title: Detection of Alpha-Toxin and Other Virulence Factors in Biofilms of Staphylococcus aureus on Polystyrene and a Human Epidermal Model.
abstract: OBJECTIVE
  The ability of Staphylococcus aureus to successfully colonize (a)biotic surfaces may be explained by biofilm formation and the actions of virulence factors. The aim of the present study was to establish the presence of 52 proteins, including virulence factors such as alpha-toxin, during biofilm formation of five different (methicillin resistant) S. aureus strains on Leiden human epidermal models (LEMs) and polystyrene surfaces (PS) using a competitive Luminex-based assay.
  
  
  RESULTS
  All five S. aureus strains formed biofilms on PS, whereas only three out of five strains formed biofilms on LEMs. Out of the 52 tested proteins, six functionally diverse proteins (ClfB, glucosaminidase, IsdA, IsaA, SACOL0688 and nuclease) were detected in biofilms of all strains on both PS and LEMs. At the same time, four toxins (alpha-toxin, gamma-hemolysin B and leukocidins D and E), two immune modulators (formyl peptide receptor-like inhibitory protein and Staphylococcal superantigen-like protein 1), and two other proteins (lipase and LytM) were detectable in biofilms by all five S. aureus strains on LEMs, but not on PS. In contrast, fibronectin-binding protein B (FnbpB) was detectable in biofilms by all S. aureus biofilms on PS, but not on LEMs. These data were largely confirmed by the results from proteomic and transcriptomic analyses and in case of alpha-toxin additionally by GFP-reporter technology.
  
  
  CONCLUSIONS
  Functionally diverse virulence factors of (methicillin-resistant) S. aureus are present during biofilm formation on LEMs and PS. These results could aid in identifying novel targets for future treatment strategies against biofilm-associated infections.
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: P M
authors.initials: PM
authors.lastname: den Reijer
authors.affiliation: Department of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands.|Department of Dermatology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: E M
authors.initials: EM
authors.lastname: Haisma
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: N A
authors.initials: NA
authors.lastname: Lemmens-den Toom
authors.affiliation: Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Willemse
authors.forename: R I
authors.initials: RI
authors.lastname: Koning
authors.affiliation: Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: R A
authors.initials: RA
authors.lastname: Koning
authors.affiliation: Proteomics Centre, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: J A A
authors.initials: JA
authors.lastname: Demmers
authors.affiliation: Proteomics Centre, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: D H W
authors.initials: DH
authors.lastname: Dekkers
authors.affiliation: Proteomics Centre, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Rijkers
authors.affiliation: Department of Dermatology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: El Ghalbzouri
authors.affiliation: Department of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: P H
authors.initials: PH
authors.lastname: Nibbering
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: W
authors.initials: W
authors.lastname: van Wamel
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development*; D004817:Epidermis / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006460:Hemolysin Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000382:microbiology; D007956:Leukocidins / Q000096:biosynthesis / Q000235:genetics; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity*; D008954:Models, Biological; D011137:Polystyrenes / Q000737:chemistry; D061251:Primary Cell Culture; D011401:Promoter Regions, Genetic; D037521:Virulence Factors / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D006460:Hemolysin Proteins; D007956:Leukocidins; D011137:Polystyrenes; D037521:Virulence Factors; C037956:gamma-hemolysin, Staphylococcus aureus; C021091:staphylococcal alpha-toxin; D049452:Green Fluorescent Proteins