The antibacterial effect of topical ozone on the treatment of MRSA skin infection

Background: why MRSA skin infections are hard to treat

Staphylococcus aureus is a common cause of skin and soft-tissue infection, and methicillin-resistant Staphylococcus aureus (MRSA) is a strain that no longer responds to many standard antibiotics. Because resistant infections can be difficult and costly to clear, researchers have looked at whether topical ozone, delivered as ozonated water and ozonated oil, might offer an alternative or complementary way to reduce bacterial load on the skin.

Study design: laboratory assays and two clinical cases

The researchers combined laboratory testing with clinical observation. In the laboratory, they tested ozonated water and ozonated oil against two reference bacterial strains, S. aureus (ATCC 6538) and MRSA (ATCC 43300), using plating and Kirby-Bauer disc diffusion assays to measure how quickly the bacteria were killed and to compare zones of inhibition. They then treated two patients who had skin MRSA infection, washing the affected areas with ozonated water followed by application of ozonated oil, and monitored healing over time.

Findings: rapid bacterial killing in the laboratory and healing in both patients

In the laboratory, ozonated water (1 mg/L) eliminated close to 100% of both S. aureus and MRSA within about 1 minute. Ozonated oil killed almost 100% of S. aureus within 5 minutes and almost 100% of MRSA within 15 minutes. Disc diffusion produced inhibition zones of around 17 mm for S. aureus and 13 mm for MRSA with ozonated oil. The authors noted that ozonated water holds its bactericidal effect for roughly 30 minutes, whereas ozonated oil retains antibacterial activity for longer, which is why oil was applied after washing to extend the treatment window. Both patients achieved complete healing without antibiotics, one within about twelve days and the other within roughly two months.

What the authors concluded

The authors concluded that ozone therapy is a potential treatment for S. aureus and MRSA skin infection, describing it as having great efficacy, few side effects and low cost. They positioned topical ozone as a candidate worth further investigation for resistant skin infections rather than an established replacement for antibiotic care.

Limitations of this study

The clinical evidence rested on only two patients, with no control group, no randomisation and no blinding, so the healing seen cannot be attributed to ozone with certainty. The laboratory results were obtained against reference bacterial strains under controlled conditions, which do not necessarily reflect the range of bacteria, wound types and healing responses seen in everyday practice. The paper did not include a formal discussion of its own limitations. Larger controlled trials would be needed before firm conclusions could be drawn about topical ozone for MRSA skin infection.