title: Staphylococcus aureus ST398 gene expression profiling during ex vivo colonization of porcine nasal epithelium.
abstract: BACKGROUND
  Staphylococcus aureus is a common human and animal opportunistic pathogen. In humans nasal carriage of S. aureus is a risk factor for various infections. Methicillin-resistant S. aureus ST398 is highly prevalent in pigs in Europe and North America. The mechanism of successful pig colonization by MRSA ST398 is poorly understood. Previously, we developed a nasal colonization model of porcine nasal mucosa explants to identify molecular traits involved in nasal MRSA colonization of pigs.
  
  
  RESULTS
  We report the analysis of changes in the transcription of MRSA ST398 strain S0462 during colonization on the explant epithelium. Major regulated genes were encoding metabolic processes and regulation of these genes may represent metabolic adaptation to nasal mucosa explants. Colonization was not accompanied by significant changes in transcripts of the main virulence associated genes or known human colonization factors. Here, we documented regulation of two genes which have potential influence on S. aureus colonization; cysteine extracellular proteinase (scpA) and von Willebrand factor-binding protein (vWbp, encoded on SaPIbov5). Colonization with isogenic-deletion strains (Δvwbp and ΔscpA) did not alter the ex vivo nasal S. aureus colonization compared to wild type.
  
  
  CONCLUSIONS
  Our results suggest that nasal colonization with MRSA ST398 is a complex event that is accompanied with changes in bacterial gene expression regulation and metabolic adaptation.
authors.forename: Pawel
authors.initials: P
authors.lastname: Tulinski
authors.affiliation: Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. b.duim@uu.nl.
authors.forename: Birgitta
authors.initials: B
authors.lastname: Duim
authors.forename: Floyd R
authors.initials: FR
authors.lastname: Wittink
authors.forename: Martijs J
authors.initials: MJ
authors.lastname: Jonker
authors.forename: Timo M
authors.initials: TM
authors.lastname: Breit
authors.forename: Jos P
authors.initials: JP
authors.lastname: van Putten
authors.forename: Jaap A
authors.initials: JA
authors.lastname: Wagenaar
authors.forename: Ad C
authors.initials: AC
authors.lastname: Fluit
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D066298:In Vitro Techniques; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics* / Q000472:pathogenicity; D008969:Molecular Sequence Data; D009297:Nasal Mucosa / Q000166:cytology / Q000382:microbiology*; D017423:Sequence Analysis, RNA; D013203:Staphylococcal Infections / Q000382:microbiology / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology*; D014774:Virulence
chemical_list: D001426:Bacterial Proteins