title: Significant differences in type IV pilin allele distribution among Pseudomonas aeruginosa isolates from cystic fibrosis (CF) versus non-CF patients.
abstract: Type IV pili (TFP) are important colonization factors of the opportunistic pathogen Pseudomonas aeruginosa, involved in biofilm formation and attachment to host cells. This study undertook a comprehensive analysis of TFP alleles in more than 290 environmental, clinical, rectal and cystic fibrosis (CF) isolates of P. aeruginosa. Based on the results, a new system of nomenclature is proposed, in which P. aeruginosa TFP are divided into five distinct phylogenetic groups. Each pilin allele is stringently associated with characteristic, distinct accessory genes that allow the identification of the allele by specific PCR. The invariant association of the pilin and accessory genes implies horizontal transfer of the entire locus. Analysis of pilin allele distribution among isolates from various sources revealed a striking bias in the prevalence of isolates with group I pilin genes from CF compared with non-CF human sources (P<0.0001), suggesting this particular pilin type, which can be post-translationally modified by glycosylation via the action of TfpO (PilO), may confer a colonization or persistence advantage in the CF host. This allele was also predominant in paediatric CF isolates (29 of 43; 67.4 %), showing that this bias is apparent early in colonization. Group I pilins were also the most common type found in environmental isolates tested. To the authors' knowledge, this is the first example of a P. aeruginosa virulence factor allele that is strongly associated with CF isolates.
authors.affiliation: Department of Microbiology, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.|Centre for Infection and Biomaterials Research, Hospital for Sick Children Research Institute and Department of Surgery, University of Toronto, 7142A Elm Wing, 555 University Avenue, Toronto, ON, Canada M5G 1X8.
authors.forename: Julianne V
authors.initials: JV
authors.lastname: Kus
authors.affiliation: Adult Cystic Fibrosis Clinic, St Michael's Hospital, Toronto, ON, Canada.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Tullis
authors.affiliation: Department of Microbiology, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.
authors.forename: Dennis G
authors.initials: DG
authors.lastname: Cvitkovitch
authors.affiliation: Department of Microbiology, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.|Centre for Infection and Biomaterials Research, Hospital for Sick Children Research Institute and Department of Surgery, University of Toronto, 7142A Elm Wing, 555 University Avenue, Toronto, ON, Canada M5G 1X8.
authors.forename: Lori L
authors.initials: LL
authors.lastname: Burrows
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D000595:Amino Acid Sequence; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000382:microbiology*; D004783:Environmental Microbiology; D036781:Fimbriae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000302:isolation & purification; D012007:Rectum / Q000382:microbiology; D016415:Sequence Alignment
chemical_list: D036781:Fimbriae Proteins