Detection of Alpha-Toxin and Other Virulence Factors in Biofilms of Staphylococcus aureus on Polystyrene and a Human Epidermal Model

• Published in: PloS one 2016-01, Vol.11 (1), p.e0145722-e0145722
• Main Authors: den Reijer, P M, Haisma, E M, Lemmens-den Toom, N A, Willemse, J, Koning, R I, Koning, R A, Demmers, J A A, Dekkers, D H W, Rijkers, E, El Ghalbzouri, A, Nibbering, P H, van Wamel, W
• Format: Article
• Language: English
• Subjects: Anti-infective agents; Antibiotics; Antimicrobial agents; Bacterial Proteins - biosynthesis; Bacterial Proteins - genetics; Bacterial Toxins - biosynthesis; Bacterial Toxins - genetics; Bacterial Toxins - metabolism; Biofilms; Biofilms - growth & development; Dermatology; Dosage and administration; Drug resistance; Epidermis - microbiology; Ethics; Fibronectin; Fibronectin-binding protein; Gene Expression Regulation, Bacterial; Genes, Reporter; Glucosaminidase; Gram-positive bacteria; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Hemolysin Proteins - biosynthesis; Hemolysin Proteins - genetics; Hemolysin Proteins - metabolism; Humans; Immunomodulation; Infectious diseases; Keratinocytes - microbiology; Leukocidins - biosynthesis; Leukocidins - genetics; Lipase; Methicillin; Methicillin-Resistant Staphylococcus aureus - genetics; Methicillin-Resistant Staphylococcus aureus - growth & development; Methicillin-Resistant Staphylococcus aureus - pathogenicity; Microbial mats; Models, Biological; Modulators; Nuclease; Pathogenesis; Pathogens; Polystyrene; Polystyrene resins; Polystyrenes - chemistry; Primary Cell Culture; Promoter Regions, Genetic; Protein B; Proteins; Proteomics; Resistance factors; Staphylococcus aureus; Staphylococcus infections; Toxins; Virulence; Virulence factors; Virulence Factors - biosynthesis; Virulence Factors - genetics; α-Toxin
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0145722

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. 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. 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.