title: A modified chronic infection model for testing treatment of Staphylococcus aureus biofilms on implants.
abstract: Bacterial biofilms causing implant-associated osteomyelitis is a severe complication with limited antimicrobial therapy options. We designed an animal model, in which implant associated osteomyelitis arise from a Staphylococcus aureus biofilm on a tibia implant. Two bioluminescently engineered (luxA-E transformed), strains of S. aureus were utilized, Xen29 and Xen31. Biofilm formation was assessed with epifluorescence microscopy. Quantitative measurements were performed day 4, 6, 8, 11 and 15 post-surgery. Bacteria were extracted from the biofilm by sonication and the bacterial load quantified by culturing. Biofilm formation was evident from day 6 post-implantation. Mean bacterial load from implants was ∼1×10(4) CFU/implant, while mean bacterial load from infected tibias were 1×10(6) CFU/bone. Bioluminesence imaging revealed decreasing activity throughout the 15-day observation period, with signal intensity for both strains reaching that of the negative control by day 15 while there was no significant reduction in bacterial load. The model is suitable for testing antimicrobial treatment options for implant associated OM, as treatment efficacy on both biofilm and viable counts can be assessed.
authors.affiliation: Department of Infectious Diseases, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Microbiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Nis Pedersen
authors.initials: NP
authors.lastname: Jørgensen
authors.forename: Rikke L
authors.initials: RL
authors.lastname: Meyer
authors.affiliation: Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark.
authors.forename: Rikke
authors.initials: R
authors.lastname: Meyer
authors.affiliation: Department of Biomedicine, Faculty of Health Sciences Aarhus University, Aarhus, Denmark.
authors.forename: Frederik
authors.initials: F
authors.lastname: Dagnæs-Hansen
authors.affiliation: Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark.
authors.forename: Kurt
authors.initials: K
authors.lastname: Fuursted
authors.affiliation: Department of Infectious Diseases, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Eskild
authors.initials: E
authors.lastname: Petersen
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D058491:Bacterial Load; D018441:Biofilms; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D010019:Osteomyelitis / Q000188:drug therapy / Q000382:microbiology; D019736:Prostheses and Implants / Q000009:adverse effects*; D016459:Prosthesis-Related Infections / Q000188:drug therapy* / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology*; D013211:Staphylococcus aureus; D014640:Vancomycin / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin