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Published on: January 7, 2019
Alternating magnetic fields (AMF) and linezolid reduce Staphylococcus aureus biofilm in a large animal implant model
Isuru A Somawardana1, Bibin Prasad2, Walker Kay3
1Texas A&M School of Engineering Medicine, Houston, TX 77030, USA; Solenic Medical, Inc., Addison, TX 75001, USA.
Objectives:
We aimed to evaluate the effectiveness of alternating magnetic fields (AMF) combined with antibiotics in reducing Staphylococcus aureus biofilm on metal implants in a large animal model, compared to antibiotics alone.
Methods:
Metal plates were inoculated with a clinical MRSA strain and then implanted into thirty-three ewes divided into three groups: positive control, linezolid only, and a combination of linezolid and AMF. Animals had either titanium or cobalt-chrome plates and were sacrificed at 5 or 21 days post-implantation. Blood and tissue samples were collected at various time points post-AMF treatment.
Results:
In vivo efficacy studies demonstrated significant biofilm reduction on titanium and cobalt-chrome implants with AMF-linezolid combination treatment compared to controls. Significant bacterial reductions were also observed in surrounding tissues and bones. Cytokine analysis showed improved inflammatory responses with combination therapy, and histopathology confirmed reduced inflammation, necrosis, and bacterial presence, especially at 5 days post-implantation.
Conclusions:
This study demonstrates that combining AMF with antibiotics significantly reduces biofilm-associated infections on metal implants in a large animal model. Numerical simulations confirmed targeted heating, and in vivo results showed substantial bacterial load reduction and reduced inflammatory response. These findings support the potential of AMF as a non-invasive treatment for prosthetic joint infections.
Insights
Combining alternating magnetic fields (AMF) with antibiotics significantly reduced Staphylococcus aureus biofilm on metal implants in a large animal model. This novel approach offers a promising non-invasive treatment for prosthetic joint infections.
Area of Science:
- Biomedical Engineering
- Infectious Diseases
- Materials Science
Background:
- Prosthetic joint infections are a significant clinical challenge, often caused by Staphylococcus aureus biofilms on metal implants.
- Antibiotic resistance and biofilm formation necessitate innovative treatment strategies.
Purpose of the Study:
- To evaluate the efficacy of alternating magnetic fields (AMF) combined with linezolid in reducing Staphylococcus aureus biofilm on metal implants.
- To compare the combination therapy against antibiotic-only treatment in a large animal model.
Main Methods:
- Metal plates (titanium or cobalt-chrome) inoculated with MRSA were implanted in ewes.
- Animals were divided into three groups: control, linezolid alone, and linezolid plus AMF.
- Biofilm reduction, bacterial load in tissues, cytokine levels, and histopathology were assessed at 5 and 21 days post-implantation.
Main Results:
- The AMF-linezolid combination significantly reduced biofilm on both titanium and cobalt-chrome implants.
- Substantial reductions in bacterial load were observed in surrounding tissues and bones.
- Combination therapy led to improved inflammatory responses, reduced necrosis, and decreased bacterial presence.
Conclusions:
- Combining AMF with antibiotics is effective in reducing biofilm-associated infections on metal implants.
- AMF demonstrates potential as a non-invasive therapeutic modality for prosthetic joint infections.
- Numerical simulations confirmed targeted heating, supporting the mechanism of action.
