title: Biofilm development by blastospores and hyphae of Candida albicans on abraded denture acrylic resin surfaces.
abstract: BACKGROUND
  Candida albicans is a known etiologic agent of denture stomatitis. Candida hyphae exhibit the ability to respond directionally to environmental stimuli. This characteristic is thought to be important in the penetration of substrata such as resilient denture liners and host epithelium. It has been suggested that hyphal production also enhances adhesion and survival of Candida on host and denture surfaces. Surface roughness, in addition, can enhance adhesion where stronger interactions occur between cells and surface features of similar dimensions.
  
  
  OBJECTIVE
  The purpose of this study was to assess the development of hyphal and blastospore biofilms on abraded denture acrylic resin specimens and measure the ease of removal of these biofilms.
  
  
  METHODS
  Biofilms were grown for 48 hours on abraded 1-cm² denture acrylic resin specimens from adhered hyphal phase C albicans or from adhered blastospores. Subsequently, all specimens were stained with Calcofluor White and examined with confocal scanning laser microscopy. Biofilms were removed by vortex mixing in sterile phosphate buffered saline solution. Removed cells were filtered (0.2-μm pore size). Filters were dried at 37°C for 24 hours for dry weight measurements. Any cells that remained on the acrylic resin specimens were stained with 0.03% acridine orange and examined with epifluorescence microscopy.
  
  
  RESULTS
  Biofilms grown from both cell types contained all morphologic forms of C albicans. Although the underlying surface topography did not affect the amount of biofilm produced, biofilms grown from hyphal phase Candida were visibly thicker and had greater biomass (P<.05). These biofilms were less easily removed from the denture acrylic resin, especially in the case of rougher surfaces, evidenced by the higher numbers of retained cells (P≤.05).
  
  
  CONCLUSIONS
  The presence of hyphae in early Candida biofilms increased biofilm mass and resistance to removal. Increased surface roughness enhances retention of hyphae and yeast cells, and, therefore, will facilitate plaque regrowth. Therefore, minimization of denture abrasion during cleaning is desirable.
authors.affiliation: Postgraduate student, School of Health Care Science, Manchester Metropolitan University, Manchester, United Kingdom.
authors.forename: Sarah
authors.initials: S
authors.lastname: Jackson
authors.affiliation: Senior Lecturer, School of Health Care Science, Manchester Metropolitan University, Manchester, United Kingdom.
authors.forename: Lisa
authors.initials: L
authors.lastname: Coulthwaite
authors.affiliation: Interim Dean, Touro College of Pharmacy, New York, NY; Professor, Pharmaceutical & Biomedical Sciences, New York Medical College, New York, NY.
authors.forename: Zvi
authors.initials: Z
authors.lastname: Loewy
authors.affiliation: Senior Lecturer, School of Computing, Maths and Digital Technology, Manchester Metropolitan University, Manchester, United Kingdom.
authors.forename: Anthony
authors.initials: A
authors.lastname: Scallan
authors.affiliation: Professor, School of Health Care Science, Manchester Metropolitan University, Manchester, United Kingdom. Electronic address: J.Verran@mmu.ac.uk.
authors.forename: Joanna
authors.initials: J
authors.lastname: Verran
mesh_terms: D000165:Acridine Orange; D000180:Acrylic Resins / Q000737:chemistry*; D000268:Adhesiveness; D001557:Benzenesulfonates; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D018533:Biomass; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology; D015169:Colony Count, Microbial; D003764:Dental Materials / Q000737:chemistry*; D003773:Dental Plaque / Q000382:microbiology; D019554:Dental Restoration Wear; D003819:Denture Bases / Q000382:microbiology*; D003820:Denture Cleansers / Q000494:pharmacology; D005456:Fluorescent Dyes; D006801:Humans; D025301:Hyphae / Q000187:drug effects / Q000254:growth & development*; D018613:Microscopy, Confocal; D019904:Polymethyl Methacrylate / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods; D013172:Spores, Fungal / Q000187:drug effects / Q000254:growth & development*; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000180:Acrylic Resins; D001557:Benzenesulfonates; D003764:Dental Materials; D003820:Denture Cleansers; D005456:Fluorescent Dyes; C007061:C.I. Fluorescent Brightening Agent 28; D019904:Polymethyl Methacrylate; D000165:Acridine Orange