Rijpens N, Herman L, Vereecken F, Jannes G, De Smedt J, De Zutter L
Agricultural Research Centre, Department for Animal Product Quality, Melle, Belgium.
Int J Food Microbiol. 1999 Jan 12;46(1):37-44. doi: 10.1016/s0168-1605(98)00171-8.
The rapid detection of an average of 5.9 stressed Salmonella cells in 25 g of food product using immunomagnetic separation (IMS) and PCR is described. For pasteurised egg yolk, egg yolk powder, ice-cream, whole egg, egg white and cheeses made from pasteurised milk PCR was applied after 16 h of preenrichment in buffered peptone water (BPW) using IMS and alkaline lysis as sample preparation method. For whole egg and egg white the BPW was supplemented with iron. For milk powder, and raw milk cheeses, the 16-h preenrichment in BPW was followed by IMS and a 4-h enrichment in Rappaport-Vassiliadis broth. In the latter case, PCR was applied on the enrichment medium after centrifugation and alkaline lysis. For PCR the primers ST11 and ST15 (Aabo et al., 1993) producing a fragment of 429 bp were used. An internal PCR control, designed to be co-amplified with the target DNA using the same primers but producing a smaller fragment of 240 bp, was used.
本文描述了使用免疫磁珠分离（IMS）和聚合酶链反应（PCR）在25克食品中快速检测平均5.9个应激沙门氏菌细胞的方法。对于巴氏杀菌蛋黄、蛋黄粉、冰淇淋、全蛋、蛋清以及由巴氏杀菌牛奶制成的奶酪，采用IMS和碱性裂解作为样品制备方法，在缓冲蛋白胨水（BPW）中预富集16小时后进行PCR检测。对于全蛋和蛋清，BPW中添加了铁。对于奶粉和生牛奶奶酪，在BPW中进行16小时预富集后进行IMS，然后在Rappaport-Vassiliadis肉汤中富集4小时。在后一种情况下，离心和碱性裂解后在富集培养基上进行PCR。PCR使用产生429 bp片段的引物ST11和ST15（Aabo等人，1993年）。使用了一个内部PCR对照，设计为使用相同引物与目标DNA共同扩增，但产生240 bp的较小片段。
