title: Staphylococcus aureus biofilm formation and antibiotic susceptibility tests on polystyrene and metal surfaces.
abstract: OBJECTIVE
  We compared the MBEC™-HTP assay plates made of polystyrene with metal discs composed of TMZF(®) and CrCo as substrates for biofilm formation.
  
  
  RESULTS
  Staphylococcus aureus was grown on polystyrene and on metal discs made of titanium and chrome-cobalt. Antibiotic susceptibility was assessed by examining the recovery of cells after antibiotic exposure and by measuring the biofilm inhibitory concentration (BIC). The minimal inhibitory concentration (MIC) was assessed with planktonic cells. Bacterial growth was examined by scanning electron microscopy. The antibiotic concentration for biofilm inhibition (BIC) was higher than the MIC for all antibiotics. Microscopic images showed the biofilm structure characterized by groups of cells covered by a film.
  
  
  CONCLUSIONS
  All models allowed biofilm formation and testing with several antibiotics in vitro. Gentamicin and rifampicin are the most effective inhibitors of Staph. aureus biofilm-related infections. We recommend MBEC™-HTP assay for rapid testing of multiple substances and TMZF(®) and CrCo discs for low-throughput testing of antibiotic susceptibility and for microscopic analysis.
  
  
  CONCLUSIONS
  In vitro assays can improve the understanding of biofilms and help developing methods to eliminate biofilms from implant surfaces. One advantage of the TMZF(®) and CrCo discs as biofilm in vitro assay is that these metals are commonly used for orthopaedic implants. These models are usable for future periprosthetic joint infection studies.
authors.affiliation: Experimental Orthopaedics, Medical University of Innsbruck, Innsbruck, Austria. debora.coraca-huber@i-med.ac.at
authors.forename: D C
authors.initials: DC
authors.lastname: Coraça-Huber
authors.forename: M
authors.initials: M
authors.lastname: Fille
authors.forename: J
authors.initials: J
authors.lastname: Hausdorfer
authors.forename: K
authors.initials: K
authors.lastname: Pfaller
authors.forename: M
authors.initials: M
authors.lastname: Nogler
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms; D005839:Gentamicins / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D011137:Polystyrenes; D019736:Prostheses and Implants / Q000382:microbiology*; D012293:Rifampin / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D011137:Polystyrenes; D012293:Rifampin