title: Pseudomonas aeruginosa AES-1 exhibits increased virulence gene expression during chronic infection of cystic fibrosis lung.
abstract: Pseudomonas aeruginosa, the leading cause of morbidity and mortality in people with cystic fibrosis (CF), adapts for survival in the CF lung through both mutation and gene expression changes. Frequent clonal strains such as the Australian Epidemic Strain-1 (AES-1), have increased ability to establish infection in the CF lung and to superimpose and replace infrequent clonal strains. Little is known about the factors underpinning these properties. Analysis has been hampered by lack of expression array templates containing CF-strain specific genes. We sequenced the genome of an acute infection AES-1 isolate from a CF infant (AES-1R) and constructed a non-redundant micro-array (PANarray) comprising AES-1R and seven other sequenced P. aeruginosa genomes. The unclosed AES-1R genome comprised 6.254Mbp and contained 6957 putative genes, including 338 not found in the other seven genomes. The PANarray contained 12,543 gene probe spots; comprising 12,147 P. aeruginosa gene probes, 326 quality-control probes and 70 probes for non-P. aeruginosa genes, including phage and plant genes. We grew AES-1R and its isogenic pair AES-1M, taken from the same patient 10.5 years later and not eradicated in the intervening period, in our validated artificial sputum medium (ASMDM) and used the PANarray to compare gene expression of both in duplicate. 675 genes were differentially expressed between the isogenic pairs, including upregulation of alginate, biofilm, persistence genes and virulence-related genes such as dihydroorotase, uridylate kinase and cardiolipin synthase, in AES-1M. Non-PAO1 genes upregulated in AES-1M included pathogenesis-related (PAGI-5) genes present in strains PACS2 and PA7, and numerous phage genes. Elucidation of these genes' roles could lead to targeted treatment strategies for chronically infected CF patients.
authors.affiliation: Department of Infectious Diseases and Immunology, University of Sydney, Sydney, Australia.
authors.forename: Sharna
authors.initials: S
authors.lastname: Naughton
authors.forename: Dane
authors.initials: D
authors.lastname: Parker
authors.forename: Torsten
authors.initials: T
authors.lastname: Seemann
authors.forename: Torsten
authors.initials: T
authors.lastname: Thomas
authors.forename: Lynne
authors.initials: L
authors.lastname: Turnbull
authors.forename: Barbara
authors.initials: B
authors.lastname: Rose
authors.forename: Peter
authors.initials: P
authors.lastname: Bye
authors.forename: Stuart
authors.initials: S
authors.lastname: Cordwell
authors.forename: Cynthia
authors.initials: C
authors.lastname: Whitchurch
authors.forename: Jim
authors.initials: J
authors.lastname: Manos
mesh_terms: D000293:Adolescent; D001426:Bacterial Proteins / Q000235:genetics; D018441:Biofilms / Q000254:growth & development; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000382:microbiology*; D016680:Genome, Bacterial / Q000235:genetics; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins