Abstract
Purpose: To confirm that the growth of methicillin-resistant (MRSA) and methicillin-susceptible (MSA) Staphylococcus aureus is inhibited by green tea and to investigate the mechanism responsible for this action. Design: In vitro growth of clinical isolates of MRSA and MSA on tea-enhanced and normal media, with and without added iron, zinc, calcium, magnesium and silver. Materials and Methods: Green tea extract was incorporated in agar media, to which clinical isolates of bacteria were applied. The inhibitory concentrations were recorded and electron microscopy was carried out to demonstrate cell morphology. Metal-impregnated paper discs were used to counter the inhibitory properties of the tea. Results: Green tea inhibits the growth of both MRSA and MSA. Cell division was seen to be abnormal and this effect was overcome by the addition of ferrous iron or, in some cases, silver. Conclusions: Subject to clinical confirmation, green tea has great potential for therapeutic use in the treatment of MRSA and MSA infections.