ISO 21528-2:20 17规定了肠杆菌科的计数方法。它适用于 -拟供人食用及喂养动物的产品，及 -初级生产、食品生产和食品处理领域的环境样本。 当预期寻找的菌落数量超过100个/毫升或/克供试品时，预期使用该技术。 ISO 21528中包含的最可能数（MPN）技术？当预期所寻求的数量低于100/毫升或每克测试样品时，通常使用1。

ISO 21528-2:2017 specifies a method for the enumeration of Enterobacteriaceae. It is applicable to - products intended for human consumption and the feeding of animals, and - environmental samples in the area of primary production, food production and food handling. This technique is intended to be used when the number of colonies sought is expected to be more than 100 per millilitre or per gram of the test sample. The most probable number (MPN) technique, as included in ISO 21528？1, is generally used when the number sought is expected to be below 100 per millilitre or per gram of test sample.