The effect of a component of tea (Camellia sinensis) on methicillin resistance by TS Yam, JM Hamilton-Miller and S Shah
Extracts of tea (Camellia sinensis) can reverse methicillin
resistance in methicillin-resistant Staphylococcus aureus (MRSA)
and also, to some extent, penicillin resistance in
beta-lactamase-producing S. aureus. These
phenomena are explained by prevention of PBP2' synthesis and
inhibition of secretion of beta-lactamase, respectively. Synergy
between beta-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 above-mentioned
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.
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