| 产品名称： | 改良双歧杆菌琼脂 |
|---|---|
| 英文名称： | Bifidobacterium Agar, Modified |
| 培养基类型： | 非选择性培养基 |
| 级别： | for microbiology |
| 品牌： | ELITE-MEDIA（艾礼培养基） |
| 产品目录号： | M100-01、M100-02、M100-03 |
| 产品规格： | 250g、500g（添加剂需另购）、20个平板/包 |
| 产品外观： | 麦秸色均一粉末。 |
| 灭菌后颜色与澄清度： | 浅琥珀色透明至微不透明凝胶。 |
| 保存条件： | 密封，2-25°C保存。制备好的培养基2-8°C避光保存。 |
| 注意事项： | 避免摄入、吸入、皮肤接触。 |
| 相关产品： | -- |
产品描述：
改良双歧杆菌琼脂(Bifidobacterium Agar, Modified)是选择性培养基，用于从粪便样本中分离双歧杆菌。本培养基配方与BD™ Bifidobacterium Agar, Modified相同。工作原理
双歧杆菌菌种是革兰氏阳性菌、厌氧、分支或多形性杆菌。双歧杆菌可以从多种材料中分离得到，如人和动物粪便、污水和口腔。双歧杆菌在人体内主要栖息于大肠，与其它常见肠道菌一道构成大肠菌群的主要部分，健康的成人粪便中菌密度可以达到109 -1011 每克。当正常菌丛的构成被打乱后，即双歧杆菌被肠杆菌、假单胞菌或酵母菌超过时，会导致慢性腹泻和其它肠道和消化紊乱。由于双歧杆菌和乳杆菌的低致病性，被越来越多用作益生菌，改善肠道菌丛构成。另外，益生菌也被用于某些改善肠外疾病，如阴道炎、幽门螺杆菌感染和囊性纤维化。几种培养基设计用于选择性分离双歧杆菌。鉴于双歧杆菌包含超过25种已知菌种，在抗菌剂和其它抑制剂耐受性方面具有相当的异质性，单一培养基同时做到高回收率和高选择性是很难的。多个评估研究表明，改良双歧杆菌培养基比其它双歧杆菌选择培养基的回收率高。改良双歧杆菌琼脂衍生于哥伦比亚琼脂基础，加入了丙酸，pH降低。丙酸能够抑制真菌和除双歧杆菌外其它细菌，如肠道拟杆菌和肠杆菌。低pH能够进一步抑制在粪便中占主要地位的微生物，如拟杆菌和真细菌。半胱氨酸是还原剂。乳果糖是双歧杆菌优先利用的糖类，葡萄糖作为通用型糖类，用于加速起始生长速度。核黄素是很多双歧杆菌必需的维生素。pH升高至5.5，以改善凝胶强度和有利于双歧杆菌的更好生长。
用途：
改良双歧杆菌琼脂用于从粪便样本中分离双歧杆菌。配方与配制方法
| 成分 | g/L |
| 哥伦比亚琼脂基础 | 42.5 |
| 葡萄糖 | 2.5 |
| 乳果糖 | 2.5 |
| 半胱氨酸盐酸盐 | 0.5 |
| 核黄素 | 0.01 |
| 丙酸 | 5.0 ml |
| pH 5.5 +/- 0.2 |
配制方法：
1. 称取48g本产品，用1000ml去离子水重悬。
2. 加热煮沸至完全溶解。
3. 121°C灭菌15min。
4. 冷却至45-50°C，加入5ml丙酸，混合均匀后倒平板。酸性会使琼脂变软。
实验方法
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.
结果与分析
35-37°C培养2-3天，标准菌株在改良双歧杆菌琼脂中生长情况如下：标准菌株 生长情况 菌落特征 长双歧杆菌DSM20219 良好 乳白色菌落，有酸味 长双歧杆菌DSM20082 良好 乳白色菌落，有酸味 脆弱类拟杆菌ATCC25285 部分至完全被抑制 嗜酸乳杆菌ATCC314 部分至完全被抑制 大肠埃希氏菌ATCC25922 部分至完全被抑制
