冬凌草提取物对金黄色葡萄球菌生物膜形成的抑制作用

Inhibition Activity of Rabdosia rubescens Extract on Biofilm Formation of Staphylococcus aureus

研究了冬凌草提取物对金黄色葡萄球菌生物被膜形成的影响。采用结晶紫染色法评价了冬凌草提取物在不同质量浓度和不同添加时间下干预金黄色葡萄球菌生物被膜的作用。实验结果表明,冬凌草提取物对金黄色葡萄球菌的MIC和MBC分别为125μg/mL和250μg/mL,在亚抑菌浓度,冬凌草提取物对金黄色葡萄球菌生物膜形成的干预作用不明显;当冬凌草提取物质量浓度大于1倍MIC时,其对金黄色葡萄球菌生物膜形成的有明显的抑制作用,在生物膜形成的初始时间(0 h)添加药物抑制效果最佳,2MIC冬凌草提取物对金黄色葡萄球菌成膜的抑制率达到79%以上;24 h后添加抑制作用较弱,抑制率仅有60%左右。采用银染法和荧光染色法研究了冬凌草提取物对金黄色葡萄球菌生物膜的清除效果和抑制胞外多糖的合成,实验结果也表明,在亚抑菌浓度,冬凌草提取物对金黄色葡萄球菌生物膜的清除和胞外多糖合成的抑制作用很弱,当冬凌草提取物质量浓度大于1 MIC时,在生物膜形成的初始时间(0 h)添加药物,对金黄色葡萄球菌生物膜清除效果明显,胞外多糖的合成也受到显著的抑制。本研究为冬凌草提取物在食品防腐和保鲜,以及无抗饲料的广泛应用提供理论基础。

The effect of Rabdosia rubescens extract on biofilm formation of Staphylococcus aureus was tested. Inhibitory ac- tivity of R. rubescens extract with different concentrations and different addition times on the biofilm formation of S. aureus were analyzed by crystal violet staining assay and sliver staining methods. The results showed that the MIC and MBC of R. rubescens crude extract against S. aureus were 125 μg/mL and 250 μg/mL,respectively. Under sub-MIC concentra- tions,the intervention effect of R. rubescens extract on hiofilm formation of S. aureus was not obvious,but when the con- centration of R. rubescens crude extracts was more than double MIC, it can significantly inhibit the biofilm formation of S. aureus and the best inhibition effect can be achieved after adding drugs at the initial time of biofilm formation. The inhi- bition rate was over 79% when the concentrations of R. rubescens crude extracts were 2MIC. The inhibition rate was only 60% at 24 h of biofilm formation after adding drugs. The eradication effect on biofilm and the inhibition of extracellular polysaccharide（EPS） synthesis were studied by using crystal violet staining assay and sliver staining methods. The re- suits also showed that the eradication effect of R. rubescens crude extracts on biofilm and the inhibition of its on extracel- lular polysaccharide synthesis were weak. An obvious decrease of S. aureus biofilms and EPS were observed after adding drugs at the initial time of biofilm formation when the concentration of R. rubescens crude extracts was more than double MIC. This study provided a theoretical basis for the wide application of R. rubescens extract in food storage and preserva-tion, as well as antibiotic-free feed.