IDG研发出O157:H7大肠杆菌免疫磁性分离方法

 
一种新开发的免疫磁性分离方法，使用特异性发光底物，能够提供高度敏感的O157:H7大肠杆菌分离解决方案。

这种新方法叫做Captivate O157，使用特异性的抗体包被磁珠，用于分离药物、食品、动物饲料、饮料和环境样品中的O157:H7大肠杆菌。这种细菌是一种十分重要的动物来源的食物传播的病原菌。主要与自限性的腹泻有关，也能够导致严重的疾病。传统分离方法会导致假阴性结果，主要是由于O157:H7菌株的竞争性菌株的干扰。

Captivate O157是由国际诊断集团有限公司(IDG, Bury, UK)研制开发的。推荐的方案使用了胰化蛋白胨大豆肉汤(MTSB)进行富集，然后使用Captivate分离，在山梨糖MacConkey琼脂上传代培养O157磁珠复合物，添加头孢克肟和亚碲酸钾。O157:H7大肠杆菌在培养基上呈现出半透明菌落。然后使用乳胶凝集试剂盒或者合适的抗血清进一步确证。
 
Immunomagnetic Method Helps Isolate E Coli
 
A combination of a newly developed immunomagnetic separation method with a specific chromogenic substrate medium provides a highly sensitive solution for the isolation of Escherichia coli O157:H7.

The new method, called Captivate O157, uses specific antibody-coated magnetic beads for the isolation of E coli O157:H7 from pharmaceutical, food, animal feed, beverage, or environmental samples. This strain is one of the most important food-borne pathogens of animal origin. Associated primarily with self-limiting diarrhea, it can also lead to much more serious conditions. Conventional isolation methods can give rise to false-negative results due to the problem of competing flora obscuring E coli O157:H7 colonies.

Captivate O157 was developed by International Diagnostics Group Ltd. (IDG, Bury, UK). The recommended protocol employs enrichment in modified tryptone soy broth (MTSB), followed by separation with Captivate prior to sub-culture of the O157-bead complex on sorbitol MacConkey agar, supplemented with cefixime and potassium tellurite. E coli O157:H7 appear as pale translucent colonies on this medium. Their identity can be confirmed using latex agglutination kits or appropriate antisera.