Comparison of the effects in vitro of tea tree oil and plaunotol on methicillin-susceptible and methicillin-resistant strains of Staphylococcus aureus.
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.
Hada
T
T
Department of Microbiology, Showa Pharmaceutical University, Machida, Tokyo, Japan.
Furuse
S
S
Matsumoto
Y
Y
Hamashima
H
H
Masuda
K
K
Shiojima
K
K
Arai
T
T
Sasatsu
M
M
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004224:Diterpenes; D005233:Fatty Alcohols / Q000494:pharmacology*; D006801:Humans; D008712:Methicillin / Q000494:pharmacology; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests / Q000379:methods; D009822:Oils, Volatile / Q000494:pharmacology; D010406:Penicillins / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development; D020947:Tea Tree Oil / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D004224:Diterpenes; D005233:Fatty Alcohols; D009822:Oils, Volatile; D010406:Penicillins; D020947:Tea Tree Oil; C047686:plaunotol; D008712:Methicillin