HIMEDIA HiCrome 顯色培養基（／產色培養基／呈色培養基） |
顯色培養基（／產色培養基／呈色培養基）
( Chromogenic / Fluorogenic Culture Media )
顯色培養基一般是在培養基中加入檢測特定菌種的特殊性底物。
(一種或多種顯色劑(目測) 或 熒光顯色劑(紫外燈照射觀察) )
該特殊性底物 與 特定微生物自身代謝產生的酶 會產生顯色(產色)情形，
藉此直接觀察菌落顏色即可對菌種做出鑑定，
其反應的靈敏度和特異性大大優於傳統培養基。
顯色培養基通常為乾粉狀，容易儲存。
加蒸餾水溶解後，部分產品無須高壓滅菌，培養時間依具體培養基而定，
通常是18-24小時，比傳統時間顯著縮短。
HiMedia – M1598 HiCrome™ Enrichment Broth Base for EC 0157:H7 |
Recommended for isolation and selective differentiation of Escherichia coli O157:H7 from food and environmental samples by chromogenic method.
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Principle and Interpretation
March and Ratnam (1) reported the inability of Escherichia coli O157:H7 to ferment sorbitol while developing Sorbitol MacConkey medium. Subsequently Thomson et al (2) observed the absence of b-glucuronidase activity in E. coli O157:H7 from a variety of samples by direct culture. The medium contains Tryptone that provides nitrogenous, carbonaceous compounds and other essential growth nutrients. Sorbitol is the fermentable carbohydrate, bile salt mixture inhibits most of the grampositive organisms. Addition of tellurite (FD230) makes the medium more specific and selective. The bluish colour development of E. coli and Klebsiella in the medium is due to the enzymes b-D-galactosidase and b-D-glucuronidase respectively that cleaves the chromogenic substrates present in chromogenic mixture. However E. coli O157:H7 gives a purple colour to the medium due to the absence of b-glucuronidase and its inability to ferment sorbitol.
March and Ratnam (1) reported the inability of Escherichia coli O157:H7 to ferment sorbitol while developing Sorbitol MacConkey medium. Subsequently Thomson et al (2) observed the absence of b-glucuronidase activity in E. coli O157:H7 from a variety of samples by direct culture. The medium contains Tryptone that provides nitrogenous, carbonaceous compounds and other essential growth nutrients. Sorbitol is the fermentable carbohydrate, bile salt mixture inhibits most of the grampositive organisms. Addition of tellurite (FD230) makes the medium more specific and selective. The bluish colour development of E. coli and Klebsiella in the medium is due to the enzymes b-D-galactosidase and b-D-glucuronidase respectively that cleaves the chromogenic substrates present in chromogenic mixture. However E. coli O157:H7 gives a purple colour to the medium due to the absence of b-glucuronidase and its inability to ferment sorbitol.
原理與解釋
March和Ratnam（1）報導了在開發山梨醇MacConkey培養基時大腸桿菌O157：H7不能發酵山梨糖醇。 隨後，Thomson等（2）通過直接培養觀察到來自各種樣品的大腸桿菌O157：H7中不存在β-葡醣醛酸糖苷酶活性。 該培養基含有胰蛋白腖，可提供含氮，含碳化合物和其他必需的生長營養素。 山梨糖醇是可發酵的碳水化合物，膽鹽混合物抑制大多數生殖器官。 添加亞碲酸鹽（FD230）使介質更具特異性和選擇性。 培養基中大腸桿菌和克雷伯氏菌的藍色顯色分別是由於酶b-D-半乳糖苷酶和b-D-葡醣醛酸酶分別裂解了生色混合物中存在的生色底物。 然而，由於不存在β-葡醣醛酸糖苷酶及其不能發酵山梨糖醇，大腸桿菌O157：H7給培養基呈現紫色。
March和Ratnam（1）報導了在開發山梨醇MacConkey培養基時大腸桿菌O157：H7不能發酵山梨糖醇。 隨後，Thomson等（2）通過直接培養觀察到來自各種樣品的大腸桿菌O157：H7中不存在β-葡醣醛酸糖苷酶活性。 該培養基含有胰蛋白腖，可提供含氮，含碳化合物和其他必需的生長營養素。 山梨糖醇是可發酵的碳水化合物，膽鹽混合物抑制大多數生殖器官。 添加亞碲酸鹽（FD230）使介質更具特異性和選擇性。 培養基中大腸桿菌和克雷伯氏菌的藍色顯色分別是由於酶b-D-半乳糖苷酶和b-D-葡醣醛酸酶分別裂解了生色混合物中存在的生色底物。 然而，由於不存在β-葡醣醛酸糖苷酶及其不能發酵山梨糖醇，大腸桿菌O157：H7給培養基呈現紫色。
HiMedia Laboratories 的顯色培養基 產品以HiCrome為開頭命名
相較於 法國Chromagar、德國Merck、英國Oxoid、美國Remel 其他顯色培養基品牌，
HiMedia 顯色培養基產品 更多元，更豐富，品質優越。