Evaluation of the Thermo ScientificTM SureTectTMListeria monocytogenes PCR Assay in a Broad Range of Foods and Selected Environmental Surfaces: Pre-Collaborative and Collaborative Study, First Action 2021.05.

BACKGROUND: The Thermo Scientific™ SureTect™ Listeria monocytogenes PCR Assay uses Solaris reagents for performing PCR for the rapid and specific detection of Listeria monocytogenes in a broad range of foods and selected environmental surfaces. OBJECTIVE: To demonstrate reproducibility of the SureTect Listeria monocytogenes PCR Assay in a collaborative study using a challenging matrix, full-fat cottage cheese (25 g). To extend the scope of the method. METHOD: In the collaborative study, the candidate method was compared to the United States Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) Chapter 10 Listeria reference method. The candidate method used two PCR thermocyclers, the Applied Biosystems™ QuantStudio™ 5 Real-Time PCR instrument (QS5) and the Applied Biosystems 7500 Fast Real-Time PCR instrument (7500 Fast). Eighteen participants from 10 laboratories located within the United States and Europe were solicited for the collaborative study, with 12 participants submitting valid data. Three levels of contamination were evaluated for each matrix. Statistical analysis was conducted according to the probability of detection (POD) statistical model. In addition, to extend the scope, six matrix studies were performed comparing the candidate method to the FDA/BAM reference method. One of these matrixes was also compared to the ISO 11290-1:2017 Microbiology of the Food Chain-Horizontal Method for the Detection and Enumeration of Listeria monocytogenes and of Listeria spp.-Part 1: Detection Method Reference Method. RESULTS: In the collaborative study, the difference in laboratory results indicates equivalence between the candidate method and reference method for the matrix evaluated, and the method demonstrated acceptable inter-laboratory reproducibility as determined in the collaborative evaluation. The two PCR instruments used in the study performed equivalently. All presumptive positives were confirmed via the alternative confirmation procedure. In the pre-collaborative studies, the results showed comparable performances between the candidate method and the reference method for all matrixes tested. CONCLUSIONS: Based on the data generated, the method demonstrated acceptable inter-laboratory reproducibility data and statistical analysis. HIGHLIGHTS: Due to the COVID-19 pandemic, some participants had to be trained remotely. Additionally, 25 g full-fat cottage cheese is known to be a challenging matrix to test. No unusual cross-contamination or false positive/negative data were reported, highlighting the ease of use, reproducibility, and robustness of the method.

Evaluation of the Thermo Scientific SureTectTM Listeria Species PCR Assay in a Broad Range of Foods and Selected Environmental Surfaces: Pre-Collaborative and Collaborative Study, First Action 2021.06.

BACKGROUND: The Thermo Scientific SureTect™ Listeria species PCR assay utilizes SolarisTM reagents for performing PCR for the rapid and specific detection of Listeria species in a broad range of foods and selected environmental surfaces. OBJECTIVE: To demonstrate reproducibility of the Thermo Scientific SureTect Listeria species PCR assay in a collaborative study using a challenging matrix, full-fat cottage cheese (25 g), to extend the scope of the method. METHODS: In the collaborative study, the candidate method was compared to the US Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) Ch. 10 Listeria reference method. The candidate method used two PCR thermocyclers, the Applied Biosystems QuantStudio™ 5 Real-Time PCR instrument (QS5) and the Applied Biosystems 7500 Fast Real-Time PCR instrument (7500 Fast). The candidate method included its own confirmation procedure. Eighteen participants from 10 laboratories located within the United States and Europe were solicited for the collaborative study, with 12 participants submitting valid data. Statistical analysis was conducted according to the probability of detection (POD) statistical model. In addition, in order to extend the scope of the method, seven matrix studies were performed comparing the candidate method to the FDA/BAM reference method. One of these matrixes was also compared to the ISO 11290-1:2017 Microbiology of the food chain-Horizontal method for the detection and enumeration of Listeria monocytogenes and of Listeria spp.-Part 1: Detection method reference method. RESULTS: In the collaborative study, the difference in laboratory results indicates equivalence between the candidate method and reference method for the matrix evaluated and the method demonstrated acceptable inter-laboratory reproducibility as determined in the collaborative evaluation. The two PCR instruments used in the study performed equivalently. All presumptive positives were confirmed via the alternative confirmation procedure. In the pre-collaborative studies, the results showed comparable performances between the candidate method and the reference method for all matrixes tested. CONCLUSION: Based on the data generated, the method demonstrated acceptable inter-laboratory reproducibility data and statistical analysis. HIGHLIGHTS: Due to the COVID-19 pandemic, some participants had to be trained remotely. Additionally, 25 g full-fat cottage cheese is known to be a challenging matrix to test. No unusual cross-contamination, or false-positive/negative data was reported, highlighting the ease of use, reproducibility, and robustness of the candidate method.

Evaluation of the Thermo Scientific SureTect Salmonella Species PCR Assay in a Broad Range of Foods and Select Environmental Surfaces: Pre-Collaborative and Collaborative Study: First Action 2021.02.

BACKGROUND: The Thermo Scientific™ SureTect™ Salmonella species PCR Assay utilizes Solaris™ reagents for performing PCR for the rapid and specific detection of Salmonella species in a broad range of foods and select environmental surfaces. OBJECTIVE: The aims were to demonstrate the reproducibility of the Thermo Scientific SureTect Salmonella species PCR Assay in a collaborative study using a challenging matrix, cocoa powder, and to extend the scope of the method. METHOD: In the collaborative study, the candidate method was compared to the US Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) Chapter 5 Salmonella reference method. The candidate method used two PCR thermocyclers, the Applied Biosystems™ QuantStudio™ 5 Real-Time PCR instrument (QS5) and the Applied Biosystems 7500 Fast Real-Time PCR instrument (7500 Fast). Fourteen participants from nine laboratories located within the United States and Europe were solicited for the collaborative study, with 12 participants submitting valid data. Three levels of contamination were evaluated for each matrix. Statistical analysis was conducted according to the probability of detection statistical model. In addition, 11 matrix studies were performed comparing the candidate method to the FDA/BAM Chapter 5 or US Department of Agriculture, Food Safety and Inspection Service, Microbiology Laboratory Guidebook 4.10 Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg, and Siluriformes (Fish) Products and Carcass and Environmental Sponges reference method. Nine of these matrices were also compared to the EN ISO 6579-1:2017/Amd.1:2020(E) Microbiology of the food chain-Horizontal method for the detection, enumeration and serotyping of Salmonella-Part 1: Detection of Salmonella spp.-AMENDMENT 1: Broader range of incubation temperatures, amendment to the status of Annex D, and correction of the composition of MSRV and SC reference method. RESULTS: In the collaborative study, the difference in laboratory results indicates equivalence between the candidate method and reference method for the matrix evaluated, and the method demonstrated acceptable interlaboratory reproducibility as determined in the collaborative evaluation. False-positive and false-negative rates were determined for the matrix and produced values of <2%. The two PCR thermocyclers (QS5, 7500 Fast) performed equivalently. There were no result differences between candidate method confirmations and reference method confirmations. In the pre-collaborative matrix extension, the results from the matrix studies showed a comparable performance between the candidate method and the tested reference methods. CONCLUSIONS: Based on the data generated, the method demonstrated acceptable interlaboratory reproducibility data and statistical analysis. HIGHLIGHTS: Due to the COVID-19 pandemic, some participants had to be trained remotely. Additionally, 375 g cocoa powder is known to be a challenging matrix for PCR methods. No unusual cross-contamination or false-positive/negative was reported, highlighting the ease of use, reproducibility, and robustness of the method.