How much ozone bactericidal activity is compromised by plasma components?

J Appl Microbiol. 2009 May;106(5):1715-21. doi: 10.1111/j.1365-2672.2008.04141.x. Epub 2009 Feb 16.


Aims: Evaluation of bactericidal effect of different concentrations of ozone when used (a) as a gas, or (b) dissolved in saline. The addition of hydrogen peroxide or 4-hydroxynonenal dissolved in saline was also tested, as well as the effect of human plasma.

Methods and results: Staphylococcus aureus, methicillin-resistant Staph. aureus (MRSA), and Pseudomonas aeruginosa, suspended in their culture media were tested. While all bacteria suspended in protein-free saline were killed at high ozone concentrations, they survived when as little as 5% human plasma was present. Hydrogen peroxide was 100-fold less active than ozone and needed to remain in contact with bacteria for at least 60 min. 4-hydroxynonenal (2 micromol l(-1)) was inhibitory for proliferation of both Staph. aureus and MRSA, but not for Ps. aeruginosa.

Conclusions: Ozone and the cascade of its derivative products are potent bactericidal agents, but even small amounts of human plasma, hence of hydro- and liposoluble antioxidants, in bacterial suspensions inhibit oxidation and protect bacteria.

Significance and impact of the study: Any substantial in vivo cytocidal effect of ozone and its derivatives can be excluded. On the other hand, topical and continuous action of various ozone preparations remains valuable in a variety of skin and mucosal infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehydes / pharmacology
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Oxidants, Photochemical / pharmacology*
  • Ozone / pharmacology*
  • Plasma* / physiology
  • Pseudomonas aeruginosa / drug effects*
  • Sodium Chloride / chemistry
  • Sodium Chloride / pharmacology
  • Staphylococcus aureus / drug effects*


  • Aldehydes
  • Oxidants, Photochemical
  • Sodium Chloride
  • Ozone
  • Hydrogen Peroxide
  • 4-hydroxy-2-nonenal