Background Soleris® E. coli is an automated, growth-based method for detection and semi-quantitative determination of Escherichia coli in foods. The method can be used in dilute-to-specification (threshold) or presence/absence modes. Objective The objective of the study was to validate four modifications to the method: (1) a change in the vial detection window plug composition from agar to agarose to improve plug consistency and robustness, (2) a change in pre-enrichment incubation time for presence/absence testing from 6 h to 18–24 h, (3) a change in vial incubation temperature from 44.5 to 43.5°C, and (4) incorporation of a simple direct-from-vial confirmation test as an alternative to traditional procedures. Methods Elements of the study included inclusivity/exclusivity testing, matrix testing in comparison to the ISO 7251:2005 reference method, reagent stability/lot-to-lot consistency testing, and an independent laboratory study. Results In inclusivity testing, all 55 Escherichia coli strains tested produced positive results. In exclusivity testing, 30 of 31 strains of other bacterial species produced negative results, the sole exception being a strain of Enterobacter cloacae. In internal and independent laboratory matrix testing of mozzarella cheese, condensed milk, pasteurized liquid egg, and frozen green beans, results showed no significant differences in performance of the Soleris and reference methods with two exceptions, one in which the Soleris method produced more positive results, and one in which the reference method produced more positive results. Conclusion Performance characteristics of the modified Soleris E. coli method are consistent with those of the original validated method. Highlights The Soleris E. coli method offers improvements in ease of use and reagent robustness.

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对用于检测和确定特定食品中大肠杆菌的阈值确定的 Soleris® 大肠杆菌方法的修改验证：对 AOAC 性能测试方法 SM 101101 的 3 级修改

背景 Soleris® 大肠杆菌是一种基于生长的自动化检测和半定量测定食品中大肠杆菌的方法。该方法可用于按规格稀释（阈值）或存在/不存在模式。目的 本研究的目的是验证对该方法的四项修改：（1）将小瓶检测窗口塞组成从琼脂改为琼脂，以提高塞的一致性和稳健性，（2）改变预富集孵育时间存在/不存在测试从 6 小时到 18-24 小时，(3) 小瓶孵育温度从 44.5 到 43.5°C 的变化，以及 (4) 结合简单的直接来自小瓶的确认测试作为传统程序的替代方案. 方法 研究的要素包括包容性/排他性测试、与 ISO 7251:2005 参考方法比较的矩阵测试、试剂稳定性/批间一致性测试，以及独立的实验室研究。结果 在包容性测试中，测试的所有 55 株大肠杆菌都产生了阳性结果。在排他性测试中，31 种其他细菌菌株中有 30 种产生了阴性结果，唯一的例外是阴沟肠杆菌菌株。在对马苏里拉奶酪、炼乳、巴氏杀菌蛋液和冷冻青豆的内部和独立实验室矩阵测试中，结果显示 Soleris 和参考方法的性能没有显着差异，但有两个例外，其中一个 Soleris 方法产生了更积极的结果，以及参考方法产生更积极结果的方法。结论改良 Soleris E 的性能特点。大肠杆菌方法与原验证方法一致。亮点 Soleris 大肠杆菌方法提高了易用性和试剂稳定性。