Ultrasound Interventions for Biofilm Management

Biofilms are structured communities of microbial cells encased within a self-produced matrix of extracellular polymeric substances (EPS), which confer marked resistance to antibiotics and host defences. Ultrasound interventions exploit acoustic energy to disrupt biofilm architecture, enhance antimicrobial penetration and stimulate biological processes that convert dormant cells into metabolically active forms more susceptible to treatment. Mechanisms include microbubble oscillation and collapse (acoustic cavitation), generation of localized shear forces, transient pore formation in cell envelopes and augmented elution of drugs from delivery vehicles. Applications span chronic wound care, prevention of device-associated infections and treatment of deep-seated biofilms such as infective endocarditis. Recent advances demonstrate the feasibility of integrating ultrasound with targeted microbubbles, guided-wave transducers or thrombolytic and antibiotic co-therapies to achieve synergistic effects. Emphasis has shifted towards minimally invasive protocols, spatially and temporally controlled dosing, and real-time monitoring of biofilm response. This emerging paradigm addresses the global challenge of antimicrobial resistance by offering adjunct strategies that potentiate existing drugs and forestall the need for device removal or high-dose systemic therapy.

Research from Nature Portfolio

Recent studies have elucidated the synergistic potential of combining ultrasound-targeted microbubble destruction (UTMD) with conventional antibiotics to eradicate implant-associated biofilms. One investigation characterised the disruption of Staphylococcus epidermidis biofilms by UTMD, revealing damage to cell-wall structure and reactivation of metabolic pathways that render cells vulnerable to vancomycin. A catheter-based prototype employing ultrasonic guided waves demonstrated effective prevention of Pseudomonas aeruginosa attachment, with optimised frequencies and wave modes impeding early biofilm deposition without bactericidal ultrasound intensities. In an in vitro model of infective endocarditis, the use of low-frequency ultrasound in concert with an ultrasound contrast agent and combined antibiotic–thrombolytic therapy achieved near-complete degradation of Staphylococcus aureus biofilms on blood clots, highlighting a promising non-invasive strategy for treating deep-seated infections.

Ultrasound Interventions for Biofilm Management publication trend

The graph below shows the total number of articles in ultrasound interventions for biofilm management across all publications each year (not limited to Nature Index journals).

Technical terms

Biofilm: A microbial community encased in a self-produced extracellular matrix adherent to a surface.

Extracellular Polymeric Substance (EPS): A complex mix of polysaccharides, proteins and nucleic acids forming the biofilm scaffold.

Acoustic Cavitation: Formation and violent collapse of microbubbles under ultrasound, generating mechanical forces.

Ultrasound-Targeted Microbubble Destruction (UTMD): Use of ultrasound to oscillate and collapse drug-loaded microbubbles at a target site.

High Intensity Focused Ultrasound (HIFU): Concentrated ultrasound beams that deliver high acoustic pressures to a focal region.

Sonobactericide: A therapeutic approach combining ultrasound, microbubbles and antimicrobials to kill bacteria within biofilms.

References

1. Innovative Strategies Toward the Disassembly of the EPS Matrix in Bacterial Biofilms. Frontiers in Microbiology (2020).
2. Ultrasound‐mediated therapies for the treatment of biofilms in chronic wounds: a review of present knowledge. Microbial Biotechnology (2019).
3. The synergistic bactericidal effect of vancomycin on UTMD treated biofilm involves damage to bacterial cells and enhancement of metabolic activities. Scientific Reports (2018).
4. Preventing microbial biofilms on catheter tubes using ultrasonic guided waves. Scientific Reports (2017).
5. An in vitro proof-of-principle study of sonobactericide. Scientific Reports (2018).
6. Influence of High Intensity Focused Ultrasound on the Microstructure and c-di-GMP Signaling of Pseudomonas aeruginosa Biofilms. Frontiers in Microbiology (2020).