德江天麻蛋白对金黄色葡萄球菌的抑制作用研究

Inhibitory effect of Gastrodia elata protein of Dejiang on Staphylococcus aureus

为了探讨天麻蛋白对金黄色葡萄球菌(金葡菌)的抑制作用,本研究以德江天麻为原料,提取天麻蛋白,检测天麻蛋白在不同浓度和不同时间条件下对金葡菌抑菌率的影响.利用实时荧光定量PCR检测金葡菌的毒力基因的表达变化,用试剂盒检测天麻蛋白对金葡菌细胞外碱性磷酸酶含量的影响和总肠毒素表达量的影响,用细菌计数法检测天麻蛋白对感染金葡菌小鼠死亡保护率和肺部细菌数量的影响.结果显示,天麻蛋白分子量分布于25~35 kDa,其对金葡菌的抑菌率呈现出剂量依赖性,天麻蛋白的抑菌率随着与金葡菌作用时间的延长而增加;天麻蛋白可抑制金葡菌毒力基因sea,agrA,hla及总肠毒素的表达,又可增加金葡菌细胞外碱性磷酸酶含量,并且均具有浓度依赖性;天麻蛋白降低了金葡菌肺炎小鼠死亡率,减少了小鼠肺脏中金葡菌的定植数量.以上结果说明,天麻蛋白在宿主体内外均可抑制金葡菌的生长.

In order to investigate the inhibitory effect of Gastrodin elata protein on Staphylococcus aureus(S.aureus),Gastrodin elata of Dejiang was used as a raw material to extract Gastrodin elata protein,and effects of Gastrodia elata protein on the antibacterial rate of S.aureus under different concentrations and different time conditions were detected in this study.The expression changes of virulence genes of S.aureus was detected by real-time fluorescence quantitative PCR.Effects of Gastrodia elata protein on the extracellular alkaline phosphatase content and total enterotoxin expression of S.aureus were detected by kits.Effects of Gastrodia elata protein on the death protection rate and the number of lung bacteria in mice infected with S.aureus were detected by bacterial counting method.The results showed that the molecular weight of Gastrodia elata protein is in the range of 25~35 kDa.The inhibitory rate of Gastrodia elata protein to S.aureus is dose-dependent and is gradually enhanced with the prolongation of the interaction time with S.aureus.Expression levels of virulence genes sea,agrA,hla,and total enterotoxin of S.aureus are inhibited by S.aureus,and the extracellular alkaline phosphatase content of S.aureus is enhanced by Gastrodia elata in a concentration-dependent manner.The mortality of S.aureus pneumonia mice and the number of S.aureus colonization in the lungs of mice are decreased by Gastrodia elata protein.All results showed that the growth of S.aureus is inhibited by Gastrodia elata protein both in vitro and in vivo.