Laboratory Corporation of America®/MedTox, 402 County Road D West, St. Paul, MN 55112, USA.
Laboratory of America Corporation®/National Genetics Institute, 2440 Sepulveda Blvd., Suite 235, Los Angeles, CA 90064, USA.
J AOAC Int. 2021 Dec 11;104(6):1567-1579. doi: 10.1093/jaoacint/qsab037.
The PhageDx™Salmonella Assay is based on the infection of Salmonella spp. by specific bacteriophages and expression of a luciferase reporter gene. Results are generated in as little as 9.5 h for raw ground turkey and 18.5 h for milk-based powdered infant formula (PIF).
An AOAC Performance Tested MethodsSM (PTM) study was conducted to validate the PhageDx Salmonella Assay for the detection of Salmonella in 25 g raw ground turkey and 100 g PIF test portions.
The performance of the PhageDx Salmonella Assay was compared to that of the U.S. Department of Agriculture (USDA), Food Safety and Inspection Service (FSIS) Microbiology Laboratory Guidebook (MLG) 4.10 for raw ground turkey and the U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) Chapter 5 for PIF. Inclusivity/exclusivity, product consistency and stability, and robustness testing were conducted.
There was no significant difference between the 25 g raw ground turkey and 100 g PIF PhageDx Salmonella Assay and the USDA/FSIS MLG 4.10 and FDA/BAM Chapter 5, respectively. The reporter bacteriophages were specific for Salmonella and infected 108 strains in inclusivity testing. They did not infect 30 non-Salmonella bacteria in exclusivity testing. Robustness testing showed that the method performed well with specific deviations from the standard protocol. Consistency and stability testing demonstrated that the recombinant phage gave consistent results across three production lots and was stable when stored under appropriate conditions for at least eight months.
The data collected in the validation study demonstrate that the PhageDx Salmonella Assay meets the qualifications for PTM status.
The PhageDx Salmonella Assay is a rapid, specific, sensitive assay capable of detecting a wide range of Salmonella spp. with a significantly shorter turn around time than the USDA/FSIS and FDA reference methods.
PhageDx™沙门氏菌检测法基于特定噬菌体对沙门氏菌的感染和荧光素酶报告基因的表达。对于生的碎火鸡肉，结果可在 9.5 小时内产生，对于基于牛奶的粉状婴儿配方（PIF），结果可在 18.5 小时内产生。
进行了 AOAC 经性能验证的方法（PTM）研究，以验证 PhageDx 沙门氏菌检测法在 25g 生碎火鸡肉和 100g PIF 测试部分中对沙门氏菌的检测。
将 PhageDx 沙门氏菌检测法的性能与美国农业部（USDA）食品安全检验局（FSIS）微生物实验室指南（MLG）4.10 比较用于生碎火鸡肉，与美国食品药品监督管理局（FDA）细菌分析手册（BAM）第 5 章比较用于 PIF。进行了包容性/排他性、产品一致性和稳定性以及稳健性测试。
25g 生碎火鸡肉和 100g PIF PhageDx 沙门氏菌检测法与 USDA/FSIS MLG 4.10 和 FDA/BAM 第 5 章分别没有显著差异。报告噬菌体对沙门氏菌具有特异性，在包容性测试中感染了 108 株沙门氏菌。在排他性测试中，它们没有感染 30 株非沙门氏菌。稳健性测试表明，该方法在特定偏离标准方案时表现良好。一致性和稳定性测试表明，重组噬菌体在三个生产批次中产生一致的结果，并在适当条件下储存至少八个月时保持稳定。
验证研究中收集的数据表明，PhageDx 沙门氏菌检测法符合 PTM 状态的资格。
PhageDx 沙门氏菌检测法是一种快速、特异、灵敏的检测法，能够检测广泛的沙门氏菌，其周转时间明显短于 USDA/FSIS 和 FDA 参考方法。
