Positive Health Online

Abstract

MESSAGER and co-workers, Discipline of Microbiology, School of Biomedical and Chemical Sciences, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia, have measured the antibacterial activity of tea tree oil.

Background

The aim of the study was to measure the activity of tea tree oil and tea tree oil-containing products according to the EN 1276 and EN 12054 European suspension methods.

Methodology

The activity of different concentrations of tea tree oil as well as of two different skin washes and a hand rub were assessed in the EN 12054 and EN 1276 tests, the latter both in perfect conditions and in the presence of an interfering agent. Activities against Staphylococcus aureus, Acinetobacter baumannii, Escherichia coli and Pseudomonas aeruginosa were measured.

Results

The efficacy of tea tree oil appeared to be dependent on the formulation and the concentration tested, the concentration of interfering substances and the organism tested. 5% tea tree oil achieved a better than 10,000-fold reduction in cell numbers of P. aeruginosa after 5 minutes of contact time. 5% tea tree oil in detergent was significantly more active against E. coli and P. aeruginosa than against S. aureus and A. baumannii. Alcoholic skin wash and alcoholic hand rub seem to be more effective than tea tree oil alone.

Conclusion

The authors have developed some formulations that are at present being tested as agents for hospital handwashing procedures and may ultimately help overcome the 'hospital superbug' problem.

References

Messager S, Hammer KA, Carson CF, Riley TV. Assessment of the antibacterial activity of tea tree oil using the European EN 1276 and EN 12054 standard suspension tests. Journal of Hospital Infection 59 (2): 113-125, Feb 2005.