title: Yersinia pseudotuberculosis harbors a type IV pilus gene cluster that contributes to pathogenicity.
abstract: Fimbriae have been shown to play an essential role in the adhesion of pathogenic gram-negative bacteria to host cells. In the enteroinvasive bacterium Yersinia pseudotuberculosis, we characterized a previously unknown 11-kb chromosomal locus involved in the synthesis of type IV pili. The locus consists of 11 open reading frames forming a polycistronic unit and encoding putative Pil proteins, PilLMNOPQRSUVW. When introduced into Escherichia coli, the Y. pseudotuberculosis operon reconstituted bundles of filaments at a pole on the bacterial surface, demonstrating that the pil locus was functional in a heterogenous genetic background. Environmental factors regulated transcription of the Y. pseudotuberculosis operon; in particular, temperature, osmolarity, and oxygen tension were critical cues. Deletion of the type IV pilus gene cluster was associated with a reduction of Y. pseudotuberculosis pathogenicity for mice infected orally. Forty-one percent of Y. pseudotuberculosis strains isolated from human or animal sources harbored the type IV pilus locus. Therefore, the pil locus of Y. pseudotuberculosis might constitute an "adaptation island," permitting the microorganism to colonize a vast reservoir.
authors.affiliation: Equipe Mixte Inserm (E9919)-Université (JE2225)-Institut Pasteur de Lille, Institut de Biologie de Lille, France.
authors.forename: François
authors.initials: F
authors.lastname: Collyn
authors.forename: Marie-Annick
authors.initials: MA
authors.lastname: Léty
authors.forename: Shamila
authors.initials: S
authors.lastname: Nair
authors.forename: Vincent
authors.initials: V
authors.lastname: Escuyer
authors.forename: Amena
authors.initials: A
authors.lastname: Ben Younes
authors.forename: Michel
authors.initials: M
authors.lastname: Simonet
authors.forename: Michaël
authors.initials: M
authors.lastname: Marceau
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005260:Female; D010861:Fimbriae, Bacterial / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D005810:Multigene Family; D009876:Operon; D014158:Transcription, Genetic; D015011:Yersinia pseudotuberculosis / Q000235:genetics* / Q000472:pathogenicity