Characterization of a mixed MRSA/MRSE biofilm in an explanted total ankle arthroplasty

• Published in: FEMS immunology and medical microbiology Vol. 62; no. 1; pp. 66 - 74
• Main Authors: Stoodley, Paul, Conti, Stephen F., DeMeo, Patrick J., Nistico, Laura, Melton-Kreft, Rachael, Johnson, Sandra, Darabi, Ali, Ehrlich, Garth D., Costerton, J. William, Kathju, Sandeep
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-06-2011; Blackwell
• Subjects: Aged; Ankle; Ankle Joint - microbiology; Arthroplasty; Arthroplasty, Replacement, Ankle - adverse effects; Bacterial Typing Techniques; Bacteriology; biofilm; Biofilms; Biofilms - classification; Biofilms - growth & development; Biological and medical sciences; Cocci; Confocal microscopy; DNA, Bacterial - analysis; DNA, Bacterial - genetics; DNA, Bacterial - isolation & purification; Drug resistance; Female; Fluorescence in situ hybridization; Fundamental and applied biological sciences. Psychology; Humans; In Situ Hybridization, Fluorescence; Infection; Joint diseases; joint infection; Mass Spectrometry - methods; MecA protein; Metals; Methicillin; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus - classification; Methicillin-Resistant Staphylococcus aureus - genetics; Methicillin-Resistant Staphylococcus aureus - growth & development; Methicillin-Resistant Staphylococcus aureus - isolation & purification; Microbiology; Microscopy, Confocal; Miscellaneous; mRNA; PCR; Polymerase chain reaction; Polymerase Chain Reaction - methods; Prosthesis-Related Infections - microbiology; prosthetic; Prosthetics; Soft tissues; Species Specificity; Stains; Staphylococcal Infections - microbiology; Staphylococcus aureus; Staphylococcus aureus - classification; Staphylococcus aureus - genetics; Staphylococcus aureus - growth & development; Staphylococcus aureus - isolation & purification; Staphylococcus epidermidis; joint infection; prosthetic; arthroplasty; PCR; biofilm; Polymerase chain reaction; Immunology; Biofilm; Explant; Bacteria; Micrococcales; Micrococcaceae; Staphylococcus aureus
• ISSN: 0928-8244; 1574-695X
• DOI: 10.1111/j.1574-695X.2011.00793.x

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.