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Updated: Jun 2, 2026
Novel Diagnostics in Revision Arthroplasty: Implant Sonication and Multiplex Polymerase Chain Reaction
Published on: December 3, 2017
Effect of sonication on staphylococcal and gram-negative biofilms relevant to prosthetic joint infections: an in
Natally Dos Santos Silva1, Cynthia Regina Pedrosa Soares2, Fábio André Brayner Dos Santos2
1Department of Tropical Medicine, Federal University of Pernambuco - UFPE, Hospital das Clínicas, Ground Floor, Hospital das Clínicas, Av. Prof. Moraes Rego, 1235, University City, Recife, 50670-901, Brazil. natally.santos@ufpe.br.
Background:
Periprosthetic joint infections (PJIs) are severe complications of arthroplasty in which biofilm formation on implant surfaces compromises microbiological diagnosis and antimicrobial efficacy. Although staphylococci remain the predominant pathogens, Gram-negative bacilli have increasingly been associated with diagnostic failure and unfavorable clinical outcomes. This study aimed to evaluate the formation, maturation, and structural organization of Gram-positive and Gram-negative bacterial biofilms and to investigate the effects of a standardized sonication protocol on biofilm disruption.
Methods:
Biofilms of Staphylococcus aureus (ATCC 43300), Staphylococcus epidermidis (ATCC 35984), Escherichia coli (ATCC 25922), and Pseudomonas aeruginosa (ATCC 53278) were formed on polyethylene catheter segments for 24, 48, and 72 h and analyzed by scanning electron microscopy (SEM). A standardized sonication protocol was applied to disrupt the extracellular polymeric substance (EPS) matrix, and the resulting sonication fluid was subsequently cultured. Complementary semi-quantitative image-based analysis was performed to compare structural changes after sonication.
Results:
All species developed progressively mature biofilms over time, with increased structural complexity and EPS accumulation at later stages. Gram-positive bacteria formed denser and more compact biofilms, whereas Gram-negative species exhibited more heterogeneous and multilayered architectures. Sonication consistently disrupted biofilm integrity across all species and maturation stages, leading to fragmentation of the EPS matrix and increased cellular dispersion. Semi-quantitative image-based analysis suggested greater dispersion in Gram-negative biofilms and reduction of biofilm structural area in Gram-positive species, with more pronounced effects observed in P. aeruginosa and S. epidermidis. Bacterial growth was observed in cultures obtained from the sonication fluid after the procedure.
Conclusion:
The standardized sonication protocol effectively disrupted biofilms formed by both Gram-positive and Gram-negative bacteria, promoting the release of bacterial cells from the biofilm matrix and reinforcing the potential role of sonication as a complementary diagnostic approach for prosthetic joint infections.
Insights
A standardized sonication protocol effectively disrupts Gram-positive and Gram-negative bacterial biofilms, aiding in the diagnosis of periprosthetic joint infections (PJIs) by releasing bacteria from implant surfaces.
Area of Science:
- Microbiology
- Biomedical Engineering
- Infectious Diseases
Background:
- Periprosthetic joint infections (PJIs) are serious arthroplasty complications.
- Biofilm formation on implants hinders diagnosis and treatment.
- Gram-negative bacilli are increasingly implicated in PJIs, leading to diagnostic challenges.
Purpose of the Study:
- To evaluate biofilm formation and structural organization in Gram-positive and Gram-negative bacteria.
- To investigate the efficacy of a standardized sonication protocol for biofilm disruption.
Main Methods:
- Biofilms of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa were cultured on catheter segments.
- Scanning electron microscopy (SEM) analyzed biofilm structure at 24, 48, and 72 hours.
- A sonication protocol disrupted biofilms, and the released fluid was cultured; image analysis assessed structural changes.
Main Results:
- Biofilms matured over time, showing increased complexity and extracellular polymeric substance (EPS) accumulation.
- Gram-positive biofilms were denser; Gram-negative biofilms were more heterogeneous.
- Sonication disrupted biofilm integrity, fragmented the EPS matrix, and increased bacterial dispersion, with varying effects across species.
Conclusions:
- Sonication effectively disrupted biofilms of both Gram-positive and Gram-negative bacteria.
- The protocol promoted bacterial cell release from the biofilm matrix.
- Sonication shows potential as an adjunctive diagnostic tool for PJIs.
