Cold Atmospheric Plasma-Aerosol Treatment of Equine Antibiotic-Resistant Wound Infection: A Preliminary Case Series.

Cold Atmospheric Plasma-Aerosol (CAP-A) treatment was tested on antibiotic-resistant wound infections in horses, showing promising results for reducing multi-resistant bacteria and promoting wound healing without using antibiotics.

Background and Importance

• Wound infections are a common complication in horses undergoing wound treatment.
• Secondary bacterial colonization often involves antibiotic-resistant microorganisms, posing a significant challenge.
• This issue is critical from a “One Health Concept” perspective, linking human, animal, and environmental health concerns.
• Conventional antibiotic treatments require antibiograms to assess resistance, which is time-consuming.
• Multi-resistant pathogens, including MRSA and resistant Gram-negative bacteria, complicate treatment further.

Objective and Methodology

• The study was a preliminary case series involving four horses aged 5 weeks to 11 years, each presenting with infected wounds.
• Horses were treated with Cold Atmospheric Plasma-Aerosol (CAP-A) as a standalone therapy without antibiotics.
• Treatment protocol:
  • Once daily sessions lasting up to two months.
  • Each session comprised two 3-minute nebulization cycles of CAP-A.
• Microbiological samples were collected before treatment to identify antibiotic-resistant pathogens and after treatment to evaluate microbial reduction.
• Photographic documentation was used to monitor wound healing progression.

Key Findings

• Multiple multi-resistant bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and multi-resistant Gram-negative bacteria, were identified in all horses prior to treatment.
• After 10 days of CAP-A treatment:
  • MRSA was no longer detectable by culture methods.
  • Significant reduction in microbial load of pathogenic bacteria was observed.
  • Advanced wound healing was noted, with visual evidence supporting clinical improvement.
• CAP-A treatment was well tolerated by horses with no reported discomfort during sessions.

Conclusions and Implications

• CAP-A therapy shows promise as a non-pharmacological alternative to antibiotics for treating antibiotic-resistant wound infections in horses.
• This method specifically demonstrated efficacy against difficult-to-treat multi-resistant bacteria such as MRSA.
• The therapy led to both microbiological clearance and clinical healing without antibiotic use, potentially reducing antimicrobial resistance development.
• Due to the small sample size and preliminary nature of the study, findings need validation through a larger scale, prospective clinical trial.
• Future research should include:
  • Control groups (placebo or standard care) to better evaluate CAP-A’s effectiveness.
  • Longer-term follow-up to assess sustained healing and recurrence rates.
  • Broader inclusion of case types and ages to generalize results.