快速篩選抑制Staphylococcus aureus staphyloxanthin生合成抑制劑之方法及應用

Application of a Rapid Screening Method for Staphyloxanthin Biosynthesis Inhibitors

張曉苓(Hsiao-Ling Chang) ； 陳勁初(Chin-Chu Chen)

《檢驗及品保雜誌》 2卷4期 (2013/11) Pp. 198-207

https://doi.org/10.6573/JTQA.201311_2(4).05

摘要

本研究發現金黃色葡萄球菌（Staphylococcus aureus）在胰化酪蛋白大豆洋菜培養基（trypticase soy agar, TSA）上呈現白色菌落，但在營養培養基(nutrient agar, NA)上則可產生金黃色色素；進一步比較兩種培養基組成後，發現色素的合成受碳與氮源種類及比率所影響，於NA中添加單或雙醣碳源，會抑制其色素合成，其中只要有0.1%（w/w）蔗糖或葡萄糖即可抑制色素產生，但麥芽糖則需0.3%（w/w）。添加氮源則可促進色素的合成，其增色強度順序為大豆蛋白腖（soy peptone）大於酵母抽出物（yeast extract）再大於蛋白腖（peptone）。將白色菌落移至營養液培養基（Nutrient broth, NB）於三角瓶中震盪培養時，顯示出比黃色菌落有較長的適應期（lag phase），且對H_2O_2之氧化傷害耐受性較差，此指出金黃色葡萄球菌抗1.5%過氧化氫的能力與色素深淺呈正相關。利用此機轉開發一種可讓色素產生更為明顯之培養基（即nutrient agar w/soy peptone, NASP），並且以之快速大量篩選可抑制金黃色葡萄球菌色素合成之中草藥萃取物，所需判讀時間少於24小時。經篩選141種中藥材之熱水萃取物及甲醇萃取物，結果指出側柏葉、五倍子、訶子、大黃、細辛、兒茶、白芍、烏藥等八種中藥材之水或甲醇萃取物具有抑制金黃色色素staphyloxanthin合成之活性。

關鍵字

抑制色素的中草藥 ； 金黃色葡萄球菌色素

並列摘要

Staphyloxanthin is a virulence factor of Staphylococcus aureus which gives the bacteria a gold color. In this study, we observed the production of the carotenoid when the organism is grown on nutrient agar (NA), but not on tryptic soy agar (TSA) as colonies appeared white. The addition of different carbon sources such as glucose, sucrose or maltose at minimal doses of 0.1%, 0.1% and 0.3% can inhibit carotenoid production, respectively. In contrast, enhanced carotenoid production in S. aureus was observed with supplementation of nitrogen sources, using soy peptone, yeast extract and peptone in decreasing order. Golden S. aureus showed higher H2O2 tolerance and shorter lag phase when grown in nutrient broth compared to bleached colonies. Glucose concentration required for bleached colonies is positively pro-portional to the concentration of soy peptone added in NA. The addition of 1% soy peptone in nutrient agar (NASP) was developed as base medium to screen inhibitory activity of staphyloxanthin from methanol or water extracts of 141 Chinese herbs. Results showed inhibitory activities in methanol extracts of Paeonia lactiflora, Biota orientalis, Ermichebula chebulia, Galla chinensis, Asarum sieboldii, Rheum tanguticum, Lindera strychnifolia, Acacia catechu and water extracts of Biota orientalis, Ermichebula chebulia, Galla chinensis. Soybean protein isolate treatment may affect the minimal inhibitory concentration of some herb extracts.

並列關鍵字

Chinese herb inhibitory activity screen ； Staphylococcus aureus staphyloxanthin