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 – M1575A_HiCrome™ EC 0157 H7 Selective Agar Base Modified |
Recommended for selective isolation and easy detection of Escherichia coli O157:H7 from food samples.
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Principle and Interpretation
Enterohaemorragic E. coli strains are also termed as verocytotoxinproducing E.coli (VTEC/ EHEC). Although many different serotypes of Escherichia coli are known to produce verocytotoxin (2) those of Escherichia coli O157:H7 and O157:H are so far the common types causing human infections. O157 VTEC strains have several unusual biochemical characters that are exploited in methods for their laboratory identification. They belong to the minority of E. coli that are b-glucuronidase negative and do not ferment sorbitol or rhamnose within 24 hours. These can be isolated from faecal specimens by plating on media containing D-sorbitol instead of lactose. HiCrome™ EC O157:H7 Selective Agar Base, Modified is based on the formulation described by Rappaport and Henigh (1). The medium contains sorbitol and a proprietary chromogenic mixture instead of lactose and indicator dyes respectively. The chromogenic substrate is specifically and selectively cleaved by Escherichia coli O157: H7 resulting in a dark purple to magenta coloured moiety. E. coli forms bluish green coloured colonies. Tryptone and yeast extract provides carbonaceous, nitrogenous and growth nutrients. Addition of HiCrome™ EC O157:H7 Selective Supplement (FD187) makes the medium selective (3). Potassium tellurite selectively inhibits Aeromonas and Providencia species. Novobiocin inhibits gram-positive bacteria. Sodium lauryl sulphate helps to inhibit the accompanying gram-positive flora.
Enterohaemorragic E. coli strains are also termed as verocytotoxinproducing E.coli (VTEC/ EHEC). Although many different serotypes of Escherichia coli are known to produce verocytotoxin (2) those of Escherichia coli O157:H7 and O157:H are so far the common types causing human infections. O157 VTEC strains have several unusual biochemical characters that are exploited in methods for their laboratory identification. They belong to the minority of E. coli that are b-glucuronidase negative and do not ferment sorbitol or rhamnose within 24 hours. These can be isolated from faecal specimens by plating on media containing D-sorbitol instead of lactose. HiCrome™ EC O157:H7 Selective Agar Base, Modified is based on the formulation described by Rappaport and Henigh (1). The medium contains sorbitol and a proprietary chromogenic mixture instead of lactose and indicator dyes respectively. The chromogenic substrate is specifically and selectively cleaved by Escherichia coli O157: H7 resulting in a dark purple to magenta coloured moiety. E. coli forms bluish green coloured colonies. Tryptone and yeast extract provides carbonaceous, nitrogenous and growth nutrients. Addition of HiCrome™ EC O157:H7 Selective Supplement (FD187) makes the medium selective (3). Potassium tellurite selectively inhibits Aeromonas and Providencia species. Novobiocin inhibits gram-positive bacteria. Sodium lauryl sulphate helps to inhibit the accompanying gram-positive flora.
原理與解釋
腸出血性大腸桿菌菌株也稱為產生verocytotoxin的大腸桿菌（VTEC / EHEC）。雖然已知許多不同的大腸桿菌血清型產生verocytotoxin（2）但迄今為止大腸桿菌O157：H7和O157：H的血清型是引起人類感染的常見類型。 O157 VTEC菌株具有幾種不尋常的生化特徵，可用於實驗室鑑定方法。它們屬於β-葡萄醣醛酸酶陰性的大腸桿菌的少數，並且在24小時內不發酵山梨糖醇或鼠李糖。這些可以通過在含有D-山梨糖醇而不是乳糖的培養基上進行平板接種而從糞便標本中分離出來。 HiCrome™EC O157：H7選擇性瓊脂基質，改性基於Rappaport和Henigh（1）描述的配方。該培養基含有山梨糖醇和專有的顯色混合物，分別代替乳糖和指示劑染料。顯色底物被大腸桿菌O157：H7特異性和選擇性地切割，產生深紫色至品紅色部分。大腸桿菌形成藍綠色的菌落。 胰蛋白腖和酵母提取物提供碳質，含氮和生長營養素。添加HiCrome™EC O157：H7選擇性補充劑（FD187）使培養基具有選擇性（3）。亞碲酸鉀選擇性地抑制氣單胞菌和普羅威登斯菌種。新生黴素抑制革蘭氏陽性細菌。十二烷基硫酸鈉有助於抑制伴隨的革蘭氏陽性菌群。
腸出血性大腸桿菌菌株也稱為產生verocytotoxin的大腸桿菌（VTEC / EHEC）。雖然已知許多不同的大腸桿菌血清型產生verocytotoxin（2）但迄今為止大腸桿菌O157：H7和O157：H的血清型是引起人類感染的常見類型。 O157 VTEC菌株具有幾種不尋常的生化特徵，可用於實驗室鑑定方法。它們屬於β-葡萄醣醛酸酶陰性的大腸桿菌的少數，並且在24小時內不發酵山梨糖醇或鼠李糖。這些可以通過在含有D-山梨糖醇而不是乳糖的培養基上進行平板接種而從糞便標本中分離出來。 HiCrome™EC O157：H7選擇性瓊脂基質，改性基於Rappaport和Henigh（1）描述的配方。該培養基含有山梨糖醇和專有的顯色混合物，分別代替乳糖和指示劑染料。顯色底物被大腸桿菌O157：H7特異性和選擇性地切割，產生深紫色至品紅色部分。大腸桿菌形成藍綠色的菌落。 胰蛋白腖和酵母提取物提供碳質，含氮和生長營養素。添加HiCrome™EC O157：H7選擇性補充劑（FD187）使培養基具有選擇性（3）。亞碲酸鉀選擇性地抑制氣單胞菌和普羅威登斯菌種。新生黴素抑制革蘭氏陽性細菌。十二烷基硫酸鈉有助於抑制伴隨的革蘭氏陽性菌群。
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。