Researchers Explore Effect of Low-Dose Gaseous Ozone on Pathogenic Bacteria

Treatment of chronically infected wounds is a challenge, and bacterial environmental contamination is a growing issue in infection control. Ozone may have a role in these situations. Fontes, et al. (2012) sought to determine whether a low dose of gaseous ozone/oxygen mixture eliminates pathogenic bacteria cultivated in Petri dishes.
A pilot study with six bacterial strains was conducted using different concentrations of ozone in an ozone-oxygen mixture to determine a minimally effective dose that completely eliminated bacterial growth. The small and apparently bactericidal gaseous dose of 20 mug/mL ozone/oxygen (1:99) mixture, applied for 5min under atmospheric pressure was selected. In the 2nd phase, eight bacterial strains with well characterized resistance patterns were evaluated in vitro using agar-blood in adapted Petri dishes (105 bacteria/dish). The cultures were divided into three groups: 1) ozone-oxygen gaseous mixture containing 20 mug of O3/mL for 5 minutes; 2) 100 percent oxygen for 5 minutes; 3) baseline, no gas was used.
The selected ozone dose was applied to the following eight strains: Escherichia coli, oxacillin-resistant Staphylococcus aureus, oxacillin-susceptible Staphylococcus aureus, vancomycin-resistant Enterococcus faecalis, extended-spectrum beta-lactamase-producing Klebsiella pneumoniae, carbapenem-resistant Acinetobacter baumannii, Acinetobacter baumannii susceptible only to carbapenems, and Pseudomonas aeruginosa susceptible to imipenem and meropenem. All isolates were completely inhibited by the ozone-oxygen mixture while growth occurred in the other two groups.
The researchers concluded that a single topical application by nebulization of a low ozone dose completely inhibited the growth of all potentially pathogenic bacterial strains with known resistance to antimicrobial agents. Their research was published in BMC Infectious Diseases. 

Reference: Fontes B, et al. Effect of low-dose gaseous ozone on pathogenic bacteria. BMC Infectious Diseases 2012, 12:358 doi:10.1186/1471-2334-12-358