title: Characterization of a mixed MRSA/MRSE biofilm in an explanted total ankle arthroplasty.
abstract: Bacterial biofilms have been observed in many prosthesis-related infections, and this mode of growth renders the infection both difficult to treat and especially difficult to detect and diagnose using standard culture methods. We (1) tested a novel coupled PCR-mass spectrometric (PCR-MS) assay (the Ibis T5000) on an ankle arthroplasty that was culture negative on preoperative aspiration and then (2) confirmed that the Ibis assay had in fact detected a viable multispecies biofilm by further micrographic and molecular examinations, including confocal microscopy using Live/Dead stain, bacterial FISH, and reverse-transcriptase-PCR (RT-PCR) assay for bacterial mRNA. The Ibis technology detected Staphylococcus aureus, Staphylococcus epidermidis, and the methicillin resistance gene mecA in soft tissues associated with the explanted hardware. Viable S. aureus were confirmed using RT-PCR, and viable cocci in the biofilm configuration were detected microscopically on both tissue and hardware. Species-specific bacterial FISH confirmed a polymicrobial biofilm containing S. aureus. A novel culture method recovered S. aureus and S. epidermidis (both methicillin resistant) from the tibial metal component. These observations suggest that molecular methods, particularly the new Ibis methodology, may be a useful adjunct to routine cultures in the detection of biofilm bacteria in prosthetic joint infection.
authors.affiliation: Center for Genomic Sciences, Allegheny-Singer Research Institute, Allegheny General Hospital, Pittsburgh, PA, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Stoodley
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Conti
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: DeMeo
authors.forename: Laura
authors.initials: L
authors.lastname: Nistico
authors.forename: Rachael
authors.initials: R
authors.lastname: Melton-Kreft
authors.forename: Sandra
authors.initials: S
authors.lastname: Johnson
authors.forename: Ali
authors.initials: A
authors.lastname: Darabi
authors.forename: Garth D
authors.initials: GD
authors.lastname: Ehrlich
authors.forename: J William
authors.initials: JW
authors.lastname: Costerton
authors.forename: Sandeep
authors.initials: S
authors.lastname: Kathju
mesh_terms: D000368:Aged; D000843:Ankle Joint / Q000382:microbiology; D058737:Arthroplasty, Replacement, Ankle / Q000009:adverse effects*; D015373:Bacterial Typing Techniques; D018441:Biofilms / Q000145:classification* / Q000254:growth & development; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D013058:Mass Spectrometry / Q000379:methods; D016106:Methicillin Resistance; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D018613:Microscopy, Confocal; D016133:Polymerase Chain Reaction / Q000379:methods; D016459:Prosthesis-Related Infections / Q000382:microbiology*; D013045:Species Specificity; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial