title: Staphylococcal biofilm formation on the surface of three different calcium phosphate bone grafts: a qualitative and quantitative in vivo analysis.
abstract: Differences in physico-chemical characteristics of bone grafts to fill bone defects have been demonstrated to influence in vitro bacterial biofilm formation. Aim of the study was to investigate in vivo staphylococcal biofilm formation on different calcium phosphate bone substitutes. A foreign-body guinea-pig infection model was used. Teflon cages prefilled with β-tricalcium phosphate, calcium-deficient hydroxyapatite, or dicalcium phosphate (DCP) scaffold were implanted subcutaneously. Scaffolds were infected with 2 × 10(3) colony-forming unit of Staphylococcus aureus (two strains) or S. epidermidis and explanted after 3, 24 or 72 h of biofilm formation. Quantitative and qualitative biofilm analysis was performed by sonication followed by viable counts, and microcalorimetry, respectively. Independently of the material, S. aureus formed increasing amounts of biofilm on the surface of all scaffolds over time as determined by both methods. For S. epidermidis, the biofilm amount decreased over time, and no biofilm was detected by microcalorimetry on the DCP scaffolds after 72 h of infection. However, when using a higher S. epidermidis inoculum, increasing amounts of biofilm were formed on all scaffolds as determined by microcalorimetry. No significant variation in staphylococcal in vivo biofilm formation was observed between the different materials tested. This study highlights the importance of in vivo studies, in addition to in vitro studies, when investigating biofilm formation of bone grafts.
authors.affiliation: Infectious Diseases Service, Department of Internal Medicine, University Hospital Lausanne (CHUV), Lausanne, Switzerland.
authors.forename: Ulrika
authors.initials: U
authors.lastname: Furustrand Tafin
authors.forename: Bertrand
authors.initials: B
authors.lastname: Betrisey
authors.forename: Marc
authors.initials: M
authors.lastname: Bohner
authors.forename: Thomas
authors.initials: T
authors.lastname: Ilchmann
authors.forename: Andrej
authors.initials: A
authors.lastname: Trampuz
authors.forename: Martin
authors.initials: M
authors.lastname: Clauss
mesh_terms: D000818:Animals; D018441:Biofilms; D016025:Bone Transplantation; D002130:Calcium Phosphates / Q000008:administration & dosage*; D006168:Guinea Pigs; D013210:Staphylococcus / Q000378:metabolism*; D013499:Surface Properties; D054457:Tissue Scaffolds
chemical_list: D002130:Calcium Phosphates; C020243:calcium phosphate