茶葉副產物之萃取物對於抑制金黃色葡萄球菌生成生物膜之評估

Abstract

金黃色葡萄球菌 (Staphylococcus aureus) 是引起食物中毒常見的病原菌之一，同時也是院內感染的主要致病菌。其主要原因與金黃色葡萄球菌在食品器具及醫療器材表面上所形成的生物膜有關。生物膜為細菌群聚生長的一種結構，在生理特性與毒性等皆與個體有不同的機制表現，進而導致更高的抗藥性及抵抗免疫系統的能力。目前已有研究指出，茶葉萃取物能夠有效的抑制造成蛀牙的變形鏈球菌 (Streptococcus mutans) 在牙齒表面形成生物膜。因此，本研究將從茶葉副產物中萃取及分離不同的區分層，測量各區分層中活性物質如酚類、黃酮類物質以及皂苷的含量。再分別以抑菌圈的方式測試具有抗菌功效的區分層，以及抑制金黃色葡萄球菌生成生物膜的活性試驗。結果顯示，乙酸乙酯-F3 (EA-F3) 為皂苷含量最多的區分層，其可抑制金黃色葡萄球菌生長的最低抑菌濃度 (MIC) 為0.5 mg/ml。同時以此濃度稀釋成1/2倍，1/4倍，1/8倍後，也能有效的抑制金黃色葡萄球菌生物膜的生成。另外，酚類含量較多的乙酸乙酯-F2 (EA-F2) 同樣也具有抑菌以及抑制金黃色葡萄球菌生長的功效，但其效果則在各菌株間有差異性。另以掃描式電子顯微鏡觀察此生物膜的外觀發現，經過EA-F3作用的組別，金黃色葡萄球菌呈現較分散的狀態，且其所產生的生物膜也相對的較少。未來將進一步了解此區分層對抑制金黃色葡萄球菌生物膜形成的作用機制。

Staphylococcus aureus is a common foodborne pathogen causing food poisoning and also the major pathogen of nosocomial infections at the same time. The main reason for causing infections of S. aureus is the ability of forming biofilm on the food processing equipment and medical devices. Biofilm is a microbially-derived sessile community; they have different performance mechanism individually in physiological characteristics and toxicity, increasing drug resistance and the resistance ability of the immune system compare to the planktonic cells. Previous studies reported that tea leaves extracts have the potential to inhibit biofilm formation of Streptococcus mutans, a major bacteria of dental decay on the surface of teeth. Thus, this study will extract and separate the different bioactive compounds from tea waste, investigate their antimicrobial activity and inhibition of S. aurues biofilm production. As the result, EA-F3 fraction which consists of large amounts of tea saponin, is capable to inhibit the growth of three tested S. aureus and its MIC, 0.5 mg/ml, also effective on inhibit S. aureus biofilm formation. At the same time, EA-F2 fraction that composed of tea polyphenol also effective on the antimicrobial and inhibition of biofilm formation with MIC, 0.5 mg/ml. But the results are different among three of the tested strains. The observation with scanning electron microscope showed that S. aureus grew loose and scattered, less secretion of polysaccharides after treated with both fractions. However, both EA-F2 and EA-F3 fraction could not remove the pre-formed biofilm with the same concentration or the increasing concentrations.