| 產品名稱： | 改良雙歧桿菌瓊脂 |
|---|---|
| 英文名稱： | Bifidobacterium Agar, Modified |
| 培養基類型： | 非選擇性培養基 |
| 級別： | for microbiology |
| 品牌： | ELITE-MEDIA（艾禮培養基） |
| 產品目錄號： | M100-01、M100-02、M100-03 |
| 產品規格： | 250g、500g（添加劑需另購）、20個平板/包 |
| 產品外觀： | 麥秸色均一粉末。 |
| 滅菌后顏色與澄清度： | 淺琥珀色透明至微不透明凝膠。 |
| 保存條件： | 密封，2-25°C保存。制備好的培養基2-8°C避光保存。 |
| 注意事項： | 避免攝入、吸入、皮膚接觸。 |
| 相關產品： | -- |
產品描述：
改良雙歧桿菌瓊脂(Bifidobacterium Agar, Modified)是選擇性培養基，用于從糞便樣本中分離雙歧桿菌。本培養基配方與BD™ Bifidobacterium Agar, Modified相同。工作原理
雙歧桿菌菌種是革蘭氏陽性菌、厭氧、分支或多形性桿菌。雙歧桿菌可以從多種材料中分離得到，如人和動物糞便、污水和口腔。雙歧桿菌在人體內主要棲息于大腸，與其它常見腸道菌一道構成大腸菌群的主要部分，健康的成人糞便中菌密度可以達到109 -1011 每克。當正常菌叢的構成被打亂后，即雙歧桿菌被腸桿菌、假單胞菌或酵母菌超過時，會導致慢性腹瀉和其它腸道和消化紊亂。由于雙歧桿菌和乳桿菌的低致病性，被越來越多用作益生菌，改善腸道菌叢構成。另外，益生菌也被用于某些改善腸外疾病，如陰道炎、幽門螺桿菌感染和囊性纖維化。幾種培養基設計用于選擇性分離雙歧桿菌。鑒于雙歧桿菌包含超過25種已知菌種，在抗菌劑和其它抑制劑耐受性方面具有相當的異質性，單一培養基同時做到高回收率和高選擇性是很難的。多個評估研究表明，改良雙歧桿菌培養基比其它雙歧桿菌選擇培養基的回收率高。改良雙歧桿菌瓊脂衍生于哥倫比亞瓊脂基礎，加入了丙酸，pH降低。丙酸能夠抑制真菌和除雙歧桿菌外其它細菌，如腸道擬桿菌和腸桿菌。低pH能夠進一步抑制在糞便中占主要地位的微生物，如擬桿菌和真細菌。半胱氨酸是還原劑。乳果糖是雙歧桿菌優先利用的糖類，葡萄糖作為通用型糖類，用于加速起始生長速度。核黃素是很多雙歧桿菌必需的維生素。pH升高至5.5，以改善凝膠強度和有利于雙歧桿菌的更好生長。
用途：
改良雙歧桿菌瓊脂用于從糞便樣本中分離雙歧桿菌。配方與配制方法
| 成分 | g/L |
| 哥倫比亞瓊脂基礎 | 42.5 |
| 葡萄糖 | 2.5 |
| 乳果糖 | 2.5 |
| 半胱氨酸鹽酸鹽 | 0.5 |
| 核黃素 | 0.01 |
| 丙酸 | 5.0 ml |
| pH 5.5 +/- 0.2 |
配制方法：
1. 稱取48g本產品，用1000ml去離子水重懸。
2. 加熱煮沸至完全溶解。
3. 121°C滅菌15min。
4. 冷卻至45-50°C，加入5ml丙酸，混合均勻后倒平板。酸性會使瓊脂變軟。
實驗方法
Specimen TypesThis medium is used for the isolation and quantitative determination of Bifidobacterium species from stool specimens of patients that suffer from chronic diarrhea and other intestinal and digestive disorders. Stool specimens (ideally 10 to 15 grams of stool) must not be older than 24 hours. The use of an anaerobic transport medium is recommended.
Test Procedure
Before use, Bifidobacterium Agar, Modified may be prereduced in an anaerobic atmosphere for at least 24 hours, kept at room temperature. This procedure may increase the viable counts of the organisms to be detected. The GasPak Anaerobic system may be used for this purpose.
For the study of the fecal flora, fresh human stool specimens should be suspended in sterile saline or anaerobic saline (saline containing 0.1 g of cystein-HCl per liter), followed by tenfold dilutions in the same suspension medium. Samples of 20 to 50 µl of the highest dilutions (e.g. 10-4 to 10-7) should be pipetted onto Bifidobacterium Agar, Modified which is then spread-inoculated and incubated anaerobically, e.g., by using the GasPak Anaerobic system.
Other media (e.g., for the determination of total counts and possibly for detection of other bacterial groups, e.g. Lactobacillus, Bacteroides, Clostridium, Enterobacteriaceae) should also be inoculated from the appropriate fecal dilutions and incubated according to the requirements of the media and the bacterial groups.
Results and Interpretation
After the incubation, plates are inspected for growth. Appropriate colonies of must be tested microscopically (Gram stains) for the presence of typical bifid, gram positive rods. Colonies may then be counted, and the number of colonies is then multiplied by the dilution factor of the sample to obtain the CFU per gram feces. Subcultures and biochemical tests must be performed for a final identification of the organisms isolated.
In the feces of healthy individuals, bifidobacteria shall be present in high counts while their absence or low counts may be a hint for intestinal disorder.
Reduced occurrence of bifidobacteria in normal flora does not imply treatment of patients with antimicrobial agents or medications other than probiotics unless specific infectious agents have been detected as the cause of the disorder.
Performance Characteristics And Limitations Of The Procedure
This medium is used for the determination of the Bifidobacterium flora in human feces. The Beerens formulation of Bifidobacterium Agar and similar media have been found to be superior to media with a higher degree of selectivity for the isolation of bifidobacteria from the human gut. There exist bifidobacteria that are extremely fastidious and do not grow sufficiently on this or other selective media. Therefore, a nonselective medium (e.g. Schaedler Agar with Vitamin K1 and 5% Sheep Blood) should be included.
Due to its low pH and the addition of propionic acid, Bifidobacterium Agar, Modified inhibits lactobacilli, Eubacterium species, clostridia, Enterobacteriaceae and many others. Inhibition may be partial or complete, depending on the organisms. If undiluted human feces are inoculated, organisms other than Bifidobacterium may grow on this medium.
Bifidobacterium Agar, modified should not be used for the isolation of Bifidobacterium species from feces of species other than man.
結果與分析
35-37°C培養2-3天，標準菌株在改良雙歧桿菌瓊脂中生長情況如下：標準菌株 生長情況 菌落特征 長雙歧桿菌DSM20219 良好 乳白色菌落，有酸味 長雙歧桿菌DSM20082 良好 乳白色菌落，有酸味 脆弱類擬桿菌ATCC25285 部分至完全被抑制 嗜酸乳桿菌ATCC314 部分至完全被抑制 大腸埃希氏菌ATCC25922 部分至完全被抑制