| 产品名称： | 李斯特菌UVM肉汤; UVM培养基; UVM李斯特菌增菌肉汤 |
|---|---|
| 英文名称: | UVM Modified Listeria Enrichment Broth; Modified UVM Medium; University of Vermont Modification Medium |
| 培养基类型: | 选择培养基 |
| 级别: | for microbiology |
| 品牌: | ELITE-MEDIA |
| 产品目录号: | M722-01、M722-02 |
| 产品规格: | 250g、500g 选择性添加剂需另购 |
| 保存条件: | 密封，阴凉干燥处保存。制备好的基础培养基2 - 8°C避光保存可达3个月。 |
| 产品外观: | 麦秸色均一粉末。 |
| 溶液颜色与澄清度: | 琥珀色透明溶液。 |
| 注意事项: | 避免摄入、呼入、皮肤接触。 |
| 相关产品: | Listeria UVM II Supplement |
产品描述：
李斯特菌增菌肉汤UVM培养基（UVM Modified Listeria Enrichment Broth）简称改良UVM肉汤，是单增李斯特菌选择性液体培养基，是美国农业部采用的“两步选择性增菌法”所使用的培养基。UVM培养基用于分离肉类食品和临床样品中的李斯 特菌。李斯特菌是革兰氏阳性、不产芽孢的短杆菌。在李斯特菌中仅有单增李斯特菌是食物传播的人类致病菌。单增李斯特菌广泛存在于未加工的食 品中,如薰肠、卷心菜色拉、巴氏消毒鲜奶等，也存在于环境中。李斯特菌能够适应pH5.0~9.6，在超出这个pH范围的食品中也能存活。 本配方是《细菌学分析手册》、美国食品药品监督局（FDA）、美国农业部（USDA）采用的标准配方。
工作原理
改良UVM培养基（University of Vermont Modification Medium）配方中含有牛肉提取物、酵母提取物 、胰酪蛋白胨、动物组织蛋白胨，这些成分为李斯特菌的生长提供氮源、维生素和矿物质。氯化钠维持渗透压平衡，磷酸盐是酸碱缓冲系统。 萘啶酮酸是革兰氏阴性菌抑制剂，主要抑制大肠埃希氏菌、痢疾杆菌和变形杆菌的生长。盐酸吖啶黄是革兰氏阳性菌抑制剂。用途：
改良UVM肉汤被推荐用于热损伤李斯特菌的初步选择性增菌。两步选择性增菌法仅需要3~4天就可以初步鉴定单增李斯特菌，而且极大提高了检出率。
要注意的是UVM培养基含有高盐分，可能会减低DNA探针法的检测率。
配方与配制方法
| 培养基成分： | 含量：/L |
|---|---|
| 牛肉提取物 | 5.0 g |
| 月示蛋白胨 | 5.0 g |
| 酵母提取物 | 5.0 g |
| 胰酪蛋白胨 | 5.0 g |
| 氯化钠 | 20.0 g |
| 磷酸二氢钾 | 1.35 g |
| 磷酸氢二钠 | 12.0 g |
| 七叶苷 | 1.0 g |
| pH |
7.2± 0.2 |
李斯特菌UVM选择性添加剂
| 2%萘啶酮酸溶液 | 1.0 ml |
|---|---|
| 吖啶黄单盐酸盐 | 12 mg （二次选择性增菌使用量为25 mg） |
配制方法：
1. 称取54.4g本品，用1000ml去离子水重悬浸泡10min。
2. 搅拌使其全部溶解。
3. 121°C高温灭菌15min。
4. 冷却至50°C以下时加入1ml无菌2%萘啶酮酸溶液和1ml无菌吖啶黄单盐酸盐溶液。该两种补充剂在Biofeng均有售。
实验方法
UVM培养基的接种量为1:10，30°C 有氧条件下培养20–26h，检查结果。环境中李斯特菌的检测——培养基法
Testing Methodology for Listeria species or L. monocytogenes in Environmental Samples一. 样品处理
Aseptically pour 9-10 ml of sterile Dey-Engley (D/E) broth into the bag to hydrate the swabs and sponges. Close the bag and evenly moisten the swabs or sponges by hand message. Position the swab/sponge so that the handle is sticking out of the bag and close the bag around the handle. Through the bag, squeeze the excess broth gently out of the swab/sponge. Carefully take the swab/sponge out of the bag by grasping the handle and swab the area selected using firm and even pressure. Swab/sponge vertically (approximately 10 times); then flip the swab/sponge and use the other side to swab/sponge horizontally (approximately 10 times); then swab/sponge diagonally, using the same surface side as you used for horizontal (approximately 10 times). Swab areas of food contact or environmental surface at least 1” x 1 ” in size (1’ x 1’ for sponges or according to manufacturer’s instructions). Open the bag and insert the swab/sponge portion into the bag. Break the handle and close the bag according to manufacturer’s instructions. For shipping samples to labs, the samples need to be placed in a pre-chilled shipping container by placing pre-frozen gel packs at the bottom with a cool board placed on top of them. The samples will then be placed in the container followed by another layer of foam plugs or cool board. The samples should be shipped on the same day. When this is not possible, the samples should be stored refrigerated while waiting to be shipped. Contact the appropriate laboratory in advance to inform the shipment and expected arrival of the samples.
二. 初步增菌
Add 225 ± 5 ml UVM broth to each bagged single swab/sponge sample. Stomach for 2 ± 0.2 min, or briefly massage each sample by hand to expel the collection broth into the UVM broth. Incubate at 30 ± 2°C for 20 - 26 h.
三. 二次增菌
1. Transfer 0.1 ± 0.02 ml of the UVM enrichment to 10 ± 0.5 ml of Fraser broth (FB) containing appropriate supplements. Incubate inoculated FB tubes at 35 ± 2°C for 26 ± 2 h.
2. On the same day of transferring to FB, streak a loopful or a drop approximating 0.1 ml of the UVM over the surface of a MOX plate. Incubate the MOX at 35 ± 2°C for 26 ± 2 h.
