Clear Labs, Inc, 1559 Industrial Road, San Carlos, CA 94070, USA.
Q Laboratories, Inc, 1930 Radcliff Drive, Cincinnati, OH 45214, USA.
J AOAC Int. 2022 Feb 4;105(1):211-229. doi: 10.1093/jaoacint/qsab084.
The Clear Safety Listeria method utilizes polymerase chain reaction (PCR) amplification and targeted next-generation sequencing technology to detect Listeria species (L. monocytogenes, L. innocua, L. ivanovii, L. marthii, L. grayi, L. welshimeri, and L. seeligeri) in hot dogs and on selected environmental surfaces.
The aim was to validate the candidate method according to current AOAC guidelines.
The candidate method was compared to the reference method for hot dogs and the environmental surfaces. The method was also evaluated for inclusivity and exclusivity using 50 inclusivity strains and 30 exclusivity strains for each reported target. Product consistency and stability was tested and robustness was evaluated with changes in enrichment temperature, volume of sample treatment, and aliquot volume for PCR.
The candidate method demonstrated no statistically significant differences using the probability of detection model between candidate and reference methods or between presumptive and confirmed results for all environmental surfaces and hot dogs. Additionally, the candidate method detected all inclusivity organisms and excluded all exclusivity organisms for each reported target. Product lots were shown to be consistent and data supported the kit's shelf life. Finally, the robustness study demonstrated no statistical differences when the volume of sample or the aliquot volume for PCR was altered. Increasing the incubation temperature to 37 ± 1 °C resulted in greater recovery of L. monocytogenes as compared to 35 ± 1 °C and 30 ± 1 °C.
The Clear Safety Listeria method is statistically equivalent to the reference methods for the detection of L. monocytogenes and Listeria spp. in hot dogs and on selected environmental surfaces.
The Clear Safety Listeria method is an automated, highthroughput NGS-based method capable of detecting Listeria species in the hot dog and environmental samples within 28h.
Clear Safety Listeria 方法利用聚合酶链反应（PCR）扩增和靶向下一代测序技术来检测李斯特菌属（单核细胞增生李斯特菌、无害李斯特菌、伊氏李斯特菌、马氏李斯特菌、格氏李斯特菌、威尔士李斯特菌和西尔李斯特菌）在热狗和选定的环境表面。
根据当前的 AOAC 指南验证候选方法。
候选方法与热狗和环境表面的参考方法进行了比较。该方法还使用每个报告目标的 50 个包容性菌株和 30 个排他性菌株进行了包容性和排他性评估。对产品一致性和稳定性进行了测试，并通过改变富集温度、样品处理量和 PCR 等分样量来评估稳健性。
候选方法在使用概率检测模型时，在所有环境表面和热狗中，候选方法与参考方法之间或推定结果与确认结果之间均无统计学差异。此外，候选方法检测到每个报告目标的所有包容性生物体，并排除了所有排他性生物体。产品批次被证明是一致的，数据支持试剂盒的保质期。最后，稳健性研究表明，当改变样品量或 PCR 等分样量时，没有统计学差异。与 35°C±1°C 和 30°C±1°C 相比，将孵育温度提高到 37°C±1°C 可使单核细胞增生李斯特菌的回收率更高。
Clear Safety Listeria 方法在检测热狗和选定环境表面的单核细胞增生李斯特菌和李斯特菌属方面与参考方法在统计学上等效。
Clear Safety Listeria 方法是一种自动化、高通量的基于 NGS 的方法，能够在 28 小时内检测热狗和环境样本中的李斯特菌属。
