Effect of green tea extract and EGCG on mRNA expression of β-galactosidase gene inS. moorei. Bacteria were incubated (8 h) in the presence of compounds at MIC (500 and 250 μg/ml for green tea extract and EGCG, respectively), and ½ MIC (250 and 125 μg/ml for green tea extract and EGCG, respectively). Data are expressed as means ± standard deviations. The expression was normalized to 16S rRNA. *, significantly different (P < 0.01) compared to untreated control.