The Antibacterial Assay of Tectorigenin with Detergents or ATPase Inhibitors against Methicillin-Resistant <i>Staphylococcus aureus</i>

다국어 초록 (Multilingual Abstract)

<P>Tectorigenin (TTR) is an O-methylated isoflavone derived from the rhizome of <I>Belamacanda chinensis</I> (L.) DC. It is known to perform a wide spectrum of biological activities such as antioxidant, anti-inflammatory, anti-tumor. The aim of this study is to examine the mechanism of antibacterial activity of TTR against methicillin-resistant <I>Staphylococcus aureus</I> (MRSA). The anti-MRSA activity of TTR was analyzed in combination assays with detergent, ATPase inhibitors, and peptidoglycan (PGN) derived from <I>S. aureus</I>. Transmission electron microscopy (TEM) was used to monitor survival characteristics and changes in <I>S. aureus</I> morphology. The MIC values of TTR against all the tested strains were 125 <I><I>μ</I></I>g/mL. The OD(600) of each suspension treated with a combination of Triton X-100, DCCD, and NaN<SUB>3</SUB> with TTR (1/10 × MIC) had been reduced from 68% to 80%, compared to the TTR alone. At a concentration of 125 <I><I>μ</I></I>g/mL, PGN blocked antibacterial activity of TTR. This study indicates that anti-MRSA action of TTR is closely related to cytoplasmic membrane permeability and ABC transporter, and PGN at 125 <I><I>μ</I></I>g/mL directly bind to and inhibit TTR at 62.5 <I><I>μ</I></I>g/mL. These results can be important indication in study on antimicrobial activity mechanism against multidrug resistant strains.</P>