ISO 21528-1:20 17规定了一种用于检测肠杆菌科细菌的富集方法。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。 此方法适用 -当预期所寻找的微生物需要通过富集复苏时，以及 -当所寻求的数量预期低于每毫升或每克供试品100个时。 ISO 21528-1:20 17的适用性受到该方法对很大程度可变性的敏感性的限制（参见第11条）。 注:计数可以通过在液体培养基中孵育后计算最可能数（MPN）来进行。见附件A。

ISO 21528-1:2017 specifies a method, with enrichment, for the detection 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 method is applicable - when the microorganisms sought are expected to need resuscitation by enrichment, and - when the number sought is expected to be below 100 per millilitre or per gram of test sample. A limitation on the applicability of ISO 21528-1:2017 is imposed by the susceptibility of the method to a large degree of variability (see Clause 11). NOTE Enumeration can be carried out by calculation of the most probable number (MPN) after incubation in liquid medium. See Annex A.