用于食品中大肠杆菌O157检测的免疫磁分离方法中所使用的分离介质的优化。

The optimization of isolation media used in immunomagnetic separation methods for the detection of Escherichia coli O157 in foods.

作者信息

Ogden I D, Hepburn N F, MacRae M

机构信息

Applied Food Microbiology Group, Department of Medical Microbiology, University of Aberdeen, UK.

出版信息

J Appl Microbiol. 2001 Aug;91(2):373-9. doi: 10.1046/j.1365-2672.2001.01397.x.

DOI:10.1046/j.1365-2672.2001.01397.x

PMID:11473603

Abstract

AIMS

To compare media used in immunomagnetic separation (IMS) techniques for the isolation of Escherichia coli O157 from food.

METHODS AND RESULTS

Foods, both naturally contaminated and spiked, with low numbers (< 1 g(-1)) of stressed E. coli O157 were enriched in media based on buffered peptone water (BPW), tryptone soya and EC broths incubated at 30, 37, 40 and 42 degrees C. Following immunomagnetic separation, beads were plated on a range of selective agars.

CONCLUSION

BPW supplemented with vancomycin (8 mg l(-1)) incubated at 42 degrees C, followed by IMS and subsequent plating of immunobeads onto cefixime tellurite sorbitol MacConkey agar plus either Rainbow or CHROMagar agars, proved optimum for the recovery of spiked, stressed E. coli O157 in minced beef, cheese, apple juice and pepperoni. The same protocol was optimum for recovery from naturally-contaminated minced beef and cheese.

SIGNIFICANCE AND IMPACT OF THE STUDY

The optimum protocol would increase isolation rates of E. coli O157 from foods.

摘要

目的

比较免疫磁珠分离（IMS）技术中用于从食品中分离大肠杆菌O157的培养基。

方法与结果

将自然污染和接种有少量（<1 g⁻¹）应激大肠杆菌O157的食品，在基于缓冲蛋白胨水（BPW）、胰蛋白胨大豆肉汤和EC肉汤的培养基中，于30、37、40和42℃下进行增菌培养。免疫磁珠分离后，将磁珠接种在一系列选择性琼脂平板上。

结论

在42℃下培养添加了万古霉素（8 mg l⁻¹）的BPW，随后进行免疫磁珠分离，并将免疫磁珠接种到头孢克肟亚碲酸盐山梨醇麦康凯琼脂加彩虹琼脂或CHROMagar琼脂上，被证明是从碎牛肉、奶酪、苹果汁和意大利辣香肠中回收接种的应激大肠杆菌O157的最佳方法。相同方案对于从自然污染的碎牛肉和奶酪中回收也是最佳的。