食物链的微生物学. 新鲜绿叶蔬菜和浆果类水果中隐孢子虫和贾第鞭毛虫的检测和计数

[中文适用范围]： 本国际标准规定了适用于本文所述的新鲜绿叶蔬菜和浆果类食品中隐孢子虫卵囊和贾第鞭毛虫包囊的检测和计数的方法。 通过适当的控制，它也可适用于其他新鲜农产品的检查。 显微镜描述适用于隐孢子虫属。 大小范围内的卵囊和十二指肠贾第鞭毛虫包囊，其中包括已知对人类致病的物种（隐孢子虫）或组合（贾第鞭毛虫）。 该方法不包括任何分子分析，因此不适用于隐孢子虫卵囊和贾第鞭毛虫包囊的物种或基因型/组合的测定。 该方法将检测已知对人类致病的所有物种和基因型/组合以及其他对人类无致病性的物种和基因型/组合。 为了进一步鉴定，需要进行分子分型测定。 然而，如果将过程阳性对照掺入样品中，则无法可靠地执行这些操作，因为分子分型测定的结果将被混淆。 该方法不允许测定可能存在的任何隐孢子虫卵囊和贾第鞭毛虫包囊的活力或感染性。 [外文原描述]： ISO 18744:2016 specifies a method that is applicable for the detection and enumeration of Cryptosporidium oocysts and Giardia cysts on or in food products that are described herein as fresh leafy green vegetables and berry fruits. With suitable controls, it may also be applicable for the examination of other fresh produce. The microscopy descriptions are for Cryptosporidium spp. oocysts and Giardia duodenalis cysts of size ranges which include those species ( Cryptosporidium ) or assemblages ( Giardia ) known to be pathogenic to humans. This method does not include any molecular analysis and therefore is not suitable for the determination of the species or genotypes/assemblages of Cryptosporidium oocysts and Giardia cysts. The method will detect all species and genotypes/assemblages that are known to be pathogenic for humans and also others that are not. For further identification, molecular typing assays are required. However, these cannot be reliably performed if process positive controls have been spiked into the samples, as the result of molecular typing assays will be obfuscated. This method does not allow the determination of viability or infectivity of any Cryptosporidium oocysts and Giardia cysts which may be present.