Ushiyama Masashi, Iwasaki Mihoko
Chisso Corp., Yokohama Research Center, 5-1 Ohkawa, Kanazawa-ku, Yokohama 236-8605, Japan.
J AOAC Int. 2010 Jan-Feb;93(1):163-83.
The Sanita-kun E. coli & Coliform sheet medium consists of a transparent cover film, an adhesive sheet, a layer of nonwoven fabric, and a water-soluble compound film, including a culture medium formula for the enumeration of total coliforms and differentiation of Escherichia coli. The Sanita-kun E. coli & Coliform sheet is a chromogenic medium and contains X-Gal, which is hydrolyzed by beta-galactosidase from coliforms to produce a visible blue dye and Salmon-glucuronic acid, which is hydrolyzed by beta-glucuronidase from E. coli to produce a red-purple dye. It is easy to distinguish the difference between E. coli and coliform (other than E. coli) colonies. Total coliforms and E. coli can be enumerated by incubating the sheet medium at 35 + 1 degrees C for 21-24 h without further confirmation. The Sanita-kun E. coli & Coliform sheets were validated as a medium for the enumeration of E. coli and total coliform in meats and meat products using processed meat and two types of raw and frozen meats using stomacher and blender homogenization. In the stomacher homogenization, all 100 samples showed no significant difference between Sanita-kun sheet and AOAC Method 966.24. The linear correlation coefficients (r2) were calculated as 0.90 (coliform) and 0.79 (E. coli). In the blender homogenization, out of 100 samples tested, 99 showed no significant difference between Sanita-kun sheet and AOAC Method 966.24, but the count of total coliforms of Sanita-kun in one sample of uninoculated raw beef was significantly higher than that obtained by AOAC Method 966.24. The linear r2 values were calculated as 0.84 (coliform) and 0.86 (E. coli). The inclusivity and exclusivity study indicated an inclusivity rate of 100% and an exclusivity rate of 95.4%. The sensitivity study showed positive results when the homogenate or dilution contained 3 CFU/mL of coliform or E. coli. The performance of four different lots of the sheets was equivalent, and suggested no change of the performance at least for 3 years at 2-15 degrees C. The Sanita-kun E. coli & Coliform sheet medium has been granted Performance Tested Method status.
“卫生君”大肠杆菌及大肠菌群片状培养基由透明覆盖膜、粘贴片、一层无纺布和水溶性复合膜组成，包含用于总大肠菌群计数及大肠杆菌鉴别分型的培养基配方。“卫生君”大肠杆菌及大肠菌群片是一种显色培养基，含有X-Gal，它可被大肠菌群中的β-半乳糖苷酶水解产生可见的蓝色染料，以及沙门氏菌葡萄糖醛酸，它可被大肠杆菌中的β-葡萄糖醛酸酶水解产生红紫色染料。很容易区分大肠杆菌和大肠菌群（除大肠杆菌外）菌落之间的差异。通过将片状培养基在35±1℃下培养21 - 24小时，无需进一步确认即可对总大肠菌群和大肠杆菌进行计数。使用加工肉以及两种生的冷冻肉，通过均质器和搅拌器匀浆，验证了“卫生君”大肠杆菌及大肠菌群片作为肉类和肉制品中大肠杆菌和总大肠菌群计数培养基的有效性。在均质器匀浆中，所有100个样品在“卫生君”片和AOAC方法966.24之间均无显著差异。线性相关系数（r2）计算为0.90（大肠菌群）和0.79（大肠杆菌）。在搅拌器匀浆中，在测试的100个样品中，99个在“卫生君”片和AOAC方法966.24之间无显著差异，但在一个未接种的生牛肉样品中，“卫生君”总大肠菌群计数显著高于AOAC方法966.24获得的计数。线性r2值计算为0.84（大肠菌群）和0.86（大肠杆菌）。包含性和排他性研究表明包含率为100%，排他率为95.4%。敏感性研究表明，当匀浆或稀释液中含有3 CFU/mL的大肠菌群或大肠杆菌时，结果为阳性。四个不同批次的片性能相当，表明在2 - 15℃下至少3年内性能无变化。“卫生君”大肠杆菌及大肠菌群片状培养基已获得性能验证方法地位。
