The effect of a component of tea (Camellia sinensis) on methicillin resistance, PBP2' synthesis, and beta-lactamase production in Staphylococcus aureus.

Extracts of tea (Camellia sinensis) can reverse methicillin resistance in methicillin-resistant Staphylococcus aureus (MRSA) and also, to some extent, penicillin resistance in -lactamaseproducing S. aureus. These phenomena are explained by prevention of PBP2 synthesis and inhibition of secretion of -lactamase, respectively. Synergy between -lactams and tea extracts were demonstrated by disc diffusion, chequerboard titration and growth curves. Partition chromatography of an extract of green tea on Sephadex LH-20 yielded several fractions, one of which contained a virtually pure compound that showed the abovementioned activities, at concentrations above about 2 mg/L. The observed activities are novel and distinct from the previously reported direct antibacterial activity of tea extracts. Prevention of PBP2 synthesis offers an interesting possible new approach for the treatment of infections caused by MRSA.