PathogenDx, 9375 E. Shea Blvd. Ste. 100, Scottsdale, AZ 85260, USA.
J AOAC Int. 2022 Sep 6;105(5):1390-1407. doi: 10.1093/jaoacint/qsac040.
The PathogenDx EnviroX-F uses microarray technology to simultaneously detect Listeria species, Listeria monocytogenes, and Salmonella species from environmental samples without the need for enrichment.
The validation study included a matrix study of four matrices (stainless steel, plastic, rubber, and sealed concrete) comparing the PathogenDx EnviroX-F assay to the US Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) Chapter 10, "Detection of L. monocytogenes in Foods and Environmental Samples, and Enumeration of L. monocytogenes in Foods" (revised March 2017), and FDA BAM Chapter 5,"Salmonella" (revised February 2020). Other required Performance Tested MethodSM parameters evaluated included: inclusivity and exclusivity, robustness, instrument variation, and product consistency and stability.
The PathogenDx EnviroX-F assay was evaluated with 30 unpaired replicate surface areas for each environmental surface. The candidate method was evaluated without an enrichment step.
In the inclusivity and exclusivity study 50 out of 50 Listeria isolates were detected, 50 out of 50 L. monocytogenes strains were detected, 108 out of 108 Salmonella strains were detected, and 95 out of 95 exclusivity strains were correctly excluded. In the matrix study, the PathogenDx EnviroX-F assay showed no significant differences between confirmed results or between candidate and reference method results for 4" × 4" environmental surface areas for each matrix.
The PathogenDx EnviroX-F assay is an effective method for the qualitative detection of Listeria spp., L. monocytogenes, and Salmonella spp. from environmental surface swabs.
The PathogenDx EnviroX-F assay will be the first PTM-approved multiplex assay for Listeria spp., L. monocytogenes, and Salmonella without the need for an environment step.
PathogenDx EnviroX-F 使用微阵列技术，无需富集，即可同时从环境样本中检测李斯特菌属、单核细胞增生李斯特菌和沙门氏菌属。
验证研究包括对不锈钢、塑料、橡胶和密封混凝土四种基质的基质研究，将 PathogenDx EnviroX-F 检测法与美国食品和药物管理局（FDA）《微生物分析手册》（BAM）第 10 章“食品和环境样本中单增李斯特菌的检测及食品中单增李斯特菌的计数”（2017 年 3 月修订）和 FDA BAM 第 5 章“沙门氏菌”（2020 年 2 月修订）进行比较。评估的其他必需的经过性能测试的方法（PTM）参数包括：包容性和排他性、稳健性、仪器变异以及产品一致性和稳定性。
对每种环境表面的 30 个未配对的重复表面面积进行了 PathogenDx EnviroX-F 检测法评估。候选方法未经富集步骤进行评估。
在包容性和排他性研究中，50 株李斯特菌分离株全部检出，50 株单核细胞增生李斯特菌全部检出，108 株沙门氏菌全部检出，95 株排他性菌株全部正确排除。在基质研究中，PathogenDx EnviroX-F 检测法在确认结果或 4"×4" 环境表面的候选和参考方法结果之间没有显著差异。
PathogenDx EnviroX-F 检测法是一种从环境表面拭子中定性检测李斯特菌属、单核细胞增生李斯特菌和沙门氏菌属的有效方法。
PathogenDx EnviroX-F 检测法将是首个经 PTM 批准的无需环境步骤即可同时检测李斯特菌属、单核细胞增生李斯特菌和沙门氏菌的多重检测方法。
