| 產品名稱： | 李斯特菌UVM肉湯; UVM培養基; UVM李斯特菌增菌肉湯 |
|---|---|
| 英文名稱: | UVM Modified Listeria Enrichment Broth; Modified UVM Medium; University of Vermont Modification Medium |
| 培養基類型: | 選擇培養基 |
| 級別: | for microbiology |
| 品牌: | ELITE-MEDIA |
| 產品目錄號: | M722-01、M722-02 |
| 產品規格: | 250g、500g 選擇性添加劑需另購 |
| 保存條件: | 密封，陰涼干燥處保存。制備好的基礎培養基2 - 8°C避光保存可達3個月。 |
| 產品外觀: | 麥秸色均一粉末。 |
| 溶液顏色與澄清度: | 琥珀色透明溶液。 |
| 注意事項: | 避免攝入、呼入、皮膚接觸。 |
| 相關產品: | Listeria UVM II Supplement |
產品描述：
李斯特菌增菌肉湯UVM培養基（UVM Modified Listeria Enrichment Broth）簡稱改良UVM肉湯，是單增李斯特菌選擇性液體培養基，是美國農業部采用的“兩步選擇性增菌法”所使用的培養基。UVM培養基用于分離肉類食品和臨床樣品中的李斯 特菌。李斯特菌是革蘭氏陽性、不產芽孢的短桿菌。在李斯特菌中僅有單增李斯特菌是食物傳播的人類致病菌。單增李斯特菌廣泛存在于未加工的食 品中,如薰腸、卷心菜色拉、巴氏消毒鮮奶等，也存在于環境中。李斯特菌能夠適應pH5.0~9.6，在超出這個pH范圍的食品中也能存活。 本配方是《細菌學分析手冊》、美國食品藥品監督局（FDA）、美國農業部（USDA）采用的標準配方。
工作原理
改良UVM培養基（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、動物組織蛋白胨，這些成分為李斯特菌的生長提供氮源、維生素和礦物質。氯化鈉維持滲透壓平衡，磷酸鹽是酸堿緩沖系統。 萘啶酮酸是革蘭氏陰性菌抑制劑，主要抑制大腸埃希氏菌、痢疾桿菌和變形桿菌的生長。鹽酸吖啶黃是革蘭氏陽性菌抑制劑。用途：
改良UVM肉湯被推薦用于熱損傷李斯特菌的初步選擇性增菌。兩步選擇性增菌法僅需要3~4天就可以初步鑒定單增李斯特菌，而且極大提高了檢出率。
要注意的是UVM培養基含有高鹽分，可能會減低DNA探針法的檢測率。
配方與配制方法
| 培養基成分： | 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 |
| 氯化鈉 | 20.0 g |
| 磷酸二氫鉀 | 1.35 g |
| 磷酸氫二鈉 | 12.0 g |
| 七葉苷 | 1.0 g |
| pH |
7.2± 0.2 |
李斯特菌UVM選擇性添加劑
| 2%萘啶酮酸溶液 | 1.0 ml |
|---|---|
| 吖啶黃單鹽酸鹽 | 12 mg （二次選擇性增菌使用量為25 mg） |
配制方法：
1. 稱取54.4g本品，用1000ml去離子水重懸浸泡10min。
2. 攪拌使其全部溶解。
3. 121°C高溫滅菌15min。
4. 冷卻至50°C以下時加入1ml無菌2%萘啶酮酸溶液和1ml無菌吖啶黃單鹽酸鹽溶液。該兩種補充劑在Biofeng均有售。
實驗方法
UVM培養基的接種量為1:10，30°C 有氧條件下培養20–26h，檢查結果。環境中李斯特菌的檢測——培養基法
Testing Methodology for Listeria species or L. monocytogenes in Environmental Samples一. 樣品處理
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.