng, …
Proceedings of the National Academy of Sciences - PNAS, Vol.105(8), pp.3100-3105
02/26/2008
DOI: 10.1073/pnas.0711982105
PMCID: PMC2268591
PMID: 18287045
url
https://doi.org/10.1073/pnas.0711982105View
Published (Version of record) Open Access

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.
Biological Sciences horizontal gene transfer comparative genomics core and accessory genomes

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