| TEA TREE OIL EFFECTIVELY KILLS RESISTANT MICROORGANISMS WESTPORT, June 13, 2000 (Reuters Health) Tea tree oil, a substance extracted from the leaves of an Australian tree, is effective in killing a variety of resistant microorganisms commonly found in hospitals, British and Australian researchers report in the May issue of the Journal of Antimicrobial Chemotherapy. Dr. Anna King of St. Thomas' Hospital in London, UK, and colleagues undertook an in-vitro time-kill study of two types of tea tree oil used against a variety of bacteria. The researchers found that the two chemically different types of tea tree oil, standard and cloned, rapidly killed most organisms in less than 60 minutes. Both oils were found to be more active against methicillin-sensitive S. aureus (MSSA) than against methicillin-resistant S. aureus (MRSA). Although both oils killed some organisms, those organisms that were slower to die had a greater susceptibility to the cloned oil. Susceptibility pattern and Gram reaction of the organism did not influence the kill rate. The cloned oil, extracted from a specially bred tree, had a higher content of the active ingredient terpinen-4-ol and a lower content of 1,8 cineole compared to the standard commercially available oil. These results confirm those of other trials, which have shown that tea tree oils with a higher concentration of terpinen-4-ol have enhanced antimicrobial activity, the authors remark. Observing that resistant microorganisms in hospitals and the community are causing problems for both the treatment of patients and infection control, Dr. King's group recommends the use of tea tree oil in topical and hand-washing formulations to reduce "the transmission of many multi-resistant organisms associated with nosocomial infections." J Antimicrob Chemother 2000;45:639-643. |
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