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.

Bacteriophage Lysin CF-301, a Potent Antistaphylococcal Biofilm Agent

“…The efficient removal and killing of biofilm bacteria by CF-301 are particularly ideal features for catheter lock solutions. Catheter lock solutions are often composed of heparin and high concentrations of antibiotics (in LR solution) for instillation into the catheter lumen to sterilize, treat catheter-related bacteremia, minimize complications, and avoid catheter removal (55). In support of such a use, we demonstrated potent CF-301 activity in LR solution, with and without heparin, over a 3-week period at 37°C (Table S7).…”

Cis-2-decenoic Acid Inhibits S. aureus Growth and Biofilm In Vitro: A Pilot Study

“…In vivo studies are required for more comprehensive evaluation of cell and tissue response prior to clinical use of C2DA in preventative therapies. Another limitation was that we used a single bacterial strain to model biofilm formation in vivo, whereas clinical biofilms had a polymicrobial nature and were likely to be populated with Gram-positive, Gram-negative, and fungal microorganisms [15,42]. We chose to study MRSA biofilm first, since they have been a primary organism in many orthopaedic infection cases and presented substantial clinical and financial burdens [28,38,39].…”

Successful Identification of Pathogens by Polymerase Chain Reaction (PCR)-Based Electron Spray Ionization Time-of-Flight Mass Spectrometry (ESI-TOF-MS) in Culture-Negative Periprosthetic Joint Infection

“…Second, slow-growing pathogens may not be identified within the standard incubation period; moreover, increasing the incubation period would increase the rate of falsepositive results 19,20 . Third, formation of complex biofilms on prosthetic surfaces decreases the quantity of free-floating bacteria, consequently leading to a greater likelihood of a negative culture [21][22][23][24] . Finally, antibiotic prophylaxis can result in negative cultures 25,26 .…”