title: Dynamics of Pseudomonas aeruginosa genome evolution.
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.
authors.affiliation: Department of Molecular Microbiology and Immunology, College of Medicine, School of Computing and Information Sciences, College of Engineering, Florida International University, Miami, FL 33199, USA.
authors.forename: Kalai
authors.initials: K
authors.lastname: Mathee
authors.forename: Giri
authors.initials: G
authors.lastname: Narasimhan
authors.forename: Camilo
authors.initials: C
authors.lastname: Valdes
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Qiu
authors.forename: Jody M
authors.initials: JM
authors.lastname: Matewish
authors.forename: Michael
authors.initials: M
authors.lastname: Koehrsen
authors.forename: Antonis
authors.initials: A
authors.lastname: Rokas
authors.forename: Chandri N
authors.initials: CN
authors.lastname: Yandava
authors.forename: Reinhard
authors.initials: R
authors.lastname: Engels
authors.forename: Erliang
authors.initials: E
authors.lastname: Zeng
authors.forename: Raquel
authors.initials: R
authors.lastname: Olavarietta
authors.forename: Melissa
authors.initials: M
authors.lastname: Doud
authors.forename: Roger S
authors.initials: RS
authors.lastname: Smith
authors.forename: Philip
authors.initials: P
authors.lastname: Montgomery
authors.forename: Jared R
authors.initials: JR
authors.lastname: White
authors.forename: Paul A
authors.initials: PA
authors.lastname: Godfrey
authors.forename: Chinnappa
authors.initials: C
authors.lastname: Kodira
authors.forename: Bruce
authors.initials: B
authors.lastname: Birren
authors.forename: James E
authors.initials: JE
authors.lastname: Galagan
authors.forename: Stephen
authors.initials: S
authors.lastname: Lory
mesh_terms: D001483:Base Sequence; D003550:Cystic Fibrosis / Q000150:complications*; D004777:Environment; D019143:Evolution, Molecular; D016680:Genome, Bacterial; D023281:Genomics; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D011552:Pseudomonas Infections / Q000209:etiology / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA