Comparison of the effects in vitro of tea tree oil and plaunotol on methicillin-susceptible and methicillin-resistant strains of Staphylococcus aureus

Microbios. 2001:106 Suppl 2:133-41.


The effects in vitro of tea tree oil (TTO) and plaunotol were examined by monitoring the growth of a standard strain of Staphylococcus aureus FDA 209P and of fourteen methicillin-susceptible strains of S. aureus (MSSA), together with twenty methicillin-resistant strains (MRSA). The minimum inhibitory concentrations (MIC) and the doses for 50% inhibition of growth (ID50) were determined by the micro-broth dilution (MD) method, and the broth dilution with shaking (BDS) method, respectively. The MIC of plaunotol for 50 and 90% of the MSSA and MRSA were assessed by the MD method, as 16 microg/ml and > or = 1,024 microg/ml, respectively. No antibacterial effects of TTO on MSSA and MRSA were detected by the MD method. The growth-inhibitory effects of TTO on S. aureus by the BDS method were examined, and it appeared that TTO was effective over a lower range of concentrations than previously reported. It seems that TTO is very effective in vitro against MSSA and MRSA at high concentrations but less effective below 40 microg/ml of TTO.

Publication types

  • Comparative Study

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Diterpenes
  • Fatty Alcohols / pharmacology*
  • Humans
  • Methicillin / pharmacology
  • Methicillin Resistance*
  • Microbial Sensitivity Tests / methods
  • Oils, Volatile / pharmacology
  • Penicillins / pharmacology
  • Staphylococcus aureus / drug effects*
  • Staphylococcus aureus / growth & development
  • Tea Tree Oil / pharmacology*


  • Anti-Bacterial Agents
  • Diterpenes
  • Fatty Alcohols
  • Oils, Volatile
  • Penicillins
  • Tea Tree Oil
  • plaunotol
  • Methicillin